JPH07128904A - Electrophotographic toner and its production - Google Patents

Abstract

PURPOSE:To produce an electrophotographic toner having a narrow grain size distribution, capable of pulverization. excellent in fluidity and further excellent in cleanability by a cleaning blade by aggregating the toner grains while interposing an inorg. material between the grains, deforming the aggregate and the chemically dissolving off the inorg. material to decompose the aggregate. CONSTITUTION:The toner grains (t) with water W infiltrated into the clearance are heated by an oven, etc., hence the water W is vaporized to form a cavity H in the clearance between the grains (t), and a capillary pressure is generated in the direction contracting an interface between the water W surrounding the cavity H and air since the interface is curved. The grains (t) softened by heating are pulled, deformed and aggregated. The aggregate is introduced into acid or alkali to dissolve off the inorg. material, hence the aggregate is decomposed, and an electrophotographic toner with the grains deformed is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner used in an image forming apparatus to which a so-called electrophotographic method is applied, such as an electrostatic copying machine and a laser beam printer, and a manufacturing method thereof. .

[0002]

2. Description of the Related Art A conventional electrophotographic toner is obtained by melt-kneading a fixing resin such as a styrene-acrylic copolymer and carbon black as a coloring agent and other additives. Then, it is manufactured by crushing and classifying. However, since such a pulverized toner has a wide particle size distribution, it is difficult to make the charging uniform, and it is difficult to obtain an image with high resolution because of the large particle size. Further, since the shape of the obtained particles is irregular, the fluidity of the toner is generally low and there is a problem that blocking or the like is likely to occur.

Therefore, recently, as a method for producing an electrophotographic toner replacing the above-mentioned pulverization method, a method for producing a toner utilizing the production of resin particles by a suspension polymerization method, a dispersion polymerization method or a spray drying method has been proposed. Among them, the method for producing a toner using the suspension polymerization method is a water-insoluble polymerizable monomer that is a base of the fixing resin, a polymerization initiator soluble in the monomer, and a colorant and other additives. Is a method of polymerizing a polymerizable monomer by preparing a liquid monomer phase (oil phase) containing the above and heating it while suspending and dispersing it in an aqueous dispersion medium such as water in the form of droplets.

Further, in the method for producing a toner using the dispersion polymerization method, the polymerizable monomer which is the base of the fixing resin and the colorant and other additives are dissolved in the polymerizable monomer. This is a method in which the polymer is dissolved together with the dispersion stabilizer in a medium in which it is not dissolved, and is polymerized under stirring. Further, a method for producing a toner using a spray drying method is a spray drying liquid obtained by dissolving or dispersing the fixing resin and a colorant and other additives in an appropriate solvent using a spraying device. It is a method of drying and removing the solvent while spraying in a mist state.

All of the electrophotographic toners produced by these methods have a narrow particle size distribution and can be made smaller by changing the conditions, so that they have excellent charging characteristics and high quality. There is an advantage that an image can be obtained. It also has excellent productivity because it does not require classification. However, since the toner particles for electrophotography obtained by these methods have almost spherical particles, there is a problem that they are excellent in fluidity but poor in cleaning property. That is, as described above, when the spherical toner remains on the surface of the photoconductor after image formation, it is difficult to remove it with the cleaning blade that is brought into pressure contact with the surface of the photoconductor.

Therefore, the above-mentioned toner particles having a substantially spherical shape are once agglomerated by heating or pressurizing, and then the agglomerates are forcibly disintegrated by using a jet mill or the like, so that they are deformed. A method for producing the above-mentioned toner particles has been proposed (for example, JP-A-2-167564, JP-A-3-126956, and JP-A-3-248163).
No.

When the electrophotographic toner is manufactured by these methods, if the heating temperature or the pressure applied is too high, the toner particles are strongly fused with each other and are in a substantially integrated state. Not only are the aggregates crushed from the interface between the toner particles, but also the toner particles themselves are crushed, and particles having a smaller particle size than the original toner particles are generated. Further, particles having a larger particle size than the original toner particles are also generated, in which the plurality of toner particles are still fused.

For this reason, the toner particles modified by the above method cannot maintain the initial particle size and particle size distribution, and the particle size distribution is widened like the pulverized toner, so that the charging is made uniform. There is a problem that it becomes difficult, or classification becomes necessary and productivity deteriorates. Therefore, if the heating temperature and the pressurizing pressure at the time of aggregation are lowered, the above-mentioned problems can be solved, but the obtained toner particles remain almost spherical and are hardly deformed, so that the cleaning property cannot be improved so much.

There is an improved proposal for improving the disintegration property of the agglomerates by mixing the toner particles at the time of aggregation with fine particles of an inorganic substance having a smaller particle diameter to prevent the toner particles from being fused with each other. Proposed (JP-A-2-273757,
See Japanese Patent Application Laid-Open No. 2-275470). In this method, even if the toner particles are agglomerated to a certain degree, the fine particles of the inorganic substance prevent the toner particles from being fused to each other. As it is worn, it does not contain particles with a larger particle size than the original toner particles, and since it is sufficiently deformed,
It also has excellent cleaning properties.

However, in the above method, since a jet mill or the like is used to disintegrate the aggregates, it is still impossible to prevent the generation of the crushed toner particles having a smaller particle size than the original toner particles. Further, a large amount of fine-particled inorganic material remains on the surface of the manufactured toner particles, which adversely affects the characteristics of the toner.

In particular, since untreated inorganic substances generally show hydrophilicity, the moisture resistance and environmental resistance stability of toner particles are significantly deteriorated. Further, the hydrophobically treated inorganic substance does not cause the above problems, but in any case, the inorganic substance remains on the surface of the toner particles in a large amount, which adversely affects the charging property of the toner. The present invention has been made in view of the above circumstances, and retains the advantage of spherical toner particles that the particle size distribution is narrow and the particle size can be reduced, and that the fluidity is excellent, and It is an object of the present invention to provide an electrophotographic toner having excellent cleaning properties with a cleaning blade, and a method for producing the electrophotographic toner.

[0012]

In order to solve the above problems, the present inventors do not forcibly crush the agglomerates of toner particles but decompose them without affecting the toner particles themselves. I examined the method. As a result, after the toner particles are aggregated with the inorganic substances interposed between the toner particles to deform the toner particles, the inorganic substances are chemically dissolved and removed to decompose the aggregates. The inventors have found that toner particles can be obtained that are sufficiently deformed while maintaining the initial particle size and particle size distribution without causing problems such as crushing of toner particles, and have completed the present invention.

That is, the electrophotographic toner of the present invention is a dispersion in which at least a polymerizable monomer is dissolved in a medium in which the polymerizable monomer is dissolved but the polymer is not dissolved, and which is polymerized under stirring. The substantially spherical toner particles produced by the polymerization method are agglomerated in a state in which an inorganic substance is present between the toner particles to form a different shape, and then the inorganic substance is chemically dissolved,
It is characterized by being obtained by decomposing the aggregate by removing it.

The toner for electrophotography according to the present invention having the above-mentioned constitution is prepared by the dispersion polymerization method. The toner particles having a particularly narrow particle size distribution and having a substantially monodispersed particle size distribution are used as a raw material, and an inorganic material is added to the toner particles. After agglomerating in the state of being interposed, by chemically dissolving and removing the inorganic substances, it was deformed while maintaining the initial particle size and particle size distribution, so the particle size distribution was extremely narrow and the particle size was made smaller. In addition to being excellent in fluidity, it is also excellent in cleaning performance with a cleaning blade. Therefore, the electrophotographic toner of the present invention has extremely excellent characteristics in terms of charging characteristics and image quality. Further, since the electrophotographic toner of the present invention does not require any classification, the yield is high and the productivity is extremely excellent.

Further, in the method for producing an electrophotographic toner of the present invention, spherical toner particles are agglomerated in a state where an inorganic substance is present between the toner particles so as to be deformed, and then the inorganic substance is chemically dissolved and removed. And a step of decomposing the aggregates. In the method for producing the electrophotographic toner of the present invention having the above structure, the suspension polymerization method,
Spherical toner particles produced by the dispersion polymerization method, spray drying method, etc. are aggregated with an inorganic substance interposed, and then the inorganic substance is chemically dissolved and removed to obtain the initial particle size and particle size distribution. Since it is deformed while maintaining its shape, the advantages of spherical toner particles that the particle size distribution is narrow and the particle size can be made small, and that the fluidity is excellent, are retained and the cleaning property by the cleaning blade is also excellent. It is possible to manufacture an electrophotographic toner. Further, since the electrophotographic toner manufactured by the above manufacturing method does not require any classification, the yield is high and the productivity is excellent. Moreover, according to the above-mentioned manufacturing method, there is an advantage that the degree of deformation can be freely adjusted by controlling the degree of aggregation. Further, in the above-mentioned manufacturing method, there is an advantage that energy cost can be reduced because a mechanical crushing means such as a jet mill is unnecessary.

When the toner particles produced by the suspension polymerization method are used as the substantially spherical toner particles used in the method for producing an electrophotographic toner of the present invention, an inorganic substance interposed between the toner particles at the time of aggregation is used. In the above suspension polymerization method, it is preferable to chemically precipitate from the aqueous dispersion medium on the surface of the monomer phase droplets suspended and dispersed in the aqueous dispersion medium.

In the toner particles produced by the suspension polymerization method by this method, since inorganic substances are deposited in a film form on the entire surface of the toner particles, the toner particles are brought into contact with each other and fused when they are aggregated. Can be reliably prevented. Further, the inorganic substance intervening between the toner particles at the time of aggregation can be chemically deposited from the solution on the surface of the toner particles formed in advance.

According to this method, not only the toner particles produced by the suspension polymerization method but also the toner particles produced by other methods can deposit the inorganic substance in the form of a film on the entire surface thereof. When the toner particles are aggregated, it is possible to reliably prevent the toner particles from contacting and fusing.
Further, as a method of aggregating the toner particles and the inorganic substance,
A method in which both are heated to the glass transition temperature of the resin portion of the toner particles or higher in the presence of water is suitably adopted.

According to the above method, the toner particles heated above the glass transition temperature are deformed due to the capillary pressure generated when the water entering the gaps between the toner particles is vaporized by heating. The degree of irregularity of each can be made almost uniform. The present invention will be described below.
As described above, the point of the present invention is to agglomerate spherical toner particles by aggregating them in a state in which an inorganic substance is present between the toner particles so as to deform the inorganic substance, and then chemically dissolving and removing the inorganic substance. Is to disassemble.

As the inorganic substance to be aggregated together with the spherical toner particles, there is adopted a chemical treatment after deforming, that is, a substance which is easily dissolved and removed with an acid or an alkali. Specific examples of the inorganic substance include, but are not limited to, tricalcium phosphate, calcium sulfate, magnesium carbonate, barium carbonate, calcium carbonate, aluminum hydroxide, silicon dioxide, and phosphonite. Any of the various compounds of can be used. These may be used alone or in combination of two or more. Of the above, each compound of tribasic calcium phosphate, calcium sulfate, magnesium carbonate, barium carbonate, calcium carbonate and aluminum hydroxide, and apatite is one that dissolves in acid, and silicon dioxide is one that dissolves in alkali. .

As a method of interposing the above-mentioned inorganic substance between the toner particles, (A) the toner particles and the fine particles of the inorganic substance are
To be blended in a predetermined ratio, (B) to chemically deposit the inorganic substance on the surface of the toner particle, (C) to blend the fine particle of the inorganic substance when producing the toner particle by the suspension polymerization method described later. , The surface of the droplets of the monomer phase dispersed in the aqueous dispersion medium, the fine particles of the inorganic substance are attached, (D) when the toner particles are produced by the suspension polymerization method, the monomer phase dispersed in the aqueous dispersion medium Examples of the method include chemically depositing an inorganic substance on the surface of the liquid droplets.

Of the above, the methods (C) and (D) are limited to the suspension polymerization method, but the methods (A) and (B) use the toner particles produced by the suspension polymerization method. The present invention can be applied to toner particles manufactured by various manufacturing methods. Further, according to the methods (B) and (D), as described above, since the inorganic substance is deposited in the form of a film on the entire surface of the toner particles, the toner particles come into contact with each other and are fused when they are aggregated. There is an advantage that it can be surely prevented.

In order to deposit the inorganic substance on the surface of the toner particles or the droplets of the monomer phase, for example, an inorganic substance which is dissolved in an acid and precipitated in an alkali is used among the inorganic substances exemplified above.
First, an acid is added to dissolve the inorganic substance, and then, in the presence of toner particles or droplets of a monomer phase, an alkali is added to precipitate the inorganic substance, or vice versa. Using an inorganic substance that precipitates with lactic acid, first, an alkali is added to dissolve the inorganic substance, and then, in the presence of toner particles or droplets of a monomer phase, an acid is added to precipitate the inorganic substance. To be done.

The particle size of the inorganic fine particles used in the methods (A) and (C) must be smaller than the particle size of the toner particles. It is even more preferred to be present. When the particle size of the inorganic fine particles exceeds the above range, the surface of the toner particles cannot be uniformly covered with the inorganic fine particles, and the toner particles may come into contact with each other to be fused.

The addition amount of the inorganic substance varies depending on each method, but in any method, it is desirable to add the inorganic substance in an amount that can cover at least the surface of the toner particles evenly. As a method of agglomerating spherical toner particles with an intervening inorganic material as described above, (a) a method by pressing (pressurizing) with or without heating, (b) toner particles and an inorganic material In the presence of the above, a method of heating to above the glass transition temperature of the resin portion of the toner particles, and the like.

The pressing pressure in the pressing method (a) is not particularly limited, and depends on the degree of deformation and the type of fixing resin, but in the case of a press without heating, it is 10 to 500 kg / cm. ^{About 2} is preferable. If the pressing pressure is less than the above range, the toner particles may not be sufficiently aggregated or deformed, and if the pressing pressure exceeds the above range, the toner particles may be broken.

On the other hand, in the case of a press accompanied by heating, the pressing pressure is 0.1-10 kg /, although it varies depending on the degree of deformation, the type of fixing resin, the heating temperature and the like.
cm ² is preferable. If the pressing pressure is less than the above range, the toner particles may still not be sufficiently aggregated and deformed, and conversely, if the pressing pressure exceeds the above range, the toner particles may be fused and integrated. There is.

The heating temperature of the press with heating is
In order to facilitate the deformation with the pressing pressure, it is desirable that the temperature is not lower than the glass transition temperature of the resin portion of the toner particles, as in the case of (b) heating. Among the agglomeration methods of the toner particles
The process of toner particle aggregation → deformation in the method (b) is modeled in FIGS. 1 (a) to 1 (c). In these drawings, the inorganic substances are omitted for convenience, but in reality, the inorganic substances are deposited in a film form on the surface of the toner particles t (when the method (B) or (D) is adopted). )
Alternatively, the inorganic fine particles having a smaller particle size are present between the toner particles t (when the method (A) or (C) is adopted).

First, as shown in FIG. 1 (a), when toner particles t (actually in a toner cake state) in which water W has entered the gap are heated using an oven or the like, the water W is vaporized, and cavities H are generated in the gaps between the toner particles t as shown in FIG. 1 (b). When the cavities H are generated in the gaps between the toner particles t, the interface of the water W surrounding the cavities H with the air is curved, so that a capillary pressure (surface tension) is generated in the direction of contracting the interface.

Then, the toner particles softened by heating are stretched and deformed as shown by the white arrow in FIG. 1 (c), aggregated and deformed. Of the above process,
Since the gaps between the toner particles t after the formation of the cavities H communicate with each other, the reduction of the water W in the gaps between the toner particles t progresses relatively evenly. Further, the gap between the toner particles t communicating with each other is filled with high-temperature steam, so that the heat can be transferred quickly. Therefore, according to the above method (b), the degree of deformation of each toner particle is made substantially uniform, so that a toner for electrophotography which is more uniformly deformed than the pressing method can be obtained.

The heating temperature of the toner cake in the method (b) is limited to the glass transition temperature of the resin portion of the toner particles t or higher, as can be seen from the above mechanism. If the heating temperature is lower than the glass transition temperature of the resin portion, the toner particles t cannot be aggregated and deformed by the above mechanism. The toner particles are aggregated as described above, and the deformed aggregate is put into an acid or an alkali to chemically dissolve and remove the inorganic substances interposed between the toner particles,
The aggregate is decomposed to obtain a deformed electrophotographic toner. In addition, stirring may be performed to promote decomposition.

The electrophotographic toner manufactured as described above retains the advantages of the spherical toner particles that the particle size distribution is narrow and the particle size can be reduced, and that the fluidity is excellent. The cleaning property by the cleaning blade is also excellent. In particular, the toner for electrophotography of the present invention, which is produced by using the toner particles by the dispersion polymerization method described later as a raw material, has a particle size distribution that is almost monodisperse, and therefore has extremely excellent characteristics in terms of charging characteristics and image quality. Will have.

The spherical toner particles which are the basis of the electrophotographic toner used for the modification are spherical particles made of a fixing resin and various additives added in a predetermined amount.
The above spherical toner particles can be produced by various production methods, including a water-insoluble polymerizable monomer which is a base of the fixing resin,
A liquid monomer phase (oil phase) containing a soluble polymerization initiator and various additives is prepared and heated while suspending and dispersing it in an aqueous dispersion medium such as water in the form of droplets. Then, the suspension polymerization method of polymerizing the polymerizable monomer, the polymerizable monomer that is the base of the fixing resin, the polymerization initiator, and various additives are dissolved in the polymerizable monomer. However, the polymer is dissolved in a medium in which it is not dissolved, together with a dispersion stabilizer, and a dispersion polymerization method in which polymerization is performed under stirring. The fixing resin and various additives are dissolved or dispersed in a suitable solvent. The spray-dried solution obtained by drying and removing the solvent while spraying the obtained spray-dried liquid in a mist state using a spraying device is preferably adopted. All of the spherical toner particles produced by these three methods have a narrow particle size distribution and can be made smaller by changing the conditions, so that they have excellent charging characteristics and high quality images can be obtained. The advantage is that It also has excellent productivity because it does not require classification.

Since the spherical toner particles produced by the dispersion polymerization method in particular show a substantially monodispersed particle size distribution as described above, the toner for electrophotography of the present invention is produced by the dispersion polymerization method. Spherical toner particles are used as a raw material. In the manufacturing method of the present invention,
The toner particles produced by each of the above methods can be used, and spherical toner particles produced by methods other than the above can also be used.

As the polymerizable monomer used as the base of the fixing resin used in the above method, various radical-polymerizable polymerizable monomers can be used. As the fixing resin used in the other method, a polymer of the above polymerizable monomer is used. Examples of such a polymerizable monomer include monovinyl aromatic monomer, acrylic monomer, vinyl ester monomer, vinyl ether monomer, diolefin monomer, monoolefin monomer. ,
Various conventionally known compounds such as halogenated olefin-based monomers and polyvinyl-based monomers can be used.

As the monovinyl aromatic monomer, the following general formula (1):

[0037]

[Chemical 1]

(In the formula, R ¹ is a hydrogen atom, a lower alkyl group or a halogen atom, and R ² is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group, a vinyl group, a sulfo group, or a sodium sulfo group. A monovinyl aromatic hydrocarbon represented by a nato group, a potassium sulfonato group or a carboxyl group), such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o, m, p-chlorostyrene, p. -Ethyl styrene, sodium styrene sulfonate, divinyl benzene and the like.

The acrylic monomer has the following general formula:
(2):

[0040]

[Chemical 2]

(Wherein R ³ is a hydrogen atom or a lower alkyl group, R ⁴ is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms,
It represents a hydroxyalkyl group, a vinyl ester group or an aminoalkyl group. ) An acrylic monomer represented by, for example, acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
-Ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, butyl γ-hydroxyacrylate, butyl δ-hydroxyacrylate, β-hydroxy Ethyl methacrylate, γ-aminopropyl acrylate,
Examples include γ-N, N-diethylaminoacrylic acid propyl ester, ethylene glycol dimethacrylic acid ester, and tetraethylene glycol dimethacrylic acid ester.

The vinyl ester-based monomer is represented by the following general formula (3):

[0043]

[Chemical 3]

(In the formula, R ⁵ represents a hydrogen atom or a lower alkyl group.) Examples thereof include vinyl ester monomers, such as vinyl formate, vinyl acetate and vinyl propionate. The vinyl ether-based monomer has the following general formula (4):

[0045]

[Chemical 4]

(In the formula, R ⁶ represents a monovalent hydrocarbon group having up to 12 carbon atoms.) Examples thereof include vinyl ether type monomers such as vinyl methyl ether, vinyl ethyl ether and vinyl-n. -Butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like. The diolefin-based monomer has the following general formula (5):

[0047]

[Chemical 5]

(Wherein R ⁷ , R ⁸ and R ⁹ are the same or different and each represents a hydrogen atom, a lower alkyl group or a halogen atom), and examples thereof include a diolefin monomer. , Isoprene, chloroprene and the like. As a mono-olefin monomer,
The following general formula (6):

[0049]

[Chemical 6]

(In the formula, R ¹⁰ and R ¹¹ are the same or different and each represents a hydrogen atom or a lower alkyl group.) A monoolefin monomer represented by the formula (I) is exemplified, such as ethylene, propylene and butene-1. , Pentene-1, 4-methylpentene-1 and the like. Examples of the halogenated olefin-based monomer include vinyl chloride and vinylidene chloride.

Further, examples of the polyvinyl monomer include divinylbenzene, diallyl phthalate, tricyanurate and the like. These can be used alone or in combination of two or more. For example, when a toner containing the most common styrene-acrylic fixing resin is produced, styrene and an acrylic monomer may be used in combination as the polymerizable monomer.

In the method (1), examples of the polymerization initiator for initiating the polymerization of the above polymerizable monomer include azobisisobutyronitrile and 2,2'-azobis- (2,4).
-Dimethylvaleronitrile), 2,2'-azobis-
(4-methoxy-2,4-dimethylvaleronitrile),
2,2'-azobis- (2-cyclopropylpropionitrile), 2,2'-azobis- (2-methylpropionitrile), 2,2'-azobis- (2-methylbutyronitrile), 1 , 1'-azobis- (cyclohexane-
1-carbonitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, dimethyl-2,
Azo compounds such as 2'-azobis (2-methylpropionate); cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, lauroyl peroxide and other peroxides In addition to the above, a conventionally known photopolymerization initiator can be used when the polymerization is carried out by irradiation with ultraviolet rays or visible rays. These are used alone,
Two or more kinds can be used in combination. As the polymerization initiator used in the suspension polymerization method, those that are insoluble in the aqueous dispersion medium and compatible with the polymerizable monomer are preferably adopted from the above.

The amount of the polymerization initiator used is 10
The amount is 0.001 to 10 parts by weight, preferably 0.01 to 0.5 parts by weight, relative to 0 parts by weight. It is also possible to initiate the polymerization using γ rays, accelerated electron beams, etc.
In this case, the polymerization initiator may not be used. Also,
The polymerization may be initiated by combining ultraviolet rays and various photosensitizers.

Among the additives, various conventionally known colorants can be used as the colorant for imparting color to the toner. The colorant may be blended in a predetermined amount in advance when the toner particles are produced by each of the above-mentioned methods, and the uncolored toner particles are first produced by each of the above-mentioned methods, May be dyed later (at any stage before or after the modification) with a colorant.

In the suspension polymerization method, the colorant to be preliminarily blended in the monomer phase is not limited to this, but may be, for example, <black> carbon black or nigrosine dye (C.I.
No. 50415B), Lamp Black (C.I. No. 7)
7266), oil black, azo oil black, <red> DuPont oil red (CI. No. 2610)
5), Rose Bengal (CI. No. 45435), Orient Oil Red # 330 (CI. No. 605)
0), <yellow> chrome yellow (CI. No. 1409)
0), quinoline yellow (C.I.O. 47005), <green> malachite green oxalate (C.I.N.
o. 42000), <blue> chalco oil blue (CI No. azoec
Blue 3), aniline blue (C.I. No. 5040)
5), methylene blue chloride (C.I. No. 520)
1), phthalocyanine blue (C.I. No. 7416)
0), Ultramarine Blue (C.I. No. 7710)
3), etc. These are used alone,
Two or more kinds can be used in combination. The colorant is preferably used in a proportion of 1 to 20 parts by weight per 100 parts by weight of the polymerizable monomer.

Among the above colorants, in the case of a black toner, carbon black, particularly carbon black which has been subjected to a surface treatment to improve its affinity with the polymerizable monomer, is most preferable. Examples of the surface treatment for improving the affinity of carbon black with the polymerizable monomer include a coupling treatment with a coupling agent and a grafting treatment with a polymerizable monomer.

In the dispersion polymerization method of (1), a dye that is more soluble in the polymerizable monomer than the medium is preferably used as the colorant to be preliminarily blended in the reaction system. Examples of the dye include oil-soluble dyes. The oil-soluble dye is transferred from the medium to the polymer when the amount of the monomer is reduced due to the progress of polymerization, so that efficient dyeing can be performed. Specific examples of oil-soluble dyes are shown below. <Black dye> Black FS-Special A, Black S, Black # 103, Black # 107, Black #
215, Black # 141 (all are trade names manufactured by Chuo Gosei Kagaku Co., Ltd.), OPLAS Black HZ, Oplas Black # 836, and Oplas Black # 838 (all trade names manufactured by Orient Chemical Industry Co., Ltd.). <Red dye> MACROLEX red 5B,
Macrolex Red Violet R (all are trade names manufactured by Bayer), Sumiplast Red AS, Samiplast Tread B-2, Samiplast Red HLG-Z (all trade names manufactured by Sumitomo Chemical Co., Ltd.), Oprah Thread RR, Oprah Thread # 330 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.), Red 6B, Red T
R-71 (all are trade names of Chuo Gosei Kagaku KK). <Orange dye> Macrolex Orange 3G, Macrolex Orange R (all are brand names manufactured by Bayer), Orange S, Orange R, Orange # 826N (all are brand names manufactured by Chuo Synthetic Chemicals), Oplas Orange PS , Oplas Orange RR (trade name of Orient Chemical Industry Co., Ltd.), Samiplast Orange HRP (trade name of Sumitomo Chemical Industry Co., Ltd.). <Yellow dye> Macrolex Yellow 6G, Macrolex Yellow R (all are trade names manufactured by Bayer), Yellow D, Yellow GE, Yellow # 189 (all are trade names manufactured by Chuo Synthetic Chemicals), Samiplast Yellow GC ,
Samiplast Yellow R (all are trade names of Sumitomo Chemical Co., Ltd.), Oplus Yellow 3G, Oplus Yellow # 1
30 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). <Purple dye> Macrolex Violet 3R, Macrolex Violet B (both trade names manufactured by Bayer), Violet MVB (trade name manufactured by Chuo Gosei Kagaku), Samiplast Violet RR, Samiplast Violet B (all Sumitomo) (Chemical Industry Co., Ltd.), Oplus Violet # 370, Oplus Violet #
732 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). <Blue Dye> Macrolex Blue RR (trade name of Bayer), Blue BO, Blue # 8B (all are trade names of Chuo Gosei Kagaku), Samiplast Blue OR, Samiplast Blue GP, Samiplast Blue S (All are trade names manufactured by Sumitomo Chemical Co., Ltd.), Oplus Blue IIN, and Oplas Blue # 630 (all are trade names manufactured by Orient Chemical Co., Ltd.). <Green dye> Macrolex Green 5B, Macrolex Green G (all are trade names manufactured by Bayer), Green # 550, Green # 201 (all are trade names manufactured by Chuo Synthetic Chemicals), Samiplast Green G (Sumitomo) Chemical Industry Co., Ltd. product name), Oplus Green # 502, Oplus Green # 503 (all are product names of Orient Chemical Industry Co., Ltd.). <Brown Dye> Brown PB, Brown SG (all are trade names of Chuo Gosei Kagaku), Oplas Brown # 430,
Oplas Brown # 431 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.).

The amount of the oil-soluble dye used varies depending on the desired degree of color density, but is usually 1 to 10 ^-9 times, especially 10 ^-6 times the weight of the reaction solution 1. It is preferable. Further, in the spray-drying method, as the colorant to be preliminarily mixed in the solution, any of the various colorants exemplified above can be used.

On the other hand, in order to dye the uncolored toner particles later, for example, the uncolored toner particles may be dispersed together with a dye such as a dispersible dye in an aqueous medium and stirred at a predetermined temperature for a predetermined time. Examples of dispersible dyes used for dyeing include azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes and phthalocyanine dyes. The dispersible dye preferably has a high affinity for the polymer constituting the toner particles and can dye the toner particles firmly. The amount of the dispersible dye used varies depending on the desired degree of coloring density, but is usually preferably 2% by weight or more, and more preferably 4% by weight or more, relative to the toner particles. Water is usually used as the aqueous medium, but when the dispersibility of the toner particles and the dye is poor, a suitable organic solvent may be added in a small amount. The amount of the aqueous medium used is preferably 500 parts by weight or more based on 100 parts by weight of the toner particles.

Typical additives other than the above colorants include charge control agents and offset preventing agents. The charge control agent is blended to control the triboelectric chargeability of the toner, and there are two types, one for controlling the positive charge and one for controlling the negative charge. As the charge control agent for controlling the positive charge, an organic compound having a basic nitrogen atom, such as a basic dye, an aminopyrine, a pyrimidine compound, a polynuclear polyamino compound, an aminosilane, or the like, a filler surface-treated with each of the above compounds, or the like Can be given.

Charge control agents for controlling negative charge include nigrosine base (CI5045) and oil black (CI26150).
), An oil-soluble dye such as Bontron S or Spiron Black; a charge control resin such as a styrene-styrene sulfonic acid copolymer; a compound containing a carboxy group (for example, a metal chelate of alkylsalicylic acid), a metal complex dye, a fatty acid metal Examples thereof include soap, resin acid soap, and metal salt of naphthenic acid.

The charge control agent is used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the polymerizable monomer. The offset preventing agent is blended in order to impart an offset preventing effect to the toner. Examples of the anti-offset agent include aliphatic hydrocarbons, aliphatic metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, and various waxes. Among them, the weight average molecular weight is 1000 to 100
An aliphatic hydrocarbon of about 00 is preferable. In particular,
One or a combination of two or more of low molecular weight polypropylene, low molecular weight polyethylene, paraffin wax, low molecular weight olefin polymer composed of olefin units having 4 or more carbon atoms, silicone oil and the like is suitable.

The offset preventive agent is a polymerizable monomer 100.
0.1 to 10 parts by weight, preferably 0.5
Used at a rate of ~ 8 parts by weight. In addition to the above components, examples of components that can be added to the monomer phase include magnetic powder and a crosslinking agent. When magnetic powder is added, a magnetic toner as a one-component developer can be obtained.

The magnetic substance is a substance that is strongly magnetized in that direction by a magnetic field and is preferably chemically stable, and is a fine powder having a particle size of 1 μm or less, particularly about 0.01 to 1 μm. Good. Typical magnetic materials include iron oxides such as magnetite, hematite, and ferrite,
Metals such as iron, cobalt and nickel, or with these metals, aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth,
Cadmium, calcium, manganese, selenium, titanium,
Examples thereof include alloys with tungsten and vanadium, and mixtures thereof.

The mixing amount of the magnetic substance powder is 10
20 to 300 parts by weight, preferably 50 to 0 parts by weight
It is preferable to use it in a proportion of 150 parts by weight. The cross-linking agent is
It is added to crosslink the fixing resin to improve the mechanical or thermal characteristics of the electrophotographic toner. For example, divinyl compounds such as divinylbenzene; diallyl phthalate, diallyl isophthalate, diallyl adipate, diallyl glyco. Rate, diallyl maleate, diallyl sebacate and other diallyl compounds; triallyl phosphate, triallyl aconitate, triallyl cyanurate, trimellitic acid allyl ester, pyromellitic acid allyl ester and other triallyl compounds; 1,6-hexanediol Diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate,
Diacrylate compounds such as diethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, butylene glycol diacrylate, pentaerythritol diacrylate, 1,4-butanediol diacrylate; trimethylolpropane triacrylate, pentaerythritol triacrylate, etc. Triacrylate compound;
Dimethacrylate compounds such as 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate;
Trimethacrylate compounds such as trimethylolpropane trimethacrylate; poly (meth) acrylates such as dipentaerythritol hexaacrylate, tetramethylolmethane tetraacrylate, N, N, N ′, N′-tetrakis (β-hydroxyethyl) ethylenediamine, etc. ) Acrylate compounds; allyl acrylate,
Allyl-acrylic compounds such as allyl methacrylate;
Examples thereof include acrylamide compounds such as N, N'-methylenebisacrylamide and N, N'-methylenebismethacrylamide, and prepolymers such as polyurethane acrylate, epoxy acrylate, polyether acrylate and polyester acrylate.

The crosslinking agent is used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer. In addition, various additives such as a stabilizer may be blended in an appropriate ratio. In the suspension polymerization method, the aqueous dispersion medium for dispersing the monomer phase containing each of the above components in the form of droplets includes water, or a mixed solvent containing water as a main component and incompatible with the monomer phase, Water is most preferably adopted.

A dispersion stabilizer is preferably added to the above aqueous dispersion medium for the purpose of stabilizing the dispersibility of the monomer phase droplets. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol and the above-mentioned poorly water-soluble inorganic fine particles. Considering the environmental stability, fluidity, charging characteristics, etc. of the toner, the surface of the toner particles Inorganic fine particles that are poorly water-soluble are preferably used, rather than water-soluble polymers that may be taken up by and become hygroscopic on the surface. The addition amount of the dispersion stabilizer may be similar to the conventional amount.

In order to obtain a good dispersed state of the monomer phase, it is preferable to add a surfactant to the aqueous dispersion medium. The surfactant is preferably added after addition of the monomer phase in order to prevent bubbles from being caught. As the surfactant, various conventionally known anionic, cationic or nonionic surfactants can be used. However, considering that the intended toner particle size is 10 μm or less, the suspension-dispersing ability is improved. It must be excellent, and it is desirable that it be easily removed from the toner in order not to affect the characteristics of the toner after manufacturing. The surfactant is added in an appropriate ratio according to the ratio of the monomer phase and the aqueous dispersion medium.

In the dispersion polymerization method, the polymerizable monomer is dissolved but the polymer is not dissolved. Examples of the medium include water; lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; ethylene glycol and propylene. Polyhydric alcohols such as glycol, butanediol, diethylene glycol and triethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; esters such as ethyl acetate. .

These media can be used alone or in combination of two or more. The medium preferably used in the present invention includes lower alcohols such as ethanol, water or a mixed medium of water and lower alcohol. In the above mixed medium, the weight ratio of water to lower alcohol is 40:60 to 5:95, and particularly 30:70 to.
It is preferably within the range of 10:90. The amount of the medium used is 50 to 50 per 100 parts by weight of the polymerizable monomer.
It is preferably in the range of 00 parts by weight, particularly 500 to 2500 parts by weight.

As the dispersion stabilizer for stabilizing the dispersibility of the polymer in the medium, for example, polyacrylic acid, polyacrylic acid salt, polymethacrylic acid, polymethacrylic acid salt,
(Meth) acrylic acid- (meth) acrylic acid ester copolymer, acrylic acid-vinyl ether copolymer, methacrylic acid-styrene copolymer, carboxymethyl cellulose, poly (hydroxystearic acid-g-methyl methacrylate-co- (Methacrylic acid) copolymer, poly (ethylene oxide), polyacrylamide, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose,
Examples thereof include polyvinyl alcohol. Further, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants and the like can also be used. The amount of the dispersion stabilizer used is 0.
It is in the range of 1 to 30% by weight, preferably 1 to 10% by weight.

In the spray-drying method, as a solvent for dissolving the above-mentioned components, a solvent capable of dissolving a fixing resin is preferably adopted from various conventionally known organic solvents. The solid content concentration of the spray-dried solution may be similar to the conventional one.

[0073]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples. Example 1 <Production of Spherical Toner> 100 g of grafted carbon black (styrene content 40% by weight) produced by treating carbon black with a styrene monomer was mixed with each of the following components in a high-speed stirrer (Tokuki Kika Kogyo Co., Ltd.). Made of TK
With a homomixer) at a rotation speed of 100 rpm for 10 minutes,
The monomer phase was prepared by stirring.

Component (g) -Polymerizable monomer Styrene 400 Ethyl acrylate 120-Crosslinking agent Divinylbenzene 0.5-Polymerization initiator benzoyl peroxide 12-Polymerization regulator t-dodecyl mercaptan 1-Charge control agent Bontron S-34 5 Next, the above-mentioned monomer phase was added to 2000 as an aqueous dispersion medium.
g of ion-exchanged water and 65 g of polyvinyl alcohol as a dispersion stabilizer, and the mixture is agitated for 30 minutes at a rotation speed of 10,000 rpm with the high speed agitator described above to obtain an average particle diameter of 10 μm. A suspension of was prepared.

Next, this suspension was transferred to a 3 liter separable flask equipped with a stirrer, a nitrogen introducing tube and a condenser, and heated to 75 ° C. with stirring under a nitrogen atmosphere to carry out a polymerization reaction for 8 hours. After that, the obtained polymer particles were separated by filtration. Then, the polymer particles are washed with purified water several times,
The toner particles were dried to obtain toner particles. When the average particle size of the obtained toner particles was measured with a Coulter counter, it was 1
It was 0 μm.

When the obtained toner particles t were observed with an electron microscope, it was confirmed that they were substantially spherical, as shown in FIG. 2 (a). <Modification of Toner Particles> 100 g of the spherical toner particles obtained above is mixed with 50 g of sodium chloride powder (particle diameter of about 1 μm) as fine particles of an inorganic substance, and 200 kg / cm ² using a hydraulic press. The pressure was applied under the conditions described above to agglomerate.

Next, this aggregate was put into a large amount of water,
After stirring with a household mixer to dissolve and remove sodium chloride to decompose it, the mixture was filtered, washed with ion-exchanged water, and dried to obtain a deformed electrophotographic toner. When the obtained electrophotographic toner T was observed with an electron microscope, it was confirmed that the toner was deformed as shown in FIG. 2 (b).

The particle size distribution of the obtained electrophotographic toner was measured with a Coulter counter.
As indicated by the broken line in Fig. 5, it was confirmed that the particle size distribution was almost the same as that before the deforming (shown by the solid line in the figure), and that the particle size distribution was not changed by the deforming treatment. Example 2 The following components were mixed with a high-speed stirrer (TK manufactured by Tokushu Kika Kogyo Co., Ltd.
With a homomixer) at a rotation speed of 100 rpm for 10 minutes,
The monomer phase was prepared by stirring.

Component (g) -Polymerizable Monomer Styrene 500 2-Ethylhexyl Methacrylate 120-Crosslinker Divinylbenzene 1-Colorant Carbon Black 30-Coupling Agent Methyltrimethoxysilane 3-Polymerization Initiator 2, 2'-azobisisobutyronitrile 12-Polymerization regulator t-dodecyl mercaptan 3-Charge control agent azo oil black 5 Next, the above-mentioned monomer phase was added as an aqueous dispersion medium to 2000.
g of ion-exchanged water and 40 g of silica sol (particle diameter of about 0.2 μm) as fine particles of an inorganic substance, and mixed with a high-speed stirrer as described above at a rotation speed of 10,000 r.p.
Stirring was carried out for 30 minutes at m. to prepare a suspension having an average particle diameter of droplets of 10 μm.

Next, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1, the reaction solution was separated using a Buchner funnel and a suction bottle, and dried to obtain toner particles.
The average particle size of the obtained toner particles was measured with a Coulter counter, and it was 10 μm. Further, when the obtained toner particles were observed with an electron microscope, it was confirmed that the toner particles were substantially spherical and that many silica fine particles were attached to the surface thereof.

<Modification of Toner Particles> The spherical toner particles obtained as described above are subjected to 200 kg / cm 2 by using a hydraulic press.
Pressure was applied under the condition of ² to cause aggregation. Next, 4
It is put into an aqueous solution of sodium hydroxide of N and decomposed by dissolving and removing the silica fine particles by stirring with a household mixer, and then filtered, washed with ion-exchanged water, dried and deformed. The obtained electrophotographic toner was obtained.

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed in the same manner as in Example 1. Further, the particle size distribution of the obtained electrophotographic toner was measured in the same manner as in Example 1, and it was confirmed that there was almost no change from that before the deformation. Comparative Example 1 After coarsely pulverizing an aggregate of toner particles and sodium chloride powder obtained by deforming the toner particles of Example 1, a supersonic jet mill (IDS2 type manufactured by Nippon Pneumatic Mfg. Co., Ltd.)
Was disintegrated to a particle size of about 10 μm to obtain a modified electrophotographic toner.

The particle size distribution of the obtained electrophotographic toner is
When measured in the same manner as in Example 1, as shown by the broken line in FIG. 4, the particle size distribution before deformation was greatly deviated (shown by the solid line in the same figure), and particularly the distribution of small particle size components increased. From this, it was confirmed that the toner particles themselves were crushed by the forced crushing of the aggregates. Comparative Example 2 The spherical toner particles obtained in the production of the spherical toner of Example 1 before being modified were used as Comparative Example 2 as they were.

The electrophotographic toners prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were mixed with a ferrite carrier to prepare a two-component developer having a toner concentration of 3% by weight. The agent was used in an electrostatic copying machine [Model DC-1205 manufactured by Mita Kogyo Co., Ltd.] to evaluate the cleaning property and the image forming property of the electrophotographic toner by the following test methods.

Cleaning Property Test As shown in FIG. 5, a sheet of A3 size blank 1 to which a strip 2 having a width of 30 mm and a Munsell value of N2.0 is pasted is used as an original for transfer to the electrostatic copying machine. Without supplying the paper, the copying operation is performed under the normal temperature and normal temperature environment of 20 ° C. and the humidity of 65% RH and the high temperature and high humidity environment of the temperature of 35 ° C. and the humidity of 85% RH, and the cleaning process is completed. Before that, the switch was turned off to stop the copying machine, and the photoconductor drum was taken out.

Next, as shown in FIG. 6, the photosensitive drum 3
In the toner image corresponding to the above-mentioned original on the surface of, the rotation direction of the photoconductor drum 3 (indicated by a white arrow in the figure) from the cleaning blade contact position shown by the dashed line in the figure in the portion 4 corresponding to the strip 2. The cellophane adhesive tape was attached to the surface of the portion 4a (shown by the broken line) that was cleaned by the cleaning blade on the downstream side of FIG.

Next, after the above-mentioned cellophane adhesive tape was peeled from the surface of the photosensitive drum 3 and attached to the surface of a white paper, the density thereof was measured by a reflection densitometer (TC-6 manufactured by Tokyo Denshoku Co., Ltd.).
The cleaning property was evaluated by measuring using D). The density is 0.10 to 0.14 when no toner remains on the surface of the photosensitive drum, and the density is 0.2.
When the above is reached, it is determined that the toner remains.

The results are shown in Table 1.

[0089]

[Table 1]

As is clear from the results shown in Table 1, the non-deformed spherical electrophotographic toner of Comparative Example 2 has a very poor cleaning property and a large amount remains on the surface of the photosensitive drum. all right. On the other hand, it was found that the deformed electrophotographic toners of Examples 1 and 2 and Comparative Example 1 were excellent in cleaning property under any environment and hardly remained on the surface of the photoconductor drum.

Image Forming Characteristic Test Using the electrophotographic toners of Examples 1 and 2 and Comparative Example 1 in which the results of the above cleaning property test were good, an electrostatic copying machine was used to transfer paper. The same original used in the cleaning test is supplied at a temperature of 20 ° C. and a humidity of 65% RH at room temperature in a normal humidity environment, and at a temperature of 35 ° C. and a humidity of 85% RH in a high humidity environment. After copying, the formed image was visually evaluated. Further, regarding the formed images formed by using the electrophotographic toners of Examples 1 and 2, the image density of the portion corresponding to the strip portion having the Munsell value N2.0 of the original document was measured using the reflection densitometer. It was measured.

The results are shown in Table 2.

[0093]

[Table 2]

As is clear from the results shown in Table 2, Comparative Example 1
When the electrophotographic toner of No. 1 was used, a good image was obtained under normal temperature and normal humidity environment, but in the high temperature and high humidity environment, remarkable fog was observed on the image, and a good image was obtained. There wasn't. In contrast, when the electrophotographic toners of Examples 1 and 2 were used, good images were obtained under any environment. The image density of the portion of the formed image corresponding to the strip portion having the Munsell value N2.0 is about 1.2 in the case of the electrophotographic toner of Example 1, and is in the case of the electrophotographic toner of Example 2. Was about 1.3, and a practically sufficient concentration was obtained.

Example 3 <Production of Spherical Toner> 100 g of grafted carbon black (styrene content 40% by weight) produced by treating carbon black with a styrene monomer was mixed with the following components in a high-speed stirrer (special machine). TK manufactured by Chemical Industry
With a homomixer) at a rotation speed of 100 rpm for 10 minutes,
The monomer phase was prepared by stirring.

Component (g) -Polymerizable monomer Styrene 400 Butyl acrylate 120-Crosslinker divinylbenzene 1-Polymerization initiator benzoyl peroxide 12-Polymerization regulator t-dodecyl mercaptan 1-Charge control agent Bontron S- 34 5 Next, the above-mentioned monomer phase was added to 600 g as an aqueous dispersion medium.
Ion-exchanged water, 65 g of hydroxyapatite as an inorganic substance, and 100 g of concentrated hydrochloric acid (11N) were mixed, and the rotation speed was 10,000 using the high-speed stirrer described above.
The monomer phase was suspended in a droplet form by stirring at rpm, and hydroxyapatite was dissolved in the aqueous dispersion medium. Then, when 3 minutes have passed after the start of stirring, 400 g of a 4N sodium hydroxide aqueous solution was added while continuing stirring to precipitate hydroxyapatite on the surface of the droplets, and then the mixture was stirred for another 30 minutes to prepare a liquid. The average particle size of the drops is 10
A μm suspension was made.

Next, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1, the reaction solution was separated using a Buchner funnel and a suction bottle, and dried to obtain toner particles.
The average particle size of the obtained toner particles was measured with a Coulter counter, and it was 10 μm. Further, when the obtained toner particles were observed with an electron microscope, it was confirmed that they were substantially spherical and that hydroxyapatite was uniformly deposited on the surface thereof.

<Modification of Toner Particles> The spherical toner particles obtained above are subjected to 200 kg / cm by using a hydraulic press.
Pressurize under the condition of ² to agglomerate, and then agglomerate 0.5N
Electrolyzed into a dilute hydrochloric acid after being placed in dilute hydrochloric acid and stirred with a household mixer to dissolve and remove hydroxyapatite, and then decomposed, filtered, washed with ion-exchanged water, and dried. To obtain toner for use.

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed as in Example 1. Further, the particle size distribution of the obtained electrophotographic toner was measured in the same manner as in Example 1, and FIG.
As indicated by the broken line in Fig. 5, it was confirmed that the particle size distribution was almost the same as that before the deforming (shown by the solid line in the figure), and that the particle size distribution was not changed by the deforming treatment.

Comparative Example 3 The monomer phase prepared in Example 3 was mixed with 1000 g of ion-exchanged water as an aqueous dispersion medium and 30 g of polyvinyl alcohol as a dispersion stabilizer, and the mixture was mixed with the high-speed stirrer described above. The suspension was stirred at a rotation speed of 10,000 rpm for 30 minutes to prepare a suspension having an average particle diameter of droplets of 10 μm.

Then, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1, the reaction solution was separated using a Buchner funnel and a suction bottle, and dried to obtain toner particles.
The average particle size of the obtained toner particles was measured with a Coulter counter, and it was 10 μm. Next, 100 g of the toner particles are mixed with 13 g of hydroxyapatite powder (particle diameter of about 1 μm), and a hydraulic press is used to
After pressure is applied under the condition of 200 kg / cm ² to agglomerate, the agglomerate is coarsely crushed, and then the particle size becomes about 10 μm using a supersonic jet mill (IDS2 type manufactured by Nippon Pneumatic Mfg. Co., Ltd.). To obtain a deformed electrophotographic toner.

The particle size distribution of the obtained electrophotographic toner is
When measured in the same manner as in Example 1, as shown by the broken line in FIG. 8, the particle size distribution before deformation was largely deviated (shown by the solid line in the same figure), and particularly the distribution of small particle size components increased. From this, it was confirmed that the toner particles themselves were crushed by the forced crushing of the aggregates. The electrophotographic toners prepared in Example 3 and Comparative Example 3 were mixed with a ferrite carrier to prepare a two-component developer having a toner concentration of 3% by weight. Similarly, the cleaning property and the image forming property were evaluated. The cleaning property results are shown in Table 3, and the image forming property results are shown in Table 4.

[0103]

[Table 3]

As is clear from the results of Table 3, Example 3
It was also found that the electrophotographic toner of Comparative Example 3 has excellent cleaning properties under any environment and hardly remains on the surface of the photosensitive drum.

[0105]

[Table 4]

As is clear from the results of Table 4, Comparative Example 3
When the electrophotographic toner of No. 1 was used, a good image was obtained under normal temperature and normal humidity environment, but in the high temperature and high humidity environment, remarkable fog was observed on the image, and a good image was obtained. There wasn't. On the other hand, when the electrophotographic toner of Example 3 was used, good images were obtained under any environment.
In the formed image, the image density of the portion corresponding to the strip having the Munsell value N2.0 is about 1.2 in the case of the electrophotographic toner of Example 3, and a density sufficient for practical use is obtained. It was

Example 4 <Production of Spherical Toner> 100 g of grafted carbon black (styrene content 40% by weight) produced by treating carbon black with a styrene monomer was mixed with the following components in a high-speed stirrer (special machine). TK manufactured by Chemical Industry
With a homomixer) at a rotation speed of 100 rpm for 10 minutes,
The monomer phase was prepared by stirring.

Component (g) -Polymerizable monomer Styrene 400 Butyl acrylate 120-Crosslinking agent Divinylbenzene 0.5-Polymerization initiator benzoyl peroxide 12-Polymerization regulator t-dodecyl mercaptan 1-Charge control agent Bontron S-34 5 Next, the above-mentioned monomer phase was added to 2000 as an aqueous dispersion medium.
g of ion-exchanged water and 65 g of polyvinyl alcohol as a dispersion stabilizer, and the mixture is agitated for 30 minutes at a rotation speed of 10,000 rpm with the high speed agitator described above to obtain an average particle diameter of 10 μm. A suspension of was prepared.

Next, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1 to form toner particles, and then while stirring was continued, hydroxyapatite 62 as an inorganic substance was added.
g and 100 g of concentrated hydrochloric acid (11N) were added to dissolve hydroxyapatite in the aqueous dispersion medium. Then, when the hydroxyapatite was dissolved, 400 g of a 4N sodium hydroxide aqueous solution was added while continuing stirring, and the stirring was further continued for 5 minutes to deposit hydroxyapatite on the surfaces of the toner particles.

Thereafter, the reaction liquid was separated using a Buchner funnel and a suction bottle and dried to obtain toner particles. The average particle size of the obtained toner particles was measured with a Coulter counter, and it was 10 μm. Further, when the obtained toner particles are observed with an electron microscope, they are almost spherical,
Moreover, it was confirmed that hydroxyapatite was uniformly deposited on the surface.

<Modification of Toner Particles> The spherical toner particles obtained above are heated to 80 ° C. and pressurized under the condition of 1 kg / cm ² to be agglomerated, and then the agglomerates are diluted with 0.5N dilute hydrochloric acid. After dissolving it by stirring with a household mixer to dissolve and remove hydroxyapatite, it is separated by filtration, washed with ion-exchanged water, and dried to obtain a deformed electrophotographic toner. Obtained.

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed in the same manner as in Example 1. Further, the particle size distribution of the obtained electrophotographic toner was measured in the same manner as in Example 1, and FIG.
As indicated by the broken line in Fig. 5, it was confirmed that the particle size distribution was almost the same as that before the deforming (shown by the solid line in the figure), and that the particle size distribution was not changed by the deforming treatment.

Comparative Example 4 62 g of hydroxyapatite powder (particle diameter of about 1 μm) as inorganic fine particles was added to the suspension at the time when the polymerization reaction was completed in Example 4, and the mixture was sufficiently stirred, and then the reaction solution was added. The particles were separated using a Buchner funnel and a suction bottle and dried to obtain toner particles.

The average particle diameter of the obtained toner particles was measured with a Coulter counter and found to be 10 μm. Further, when the obtained toner particles were observed with an electron microscope, it was confirmed that the toner particles were substantially spherical and that the hydroxyapatite powder was adsorbed on the surface thereof. Next, the toner particles are heated to 80 ° C. and pressurized under the condition of 1 kg / cm ² to aggregate the particles, and the aggregate is coarsely crushed, and then supersonic jet mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.). IDS
2 type) was crushed to a particle size of about 10 μm to obtain a deformed electrophotographic toner.

The particle size distribution of the obtained electrophotographic toner is
When measured in the same manner as in Example 1, as shown by the broken line in FIG. 10, the particle size distribution before deformation (shown by the solid line in the same figure)
It was confirmed that the toner particles themselves were crushed by the forced crushing of the agglomerates because the distribution of the small particle size component increased especially. Further, since the distribution of the large particle size component was slightly increased, it was also confirmed that the toner particles were fused to each other.

The electrophotographic toners prepared in Example 4 and Comparative Example 4 were mixed with a ferrite carrier to prepare a two-component developer having a toner concentration of 3% by weight, and this two-component developer was used. The cleaning property and the image forming property were evaluated in the same manner as described above. The results of the cleaning property are shown in Table 5, and the results of the image forming characteristics are shown in Table 6.

[0117]

[Table 5]

As is clear from the results of Table 5, Example 4
It was also found that the electrophotographic toner of Comparative Example 4 has excellent cleaning properties under any environment and hardly remains on the surface of the photosensitive drum.

[0119]

[Table 6]

As is clear from the results of Table 6, Comparative Example 4
When the electrophotographic toner of No. 1 was used, a good image was obtained under normal temperature and normal humidity environment, but in the high temperature and high humidity environment, remarkable fog was observed on the image, and a good image was obtained. There wasn't. On the other hand, when the electrophotographic toner of Example 4 was used, good images were obtained under any environment.
In the formed image, the image density of the portion corresponding to the strip having the Munsell value N2.0 is about 1.3 in the case of the electrophotographic toner of Example 4, and a density sufficient for practical use is obtained. It was

Example 5 The following components were mixed in a high-speed stirrer (TK manufactured by Tokushu Kika Kogyo Co., Ltd.).
With a homomixer) at a rotation speed of 100 rpm for 10 minutes,
The monomer phase was prepared by stirring. Component (g) -Polymerizable monomer Styrene 500 2-Ethylhexyl methacrylate 120-Crosslinker divinylbenzene 1-Colorant carbon black 30-Coupling agent methyltrimethoxysilane 3-Polymerization initiator benzoyl peroxide 12- Polymerization modifier t-dodecyl mercaptan 1 Charge control agent Azo oil black 5 Next, the above monomer phase was added to 2000 as an aqueous dispersion medium.
g of ion-exchanged water, 40 g of silica sol (particle diameter of about 0.2 μm) as fine particles of inorganic substance, and 0.0 of sodium dodecylbenzenesulfonate as a dispersion stabilizer.
The suspension was mixed with 2 g and stirred for 30 minutes at a rotation speed of 10000 rpm with the above-mentioned high-speed stirrer to prepare a suspension having an average particle diameter of droplets of 10 μm.

Next, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1 to form toner particles, and the reaction solution was concentrated using a Buchner funnel and a suction bottle to obtain a water content of 6
A toner cake of 5% by weight was obtained. The glass transition temperature (Tg) of the resin portion of the obtained toner cake was about 72 ° C. (result of differential scanning calorimetry).

When the average particle size of the toner particles contained in the toner cake was measured with a Coulter counter,
It was 10 μm. Further, when the obtained toner particles were observed with an electron microscope, it was confirmed that the toner particles were substantially spherical and that many silica fine particles were attached to the surface thereof. <Modification of Toner Particles> The toner cake obtained above is placed in an oven equipped with a ventilation mechanism, heat-treated at 100 ° C. for 1 hour to agglomerate, and then this agglomerate is put into a 4N sodium hydroxide aqueous solution. Then, the fine silica particles are dissolved by stirring with a household mixer to dissolve and remove the fine particles, and then separated by filtration, washed with ion-exchanged water, and dried to obtain a modified electrophotographic toner. .

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed as in Example 1. The particle size distribution of the obtained electrophotographic toner was measured in the same manner as in Example 1.
As indicated by the broken line in 1, the particle size distribution was almost the same as the particle size distribution before deformation (shown by the solid line in the figure), and it was confirmed that the particle size distribution was not changed by the deformation treatment.

Comparative Example 5 <Production of Spherical Toner> The monomer phase prepared in Example 3 was mixed with 1000 g of ion-exchanged water as an aqueous dispersion medium and 30 g of polyvinyl alcohol as a dispersion stabilizer.
Mix with and use the high-speed stirrer described above to rotate at 1
The suspension was stirred at 0000 rpm for 30 minutes to prepare a suspension having a droplet average particle size of 10 μm.

Then, this suspension was subjected to a polymerization reaction under the same conditions as in Example 1, the reaction solution was separated using a Buchner funnel and a suction bottle, and dried to obtain toner particles.
The average particle size of the obtained toner particles was measured with a Coulter counter, and it was 10 μm. The glass transition temperature (Tg) of the obtained toner particles was about 70 ° C. (result of differential scanning calorimetry).

<Modification of Toner Particles> The toner particles obtained above are moistened with water to have a water content of 65% by weight, which is placed in an oven equipped with a ventilation mechanism and heat-treated at 80 ° C. for 1 hour. After aggregating, the agglomerates are coarsely crushed, and then crushed using a supersonic jet mill (IDS2 type manufactured by Nippon Pneumatic Mfg. Co., Ltd.) until the particle size becomes about 10 μm, and then deformed. The obtained electrophotographic toner was obtained.

The particle size distribution of the obtained electrophotographic toner is
When measured in the same manner as in Example 1, as shown by the broken line in FIG. 12, the particle size distribution before deforming (shown by the solid line in the same figure)
It was confirmed that the toner particles themselves were crushed by the forced crushing of the agglomerates because the distribution of the small particle size component increased especially. Further, since the distribution of the large particle size component also increased, it was confirmed that the toner particles were fused to each other.

Comparative Example 6 1000 g of the toner particles produced in Comparative Example 5 was
The mixture was placed in a 0 mm cylinder, and a hydraulic press was used to agglomerate it at a pressure of 0.5 kg / cm ² for 30 seconds at room temperature, and then the agglomerates were crushed in the same manner as in Comparative Example 5. Observation of the disintegrated product with an electron microscope confirmed that agglomerates of a plurality of toner particles and spherical toner particles that were hardly deformed were mixed and could not be used as an electrophotographic toner. It was

The electrophotographic toners prepared in Example 5 and Comparative Example 5 were mixed with a ferrite carrier to prepare a two-component developer having a toner concentration of 3% by weight, and this two-component developer was used. The cleaning property and the image forming property were evaluated in the same manner as described above. The results of the cleaning property are shown in Table 7, and the results of the image forming characteristics are shown in Table 8.

[0131]

[Table 7]

As is clear from the results in Table 7, Example 5
It was also found that the electrophotographic toner of Comparative Example 5 has excellent cleaning properties under any environment and hardly remains on the surface of the photosensitive drum.

[0133]

[Table 8]

As is clear from the results of Table 8, Comparative Example 5
When the electrophotographic toner of No. 1 was used, a good image was obtained under normal temperature and normal humidity environment, but in the high temperature and high humidity environment, remarkable fog was observed on the image, and a good image was obtained. There wasn't. On the other hand, when the electrophotographic toner of Example 5 was used, good images were obtained under any environment.
In the formed image, the image density of the portion corresponding to the strip having the Munsell value N2.0 is about 1.3 in the case of the electrophotographic toner of Example 4, and a density sufficient for practical use is obtained. It was

Examples 6 to 8 The water content of the toner cake was 43% by weight (Example 6), 7%.
An electrophotographic toner was produced in the same manner as in Example 5, except that the content was set to be 0% by weight (Example 7) and 0% by weight (Example 8). Then, the electrophotographic toners of Examples 6 to 8 were mixed with a ferrite carrier to prepare a two-component developer having a toner concentration of 3% by weight, and the two-component developer was used in the same manner as described above. Temperature 20 ℃, humidity 65
% RH was evaluated for cleanability under normal temperature and normal humidity environment.

Further, electron micrographs of the electrophotographic toners of the above respective Examples and Example 5 were taken, the major axis and the minor axis of about 100 toner particles were measured, and the average value of the ratios thereof was calculated. Deformed degree. The results are shown in Table 9 together with the results of the cleaning property under the normal temperature and normal humidity environment of Example 5 described above.
Shown in.

[0137]

[Table 9]

As is clear from the results shown in Table 9, the higher the water content of the toner cake, the more marked the degree of deformation of the electrophotographic toner produced, and the better the cleaning property. In particular, the electrophotographic toners of Examples 5 and 6 in which the water content of the toner cake was 43% by weight or more were remarkably excellent in cleaning property, and were all cleaned.

Example 9 <Production of Spherical Toner> 2.5 g of a methacrylic acid-methyl acrylate copolymer as a dispersion stabilizer was added to 200 g of ethanol and 40 g of purified water as a dispersion medium for dispersion polymerization. After being dissolved, the following components were dissolved.

Component (g) -Polymerizable Monomer Styrene 60-Polymerization Initiator Azobisisovaleronitrile 2.5-Colorant Oil-soluble Red Dye 1.8 Next, the above solution is stirred with a nitrogen introducing pipe. And transfer to a 1 liter separable flask equipped with a condenser, and under a nitrogen atmosphere, stirring at a rotation speed of 40 rpm and 50
The mixture was heated to 0 ° C. and polymerized for 200 minutes. Then, while continuing stirring, a micro feeder (manufactured by Furue Science Co., Ltd.) was used in the flask at a rate of 0.1 ml / min for 10
Water was added dropwise for 00 minutes.

After the completion of dropping of water, the dispersion was observed with an optical microscope. As a result, it was confirmed that monodisperse red spherical toner particles having a uniform particle size of about 7 μm were produced. Next, 20 g of barium sulfate powder (particle size: about 1 μm) as fine particles of an inorganic substance was added to the above-mentioned dispersion liquid, which was then separated using a Buchner funnel and a suction bottle and dried to obtain a toner having a water content of 45% by weight. Got a cake

The glass transition temperature (Tg) of the resin portion of the obtained toner cake is about 69 ° C. (result of differential scanning calorimetry)
Met. <Modification of Toner Particles> The toner cake obtained above is placed in an oven equipped with a ventilation mechanism, heat-treated at 75 ° C. for 3 hours to aggregate, and then the aggregate is placed in 0.5N dilute hydrochloric acid. , Decomposed by dissolving and removing barium sulfate by stirring with a household mixer, then filtering,
It was washed with ion-exchanged water and dried to obtain a deformed red electrophotographic toner.

When the obtained electrophotographic toner T was observed with an electron microscope, it was confirmed that the toner was deformed as shown in FIG. Further, when the particle size distribution of the obtained electrophotographic toner was measured by a Coulter counter, as shown in FIG. 14, there was a tendency of monodispersion with a uniform particle size of about 7 μm, and the particle size distribution was changed by the deforming treatment. It was confirmed that there was no change.

Example 10 3 g of polymethacrylic acid as a dispersion stabilizer was dissolved in 240 g of butanol as a dispersion medium for dispersion polymerization and 40 g of purified water, and then the following components were dissolved. Component (g) -Polymerizable monomer Styrene 45 Methyl methacrylate 15 Nitrostyrene 0.1-Polymerization initiator azobisisobutyronitrile 2.5 Next, stirrer, nitrogen inlet tube and condenser with the above solution. Transfer to a 1 liter separable flask attached, and stir at a rotation speed of 40 rpm under a nitrogen atmosphere.
The mixture was heated to 0 ° C. and polymerized for 8 hours.

After completion of the reaction, the reaction solution is filtered to give about 5 μm.
Monodispersed uncolored spherical resin particles having a uniform particle size were obtained. Next, 50 g of the above resin particles are dispersed in 1 liter of water together with 6 g of a quinone blue disperse dye and 40 g of silica sol (particle diameter of about 0.2 μm) as fine particles of an inorganic substance, and the mixture is dispersed in an autoclave at 140 ° C. The dyeing treatment was carried out for 1 hour.

The resin particles after dyeing were observed with an optical microscope.
However, it was confirmed that it was dyed blue. Next
Using a Buchner wax and suction bottle,
Separated and dried to obtain a toner cake. <Modification of toner particles> Toner cake obtained above
Using a hydraulic press at 70 ℃, 100kg / cm ² Article
Depending on the situation, heat and pressurize to agglomerate.
Put it into the sodium hydroxide aqueous solution of
Dissolve and remove silica sol by stirring using
After unraveling, it is filtered off, washed with deionized water and dried.
Thus, a deformed blue electrophotographic toner was obtained.

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed as in Example 9. Further, the particle size distribution of the obtained electrophotographic toner was measured in the same manner as in Example 9 and found to be about 5
A tendency of monodispersion with uniform particle size was shown in μm, and it was confirmed that the particle size distribution did not change due to the modification treatment.

Comparative Example 7 The spherical toner particles obtained in the production of the spherical toner of Example 9 before being modified were used as Comparative Example 7 as they were. Comparative Example 8 An electrophotographic toner was obtained in the same manner as in Example 9, except that the heat treatment temperature of the toner cake in the oven was set to 65 ° C., which was lower than the glass transition temperature of the resin portion, in the same manner as in Example 9. When observed with an electron microscope, it was confirmed that they were almost spherical and were not deformed.

The electrophotographic toners of Examples 9 and 10 and Comparative Examples 7 and 8 were each mixed with a ferrite carrier to have a toner concentration of 3% by weight (Example 10 is 2.3% by weight).
Of the two-component developer, and using this two-component developer,
In the same manner as described above, the cleaning property under the normal temperature and normal temperature environment of the temperature of 20 ° C. and the humidity of 65% RH was evaluated. The image forming characteristics of Examples 9 and 10 were also evaluated.

The results are shown in Table 10.

[0151]

[Table 10]

As is clear from the results shown in Table 10, the electrophotographic toners of Comparative Examples 7 and 8 had very poor cleaning properties and were found to remain in large amounts on the surface of the photosensitive drum. On the other hand, it was found that the deformed electrophotographic toners of Examples 9 and 10 were excellent in cleaning property and hardly remained on the surface of the photosensitive drum. The image density of the portion of the formed image corresponding to the strip portion having the Munsell value N2.0 is 1.02 in the case of the electrophotographic toner of Example 9, and is 1.02 in the case of the electrophotographic toner of Example 10. It was 1.1, and a practically sufficient concentration was obtained.

Example 11 <Production of Spherical Toner> The following components were sufficiently mixed and dispersed using an ultrasonic disperser to prepare a spray liquid for spray drying. Component (g) -Fixing resin Styrene butyl acrylate copolymer 400-Colorant carbon black 20-Charge control agent Bontron S-345-Solvent Toluene 8000 A spray drying device (Okawara Kakohki Co., Ltd.) CL-8) was spray-dried to obtain spherical toner particles having an average particle diameter of 10 μm.

<Modification of Toner Particles> 100 g of the spherical toner particles obtained above is mixed with 40 g of sodium chloride powder (particle diameter of about 1 μm) as fine particles of an inorganic material, and 200 kg is obtained by using a hydraulic press. A pressure was applied under the condition of / cm ² to agglomerate. Next, this aggregate is put into a large amount of water, and the mixture is stirred by using a household mixer to dissolve and remove sodium chloride, and then decomposed, followed by filtration, washing with ion-exchanged water, and drying, A modified electrophotographic toner was obtained.

When the obtained electrophotographic toner was observed with an electron microscope, it was confirmed that the toner was deformed as in Example 1. Further, the particle size distribution of the obtained electrophotographic toner was measured by a Coulter counter, and as shown by the broken line in FIG. 15, it was almost the same as the particle size distribution before modification (shown by the solid line in the figure), It was confirmed that the particle size distribution did not change due to the chemical treatment.

[0156]

As described above in detail, the electrophotographic toner of the present invention has an extremely narrow particle size distribution and can be made into a small particle size, has excellent fluidity, and has cleaning properties with a cleaning blade. It is excellent. Therefore, the electrophotographic toner of the present invention has extremely excellent characteristics in terms of charging characteristics and image quality. Further, since the electrophotographic toner of the present invention does not require any classification, the yield is high and the productivity is extremely excellent.

Further, according to the method for producing a toner for electrophotography of the present invention, the advantages of spherical toner particles that the particle size distribution is narrow and the particle size can be made small and that the flowability is excellent are maintained as they are, In addition, it becomes possible to manufacture an electrophotographic toner having excellent cleaning properties with a cleaning blade. Further, since the electrophotographic toner manufactured by the above manufacturing method does not require any classification, the yield is high and the productivity is excellent. Moreover, according to the above-mentioned manufacturing method, there is an advantage that the degree of deformation can be freely adjusted by controlling the degree of aggregation. Further, in the above-mentioned manufacturing method, there is an advantage that energy cost can be reduced because a mechanical crushing means such as a jet mill is unnecessary.

[Brief description of drawings]

FIG. 1A to FIG. 1C are diagrams schematically explaining a process of heating spherical toner particles in the presence of water to aggregate and deform them.

FIG. 2 (a) is a front view showing the appearance of spherical toner particles produced in Example 1 of the present invention, and FIG. 2 (b).
FIG. 4 is a front view showing the appearance of an electrophotographic toner obtained by deforming the spherical toner particles.

FIG. 3 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being modified in Example 1.

FIG. 4 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being deformed in Comparative Example 1 of the present invention.

FIG. 5 is a front view of a document image used in an electrostatic copying machine to evaluate the cleaning properties of the electrophotographic toners manufactured in Examples and Comparative Examples of the present invention.

FIG. 6 is a perspective view showing a photosensitive drum taken out from an electrostatic copying machine in order to evaluate the cleaning property of the electrophotographic toner using the original image.

FIG. 7 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being modified in Example 3 of the present invention.

FIG. 8 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being deformed in Comparative Example 3 of the present invention.

FIG. 9 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being modified in Example 4 of the present invention.

FIG. 10 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being deformed in Comparative Example 4 of the present invention.

FIG. 11 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being modified in Example 5 of the present invention.

FIG. 12 is a graph showing particle size distributions of spherical toner particles and electrophotographic toner after being deformed in Comparative Example 5 of the present invention.

FIG. 13 is a front view showing the external appearance of the electrophotographic toner manufactured in Example 9 of the present invention. is there.

FIG. 14 is a graph showing the particle size distribution of the electrophotographic toner in Example 9 described above.

FIG. 15 is a graph showing the particle size distribution of the electrophotographic toner in Example 11 of the present invention.

[Explanation of sign]

 T Electrophotographic toner t Toner particles

Claims (5)

[Claims] 1. A dispersion-polymerization method in which at least a polymerizable monomer is dissolved in a medium in which the polymerizable monomer is dissolved but the polymer is not dissolved The spherical toner particles are aggregated in a state where an inorganic substance is present between the toner particles so as to change the shape of the toner, and then the inorganic substance is chemically dissolved and removed to decompose the aggregate. Toner for electrophotography. 2. A step of degrading agglomerates by chemically dissolving and removing inorganic substances after aggregating substantially spherical toner particles in a state where an inorganic substance is present between the toner particles so as to deform the toner particles. A method of manufacturing an electrophotographic toner, comprising: 3. A substantially spherical toner particle produced by a suspension polymerization method, in which a monomer phase containing a polymerizable monomer is suspended and dispersed in an aqueous dispersion medium in the form of droplets for polymerization. In the above suspension polymerization method, an inorganic substance intervening between the toner particles during aggregation is chemically deposited on the surface of the monomer phase droplets suspended and dispersed in the aqueous dispersion medium from the aqueous dispersion medium. The method for producing a toner for electrophotography according to claim 2. 4. The method for producing an electrophotographic toner according to claim 2, wherein an inorganic substance interposed between the toner particles at the time of aggregation is chemically deposited from the solution on the surface of the toner particles. 5. The toner particles and the inorganic substance are mixed in the presence of water,
The method for producing an electrophotographic toner according to claim 2, wherein the resin portion of the toner particles is heated above the glass transition temperature to cause aggregation.