JP2002131977A - Electrostatic charge image developing toner, method for producing the same, electrostatic charge image developer, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having superior electrostatic charge characteristics and environmental dependence, a sharp grain size distribution and a small particle diameter, a method for producing the toner, a developer and a method for forming a color image having high image quality and high reliability. SOLUTION: The electrostatic charge image developing toner contains a bonding resin and a colorant and has 1-10 μm number average particle diameter D50n and a number average grain size distribution index GSDn of <=1.26. The total surfactant content of the toner particles is <=1.0 wt.% and the nonionic surfactant content is <=100 ppm. The bonding resin contains a self-dispersible resin containing a hydrophilic ethylenically unsaturated monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image in an electrophotographic method or an electrostatic recording method, and a method of manufacturing the same, an electrostatic image developer, and The present invention relates to an image forming method.

[0002]

2. Description of the Related Art Methods for visualizing image information via an electrostatic image, such as electrophotography, are currently used in various fields. In the electrophotography, an electrostatic image is formed on a photoreceptor in a charging / exposure process, the electrostatic image is developed with a developer containing toner, and visualized through a transfer and fixing process. The developer used here includes a two-component developer including a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone. The toner is usually produced by a kneading and pulverizing method in which a thermoplastic resin is melt-kneaded together with a pigment, a charge controlling agent, and a release agent such as wax, cooled, finely pulverized, and further classified. In order to improve the fluidity and the cleaning property of the toner, inorganic fine particles and organic fine particles may be added to the surface of the toner particles as needed.

On the other hand, in recent years, with the development of a highly information-oriented society, there has been an increasing demand for providing information documents constructed by various methods with images of higher image quality. Research is ongoing. In an image forming method using electrophotography,
This requirement is no exception, especially in electrophotography.
In order to realize a higher definition image in color image formation, it is required to reduce the diameter of the toner and achieve a sharp particle size distribution.

For example, in a digital full-color copying machine or a printer, a color image original is separated into colors by B (blue), R (red), and G (green) filters, and then separated into 20 to 70 μm corresponding to the original original. A latent image having a dot diameter is represented by Y (yellow), M (magenta),
Development is performed by a subtractive color mixing action using each of C (cyan) and Bk (black) developers. In this method, it is necessary to transfer a larger amount of developer compared to a conventional black-and-white machine, and it is necessary to correspond to a dot having a smaller diameter. It is increasingly important to ensure the properties, sharpness of the particle size distribution, and toner strength. Further, in consideration of speeding up and energy saving of these machines, further low-temperature fixability is required. For these reasons, a toner having a sharp particle size distribution and a small particle diameter is required.

However, in the conventional kneading and pulverizing method, the pulverization
In the classification operation, the number average particle diameter D _{50n which} can be provided economically and practically even in terms of _{reducing the} particle diameter is up to about 8 μm, and the number average particle diameter distribution index GSDn [( _D84n
/ D _16n ) ^1/2 ] of 1.30 or more, cannot produce a toner having a sharp particle size distribution. At present, methods for producing small particle size toners by various methods are being studied, but the kneading and pulverization method is merely a small particle size keeping the conventional particle size distribution, and it is difficult to improve the particle size distribution characteristics. there were. As a result, due to the presence of the fine powder side toner,
Carrier contamination, photoreceptor contamination, toner scattering and the like became remarkable, and it was difficult to achieve high image quality and high reliability at the same time.

For this reason, a method for producing a toner using various polymerization methods different from the kneading and pulverizing method has been studied. For example, a method for preparing a toner by a suspension polymerization method is disclosed in
JP-A-73276, JP-A-5-027476 and the like. However, the toner obtained by the suspension polymerization method cannot go out of the kneading and pulverizing method even if an attempt is made to control the particle size distribution of the toner, and in many cases, a further classification operation is required.

A method for preparing a toner using an emulsion polymerization method is described in JP-A-6-250439. In this method, a resin fine particle dispersion is prepared by emulsion polymerization using a surfactant, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared, and after mixing these dispersions, A surfactant having the opposite electric polarity to the surfactant is added, and the resin fine particles and the colorant are aggregated until a desired particle size is obtained.After that, the same polarity as that used for the adjustment of the resin fine particles is used. After adding a surfactant to stabilize the agglomerated particles to a desired particle size, the resin particles are heated to a temperature equal to or higher than the glass transition point of the resin fine particles and fused to produce a toner. The nonionic surfactant is added to ensure dispersion stability of the fine particles when preparing emulsion polymerization or a colorant dispersion.

The toner particles obtained by this method have an extremely sharp particle size distribution as compared with toner particles obtained by a polymerization method represented by a conventional suspension polymerization method. There is also an advantage that the toner particles can be adjusted to have irregular shapes from the viewpoint of cleaning properties. However, in the toner obtained by this emulsion polymerization method, the surfactant remaining in the toner significantly lowers the moisture absorption characteristics of the toner, resulting in poor charging of the toner, high environmental dependency, and a decrease in mechanical strength. This causes a serious problem in reliability and durability as a toner. In particular, since the nonionic surfactant has a strong affinity for the binder resin of the toner, it is difficult to remove it.

In the toner obtained by the above-mentioned emulsion polymerization method, 80% or more of the remaining surfactant is used for the step of aggregating the resin fine particles and the colorant particles, and the step of re-stabilizing the aggregated particles in the heat fusing step. Is added for the purpose. However, if the amount of the surfactant used in the aggregation step or the subsequent heat fusion step is reduced in order to reduce the amount of the surfactant remaining in the toner, the aggregation property is reduced and the particle size distribution is deteriorated. If aggregates are formed and the stability is insufficient in the heat fusing step, the particle size distribution deteriorates. Therefore, simply reducing the amount of the surfactant causes a serious problem in the production of the toner.

A monomer dispersion is prepared by emulsion polymerization of a monomer using a reactive emulsifier without using a surfactant in the presence of a coloring agent. A method has been proposed in which a coagulant comprising a trivalent or trivalent metal salt is added and coagulated to obtain toner particles (JP-A-63-205665). But,
In this method, a colorant is present when preparing a resin fine particle dispersion to produce colored resin fine particles.Depending on the type of the colorant, the colorant is uniformly dispersed in an emulsified dispersion system. In some cases, it is extremely difficult to uniformly contain a colorant in the toner. In such a case, it is necessary to manufacture the color toner necessary for forming a color image by a different method depending on the type of the colorant. When an image is formed with toner obtained by a different manufacturing method, if a trouble occurs, it becomes extremely difficult to find the cause. In addition, after emulsion polymerization is performed in the presence of a colorant to obtain colored resin fine particles, in order to obtain toner particles using a coagulant, a resin fine particle dispersion and a colorant dispersion are mixed to form a tetravalent flocculant. Is added and fused to produce a toner, the obtained toner has a wider particle size distribution, and it is difficult to obtain a toner having a sharp particle size distribution. Incidentally, the toner obtained by the above emulsion polymerization method has a number average particle size distribution index GSDn.
Is [(D _84n / D _16n) ^1/2] a larger value as 1.30 or more.

[0011]

DISCLOSURE OF THE INVENTION The present invention solves the above problems, has excellent charging characteristics and environmental dependency, and uniformly disperses the colorant in the toner regardless of the physical properties of the colorant. Capable of developing a small-particle-diameter electrostatic image developing toner having a sharp particle size distribution and a method for producing the same, an electrostatic image developer using the toner, and forming a high-quality and highly reliable color image To provide a way to do so.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, the present invention has made it possible to adopt the following structure. (1) In a toner for developing an electrostatic image containing a binder resin and a colorant, the toner has a number average particle diameter D _50n of 1 to 1.
0 μm, the number average particle size distribution index GSDn is 1.26 or less, the total surfactant content in the toner particles is 1.0% by weight or less, and the nonionic surfactant content is 100 ppm or less. Wherein the binder resin comprises a self-dispersible resin containing a hydrophilic ethylenically unsaturated monomer.

(2) The preferred range of the number average particle diameter D _50n is 3 to 8 μm, and the number average particle diameter distribution index GSDn
Is preferably 1.25 or less, and the total preferred range of the surfactant content is 0.5% by weight or less,
The preferred range of the nonionic surfactant content is 10 pp
m. or less, wherein the toner for developing an electrostatic image according to the above (1) is not more than m.

(3) The electrostatic image development as described in (1) or (2) above, wherein a part of the hydrophilic ethylenically unsaturated monomer is a monomer having an ionic dissociation group. For toner. (4) The toner for developing an electrostatic image as described in (3) above, wherein the ionic dissociating group of the monomer is a carboxyl group, a sulfonic group, a hydroxyl group, a methylolamide group, or an amino group.

(5) The toner for developing an electrostatic charge image according to (3) or (4), wherein at least a part of the monomer having an ionic dissociating group is a styrene derivative. (6) the styrene derivative is a sodium or potassium salt of styrenesulfonic acid,
(5) The toner for developing an electrostatic image as described in (5).

(7) At least a part of the monomer having an ionic dissociating group is at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and itaconic acid. The toner for developing electrostatic images according to any one of the above (4) to (6). (8) The electrostatic charge developing toner as described in any one of (1) to (7) above, wherein the toner particles include a release agent resin.

(9) A dispersion of fine particles of a self-dispersible resin containing a hydrophilic ethylenically unsaturated monomer and a dispersion of a colorant are mixed, and the mixture is divalent or more, preferably trivalent or more, more preferably 4 or more. After preparing the agglomerated particle dispersion by aggregating the resin fine particles and the colorant using an inorganic metal salt having a valence charge, heating the resin to a temperature equal to or higher than the glass transition point of the resin to fuse the agglomerated particles. The method for producing a toner for developing an electrostatic image according to any one of the above (1) to (8), wherein the toner particles are formed by heating.

(10) The self-dispersing resin fine particle dispersion is prepared by polymerizing a hydrophilic ethylenically unsaturated monomer by an emulsion polymerization method without using a surfactant.
The method for producing a toner for developing an electrostatic image according to the above. (11) An electrostatic image developer containing a toner and a carrier, wherein the electrostatic image developing toner according to any one of the above (1) to (8) is used. Agent.

(12) a step of forming an electrostatic latent image on an electrostatic charge carrier, a step of developing the electrostatic latent image with a developer on a developer carrier to form a toner image, and the toner image An image forming method including a step of transferring the developer onto a transfer body, wherein the electrostatic image developer according to (11) is used as the developer.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have provided a toner for developing an electrostatic image having a small particle diameter having excellent charging characteristics and environmental dependency, and having a sharp particle size distribution. The present inventors have intensively studied to provide an image forming method capable of forming a high-quality and high-reliability color image without scattering or fogging. As a result, it was found that the content of the surfactant remaining in the toner, particularly the content of the nonionic surfactant, greatly affected the chargeability of the toner and the deterioration of environmental dependency. The content is 1.0% by weight or less, and the content of the nonionic surfactant is 100 pp.
It has been found that by setting the value to m or less, stable charging performance and good environmental dependency can be achieved, leading to the present invention.

Therefore, in the present invention, a resin fine particle dispersion and a colorant dispersion are mixed, and an aggregating agent is added to the mixed liquid to form an aggregate, which is then heated to a temperature higher than the glass transition point of the resin. The adoption of the aggregation and fusion method in which the aggregated particles are fused by heating to form toner particles has enabled the production of toner particles having a small particle size and a sharp particle size distribution.
When a resin fine particle dispersion prepared by a conventional emulsion polymerization method is used, a surfactant of 80% in the obtained toner is used.
% Or more is derived from the resin fine particle dispersion, and in the present invention, a resin fine particle dispersion is prepared using a hydrophilic ethylenically unsaturated monomer without using a surfactant, By adding an aggregating agent of an inorganic metal salt having a charge of at least valence to form toner particles, the amount of surfactant remaining in the toner, particularly the amount of nonionic surfactant, is significantly reduced. Made it possible.

In the production method of the present invention, the surfactant may not be used in the step of preparing the fine resin particle dispersion, and the total content of the residual surfactant in the toner particles is 1.0% by weight or less. 100 pp nonionic surfactant content
m or less, and it was possible to provide a toner having stable charging performance and good environmental dependency. When the total amount of the residual surfactant exceeds 1% by weight,
The hygroscopic property deteriorates, causing a problem in the charging property. Further, even if the total amount of the residual surfactant is 1.0% by weight or less, if the amount of the nonionic surfactant in the residue exceeds 100 ppm, the charging characteristics are similarly adversely affected. The preferred range of the total amount of the residual surfactant is 0.5
% By weight and the preferred range of the amount of the nonionic surfactant is 10 ppm or less, and particularly preferably 0 ppm.

Examples of the surfactant include anionic surfactants having a negative charge in water, such as sulfates, sulfonates, phosphates, and soaps; amine salts, quaternary ammonium salts, and the like. Cationic surfactants and nonionic surfactants that have a positive charge in water are mainly polyethylene glycols, alkylphenol ethylene oxide adducts, polyhydric alcohols, etc. Refers to the substance to be applied.

The electrostatic image developing toner of the present invention preferably has a number average particle diameter D _50n of 1 to 10 μm and a number average particle size distribution index GSDn of 1.26 or less. GS
If Dn exceeds 1.26, image quality characteristics such as fine line reproducibility cannot be maintained. Also, the number average particle diameter D
_{When the thickness} exceeds ₅₀ μm and 10 μm, the resolution of the image decreases. When the number average particle diameter D _50n falls below 1 μm, the chargeability becomes insufficient. The more preferable range of the number average particle diameter D _50n is 3 to 8 μm, and the more preferable range of GSDn is 1.
25 or less.

By using a hydrophilic ethylenically unsaturated monomer, a dispersion of resin fine particles having self-dispersibility can be prepared without using a surfactant. In addition, when preparing an aggregated particle dispersion by mixing the resin fine particle dispersion, the colorant dispersion, and the release agent dispersion as required, an aggregating agent of a divalent or higher inorganic metal salt is used. Therefore, the use of a surfactant for aggregation can be avoided.

The above hydrophilic ethylenically unsaturated monomer is
Those having an ionic dissociation group such as a carboxyl group, a sulfonic acid group, and a hydroxyl group are preferred, and the polymer has self-dispersibility, thereby ensuring the stability of the resin fine particle dispersion and the stability of the aggregated particles. be able to.

The hydrophilic ethylenically unsaturated monomer used for the resin fine particles of the toner of the present invention can polymerize a binder resin without using a surfactant, and is self-dispersed in the binder resin. There is no particular limitation as long as the property can be imparted.
Then, it is sufficient that the self-dispersibility of the resin fine particles in the dispersion liquid after the formation of the resin fine particles and the dispersibility and stability in the aggregated particle dispersion liquid can be ensured.

The ethylenically unsaturated monomer components usable in the present invention include styrene, parachlorostyrene, α-
Styrenes such as methyl styrene; acrylic monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate , Methacrylic monomers such as lauryl methacrylate, 2-ethylhexyl methacrylate,
Vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; olefins such as ethylene, propylene and butadiene; Acrylic acid, methacrylic acid, maleic acid,
Examples include itaconic acid, carboxyethyl acrylate, styrene sulfonic acid, and metal salt monomers thereof, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, allyl alcohol, styrene sulfonic acid, and the like.

The ethylenically unsaturated monomer component having an ionic dissociating group includes styrene sulfonic acid and its metal salt, acrylic acid, methacrylic acid, maleic acid,
Itaconic acid and the like can be mentioned. More preferably, a sodium or potassium salt of styrenesulfonic acid having an ionic dissociating group and a benzene ring is most suitable. Use of a monomer having a benzene ring as described above has an advantage of increasing the water resistance of the toner. The ratio of copolymerization of the hydrophilic ethylenically unsaturated monomer of the present invention is 0.1% by weight of the whole polymer.
It is preferably from 0.05 to 5.0% by weight. If the amount is less than 0.05% by weight, sufficient stability cannot be imparted. If the amount is more than 5.0% by weight, the environmental dependency of the toner is undesirably increased.

In the production of the toner of the present invention, it is possible to add a release agent dispersion to the coagulation step to coagulate with the resin fine particles and the colorant and to fuse them into the toner. After aggregating the agent, it is also possible to add a release agent dispersion to adhere the release agent to the surface of the aggregated particles. Examples of the releasing agent used herein include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones, fatty acid amides such as oleamide, erucamide, ricinoleamide, and stearamide; carnauba wax And plant waxes such as rice wax, candelilla wax, wood wax, jojoba oil, etc .; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. And petroleum-based waxes and modified products thereof.

These waxes are dispersed in water together with an ionic surfactant or a polymer electrolyte such as a polymer acid or a polymer base, and are heated to a melting point or higher, and can be applied with a homogenizer or a pressure discharger capable of imparting a strong shearing force. It can be made into fine particles by using a type disperser, and a dispersion liquid of particles of 1 μm or less can be prepared. Further, these release agent fine particles may be added together with the other resin fine particle components to the mixed solvent at once, or may be divided and added in multiple stages.

As the colorant used in the toner of the present invention,
Carbon black, chrome yellow, hansa yellow,
Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrazolone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Brillantamine 3B, Brillantamine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Various pigments such as Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, and Acridine, Xanthene, Azo, Benzoquinone, Azine Type, anthraquinone type, thioindico type, dioxazine type, thiazine type, azomethine type, indico type, thioindico type, Taroshianin system, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, thiazole-based, can be used in conjunction with various dyes and the like alone, or two or more such xanthene.

As these dispersing methods, any method,
For example, a general shearing method such as a rotary shearing homogenizer, a ball mill, a sand mill, and a dyno mill having a medium can be used, and there is no limitation. Further, these colorant fine particles may be added together with the other fine particle components to the mixed solvent at once,
It may be divided and added in multiple stages.

When used as a magnetic toner, a magnetic powder is contained. Examples of the magnetic powder used here include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys and compounds containing these metals. And the like. 4 if necessary
Various commonly used charge control agents such as quaternary ammonium salts, nigrosine compounds and triphenylmethane pigments may be added.

Further, a conventional toner external additive can be contained in the toner. Specifically, inorganic fine particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate can be used by being dispersed with an ionic surfactant, a polymer acid, or a polymer base. The method of dispersing the magnetic powder, the charge controlling agent, and other external additives can be added in the same manner as the above-described coloring agent.

These resin fine particle dispersions, colorant dispersions, and the like are mixed to prepare a uniform mixed particle dispersion, and an inorganic metal salt soluble in a dispersion medium is added and mixed to obtain desired aggregated particles. . At this time, the resin fine particles, the coloring agent, if necessary, the inorganic fine particles and the like may be added at once, or the fine particle component may be divided and added stepwise, and the configuration of the aggregated particles may be, for example, a core-shell structure, A structure in which components are inclined in the radial direction of the particles may be provided. In this case, a dispersion of the resin fine particles, a dispersion of the colorant particles, and a dispersion of the release agent fine particles are mixed and dispersed, and the aggregated particles are grown until the particle diameter reaches a certain level. If necessary, additional resin fine particles may be adhered to the surface of the aggregated particles by further adding a resin fine particle dispersion or the like. By the additional resin fine particles covering the aggregated particle surface,
It is possible to prevent a colorant, a release agent and the like from being exposed on the toner surface, and it is effective to suppress poor charging and uneven charging due to the exposure.

In the above coagulation step, a divalent or higher valent inorganic metal salt is used as the coagulant, but it is preferably trivalent or higher, particularly preferably tetravalent. The larger the valence of the inorganic metal, the stronger the cohesive force and the more stable the coagulation can be controlled. Therefore, non-agglomerates are less likely to occur, and an excellent particle size distribution can be obtained. As the polyvalent inorganic metal salt polymer, polyaluminum chloride, polyaluminum hydroxide and the like can be used.

After obtaining the aggregated particles having a desired particle diameter in this manner, the aggregated particles can be fused by heating to a temperature higher than the glass transition point of the resin to obtain desired toner particles. Here, by selecting the fusion heating conditions,
The toner shape can be controlled from an irregular shape to a spherical shape. When fusing at a high temperature for a long time, the toner shape becomes closer to a true sphere.

When fusing at a high temperature or fusing at a high concentration, any stabilizing treatment, for example, agglomerated particles may be used to prevent fusion of the agglomerated particles and maintain a sharp particle size distribution. A method of adding a surfactant, a polymer protective colloid, or the like having the same charge as the resin fine particles to be used can be employed, but the stabilizing surfactant used here is adsorbed on the surface of the aggregated particles, and the residual interface Causes activator. Therefore, without adding these surfactants, stabilization by ionic dissociation groups contained in the resin binder,
That is, it is preferable to adjust the pH of the system.

Therefore, the most preferred embodiment of the present invention is that when water is used as the solvent in the aggregation step,
For example, when resin fine particles obtained by an emulsion polymerization method and a colorant are dispersed in water to form aggregated particles and fused,
By controlling H between 2.0 and 14 to control the electric attraction and repulsion of the fine particles, the progress of aggregation can be stopped and the dispersion system can be stabilized. In this case, generally, if the surface potential is of the cationic type, the lower pH
In the case of an anionic type, it can be stabilized at a higher pH.However, when the pH is out of the above range, the viewpoint of chemical decomposition stability such as hydrolysis of resin fine particles and the like, and the transient stability are further improved. This is a problem from the viewpoint of destruction of the aggregated particles themselves.

The fused particles obtained by the fusion are subjected to a solid-liquid separation step such as filtration, and if necessary, a washing step and a drying step to obtain toner particles. In this case, it is preferable to sufficiently wash the toner in order to secure charging characteristics and reliability. In particular, when resin particles and the like obtained by an emulsion polymerization method are used and the solvent is water, the washing water is preferably used. After washing with alkaline water having a pH of 7 or more, it is preferable to further wash with acidic washing water having a pH of 6 or less.

In the drying step, an ordinary vibration-type fluidized drying method,
Any method such as a spray drying method, a freeze drying method, and a flash jet method can be employed. The toner particles have a moisture content after drying of 1.0% or less, preferably 0.1% or less.
It is desirable to adjust it to 5% or less.

The absolute value of the charge amount of the toner is 10 to
A range of 40 μC / g, preferably a range of 15 to 35 μC / g, is suitable. When the charge amount falls below 10 μC / g,
Background stain (fog) is likely to occur, and 40 μC / g
If it exceeds, the image density tends to decrease. Further, in the summer of the electrostatic image developing toner (high temperature and high humidity: 28 ° C., 85% R)
H) and the amount of charge in winter (low temperature and low humidity: 10 ° C., 30)
% (High-temperature high-humidity charge amount) / (low-temperature low-humidity charge amount) environment-dependent index is in the range of 0.2 to 1.3, preferably in the range of 0.7 to 1.0. It is. If this ratio is out of the above range, it becomes a factor that impairs charging stability and reliability under high temperature and high humidity.

Further, the toner of the present invention can be used as a developer by blending various external additives in the same manner as in the conventional kneading and pulverizing type toner. Inorganic fine particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate and tricalcium phosphate as external additives, silica, alumina, titania, inorganic particles such as calcium carbonate and silica as fluidity aids and cleaning aids, vinyl Fine resin particles such as resin, polyester, and silicone can be added to the surface of the toner particles by applying a shearing force in a dry state.

[0045]

EXAMPLES The present invention will be described in detail with reference to specific examples, but the present invention is not limited by these examples. Preparation of resin fine particle dispersion liquid (1) Styrene 370 parts by weight n-butyl acrylate 30 parts by weight Sodium styrene sulfonate 3 parts by weight Dodecanethiol 5 parts by weight Carbon tetrabromide 4 parts by weight 25 g of a monomer solution obtained by mixing the above components and ions Exchange water 5
50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added to 50 g of the flask while dispersing and slowly stirring and mixing for 10 minutes. Thereafter, the inside of the flask is sufficiently replaced with nitrogen, and the system is heated to 70 ° C. in an oil bath while stirring, and emulsion polymerization is performed for 30 minutes. The polymerization was continued at 70 ° C.
After an hour, the polymerization was terminated.

The number average particle diameter D _50n of the obtained resin fine particles was measured using a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).
nm and a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC
The glass transition point of the resin was measured at a heating rate of 10 ° C./min using -50) and found to be 59 ° C., using a molecular weight measuring device (manufactured by Tosoh Corporation, HLC-8020) and using THF as a solvent and weight average molecular weight. When measured (in terms of polystyrene), it was 13,000.

Preparation of Resin Particle Dispersion (2) 280 parts by weight of styrene 120 parts by weight of n-butyl acrylate 3 parts by weight of sodium styrene sulfonate 25 g of a monomer solution containing the above components and 5 parts of ion-exchanged water
50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added to 50 g of the flask while dispersing and slowly stirring and mixing for 10 minutes. After that, the inside of the flask is sufficiently replaced with nitrogen, and the system is heated to 70 ° C. in an oil bath with stirring, and emulsion polymerization is performed for 30 minutes. The polymerization was continued at 70C after the completion of the dropwise addition.
After an hour, the polymerization was terminated. Resin fine particle dispersion obtained
When (2) was measured for various properties in the same manner as in the resin fine particle dispersion (1), the number average particle diameter D _{50n of the} resin fine particles was 29.
0 nm, glass transition point 53 ° C., weight average molecular weight 55
It was 10,000.

Preparation of Resin Fine Particle Dispersion (3) Styrene 370 parts by weight n-butyl acrylate 30 parts by weight Sodium styrene sulfonate 3 parts by weight Dodecanethiol 5 parts by weight Carbon tetrabromide 4 parts by weight 412 g of a solution obtained by mixing the above components, 6 g of a nonionic surfactant (Nonipol 400, manufactured by Sanyo Kasei Co., Ltd.) and 10 anionic surfactant (Neogen R, manufactured by Daiichi Pharmaceutical Co., Ltd.)
g was dissolved in 550 g of ion-exchanged water in a flask, dispersed and emulsified, and 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added while slowly stirring and mixing for 10 minutes. After that, the inside of the system was thoroughly purged with nitrogen, and then stirred to 70% in an oil bath.
C. and the emulsion polymerization was continued for 5 hours. The resulting resin fine particle dispersion (3) is a fat fine particle dispersion.
When various properties were measured in the same manner as in (1), the number average particle diameter D _{50n of} the resin fine particles was 162 nm, the glass transition point was 59 ° C., and the weight average molecular weight was _135,000 .

Preparation of Resin Fine Particle Dispersion (4) 280 parts by weight of styrene 120 parts by weight of n-butyl acrylate 3 parts by weight of sodium styrene sulfonate 403 g of a solution obtained by mixing the above components and a nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd.) 6 g of Nonipol 400) and an anionic surfactant (Neogen R, manufactured by Daiichi Pharmaceutical Co., Ltd.) 10
g was dissolved in 550 g of ion-exchanged water in a flask, dispersed and emulsified, and 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added while slowly stirring and mixing for 10 minutes. After that, the inside of the system was thoroughly purged with nitrogen, and then stirred to 70% in an oil bath.
C. and the emulsion polymerization was continued for 5 hours. The obtained resin fine particle dispersion (4) was measured for various properties in the same manner as for the resin fine particle dispersion (1). The resin fine particles had a number average particle diameter D _50n of 120 nm, a glass transition point of 60 ° C, and a weight. The average molecular weight was 620,000.

Preparation of Resin Fine Particle Dispersion (5) Polymerization was carried out according to the method of preparing resin fine particle dispersion (1) except that sodium styrene sulfonate was changed to acrylic acid in the preparation of resin fine particle dispersion (1). went.
The obtained resin fine particle dispersion (5) is a resin fine particle dispersion.
When various properties were measured in the same manner as in (1), the number average particle diameter D _{50n of} the resin fine particles was 310 nm, the glass transition point was 60 ° C., and the weight average molecular weight was 15,000.

Preparation of Resin Fine Particle Dispersion (6) Polymerization was carried out according to the method of preparing resin fine particle dispersion (1) except that sodium styrene sulfonate was changed to methacrylic acid in the preparation of resin fine particle dispersion (1). went. When the obtained resin fine particle dispersion (6) was measured for various properties in the same manner as the resin fine particle dispersion (1), the number average particle diameter D _{50n of the} resin fine particles was 315 nm, the glass transition point was 59 ° C, and the weight was _50%. The average molecular weight was 13,500.

Preparation of Colorant Dispersion (1) 50 parts by weight of carbon black (manufactured by Cabot, Mogal L) 5 parts by weight of anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku) 200 parts by weight of ion-exchanged water The above components were dispersed with a homogenizer (trade name: Ultra Turrax T50, manufactured by LKA) for 10 minutes.
A colorant dispersion liquid (1) having a black color of ₅₀ nm and a _thickness of 250 nm was obtained.

Preparation of Colorant Dispersion (2) 50 parts by weight of phthalocyanine pigment (PB FAST BLUE9, manufactured by BASF Corp.) 5 parts by weight of anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 200 parts by weight of ion-exchanged water Part The above components were dispersed with a homogenizer (manufactured by LKA, Ultra Turrax T50) for 10 minutes, and further dispersed with an ultrasonic irradiator (RUS-600, manufactured by Nippon Seiki Seisakusho), and the number average particle diameter D _50n was 150 nm blue. Colorant dispersion (2)
I got

Preparation of Colorant Dispersion (3) 50 parts by weight of yellow pigment (Yellow 80, manufactured by Hoechst) 5 parts by weight of anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 200 parts by weight of ion-exchanged water The components were dispersed with a homogenizer (Ultra Turrax T50, manufactured by LKA) for 10 minutes, and further dispersed with an ultrasonic irradiator (RUS-600, manufactured by Nippon Seiki Seisakusho), and yellow colored with a number average particle diameter D _50n of 150 nm. Agent dispersion
(3) was obtained.

Preparation of Colorant Dispersion (4) 50 parts by weight of red pigment (PR122, manufactured by Dainichi Seika) 5 parts by weight of anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku) 200 parts by weight of ion-exchanged water Part The above components are dispersed for 10 minutes with a homogenizer (Ultra Turrax T50, manufactured by LKA), and further dispersed with an ultrasonic irradiator (RUS-600, manufactured by Nippon Seiki Seisakusho), and a red having a number average particle diameter D _50n of 250 nm. Colorant dispersion
(4) was obtained.

Preparation of release agent fine particle dispersion liquid (1) 50 parts by weight of paraffin wax (HNP0190, manufactured by Nippon Seiro, melting point 85 ° C.) 5 parts by weight of cationic surfactant (Sanisol B50, manufactured by Kao Corporation) Ion exchange 200 parts by weight of water The above components were sufficiently dispersed while heating to 95 ° C. with a homogenizer (manufactured by LKA, Ultra Turrax T50), and then an ultrasonic irradiator (RUS-60, manufactured by Nippon Seiki Seisaku-sho, Ltd.)
The dispersion treatment was performed in 0) to obtain a release agent fine particle dispersion liquid (1) having a number average particle diameter D _50n of the release agent fine particles of 550 nm.

Comparative Example 1 Resin Fine Particle Dispersion (3) 120 parts by weight Resin Fine Particle Dispersion (4) 80 parts by weight Colorant Dispersion (1) 30 parts by weight Release Agent Dispersion (1) 40 parts by weight Cation 1.5 parts by weight of a surfactant (Sanisol B50, manufactured by Kao Corporation) The above components were placed in a round stainless steel flask, mixed and dispersed sufficiently with a homogenizer (manufactured by LKA, Ultra Turrax T50), and then heated. After heating the flask to 48 ° C. while stirring it in an oil bath for heating and holding at that temperature for 30 minutes, the temperature of the oil bath for heating was further raised to 50 ° C. and held at that temperature for 1 hour to obtain aggregated particles. .

The number average particle diameter D of the aggregated particles_50nThe
Measurement using a counter (TAII, manufactured by Nikkaki Co., Ltd.)
It was 5.5 μm when determined, and the number average particle size distribution index
GSDn was 1.27. Where the number average particle diameter
D_50nAnd the number average particle size distribution index GSDn are measured
The particle size distribution is divided into
Particles whose cumulative distribution is drawn from small particle diameters and whose number is 16%
The diameter is the number average particle diameter D _16n, The particle size at which the number accumulation becomes 50%
Is the number average particle size D_50n, The particle size with a cumulative number of 84%
Number average particle size D_84nAnd the ratio of the number average particle diameter (D_84n
/ D_16n)^1/2Is the number average particle size distribution coefficient GSDn.
Was.

After adding 3 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Pharmaceutical Co., Ltd.) to the aggregated particle dispersion to stop the aggregation of the particles and stabilize the aggregated particles, the stainless steel flask is sealed. Then, the mixture was heated to 97 ° C. while continuing stirring using a magnetic seal, and kept for 3 hours to fuse the aggregated particles. When the number average particle diameter D _50n of the fused particles was measured using a Coulter counter (TAII manufactured by _Nikkaki Co., Ltd.), it was 5.5 μm, and the number average particle size distribution index GSD was found.
n was 1.27.

After cooling the fused particles, the particles were filtered,
After sufficiently washing with 6.5 ion-exchanged water and drying with a freeze dryer, the water content of the obtained toner particles was measured by a water content meter (MA30, manufactured by Sartorius) and found to be 0.55%. When the number average particle diameter D _50n of the toner particles was measured using a Coulter counter (TAII, manufactured by _Nikkaki Co., Ltd.), it was 5.5 μm.
SDn was 1.27.

When the surface state of the toner particles was observed with an electron microscope, a continuous layer in which resin fine particles were fused to the particle surface was confirmed. When the cross section of the toner was observed with a transmission electron microscope, almost no exposure of the pigment to the surface layer was observed. Further, the circumference length (ML) and the projected area (A) of 100 toners were measured using a Luzex image analyzer (LUZEXIII, manufactured by Nicolet), and (ML ² /
A) × (1 / 4π) × 100 is calculated and the shape factor SF1
Was 125 when the average value was determined.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high-temperature and high-humidity environment was -1.0 μC / g, and the charge amount in a low-temperature and low-humidity environment was -12.0 μC / g. It shows low charging characteristics and its environment-dependent index (28 ° C., 85
Q / M at% RH) / (Q / M at 10 ° C, 30% RH)
M) was as low as 0.08, indicating a problem with the environment.

Further, the residual surfactant amount of the toner particles was determined by the following method, and the total amount was defined as the residual surfactant amount. In addition, the quantitative value by the tetrathiocyanocobaltic acid method shown below was defined as the residual nonionic surfactant amount. First, 1 g of toner particles is put into 6 g of acetone, a binder resin component of the toner particles is once dissolved, and a surfactant on the toner surface and inside is extracted into acetone. Was added to precipitate a binder resin again. Insoluble matters such as a binder resin component and pigment particles were removed by filtration, and acetone was removed from the acetone / ion-exchanged water filtrate by an evaporator. An ethanol solution was prepared.

Thereafter, the cation exchanger and the anion exchanger were sequentially trapped in the ethanol solution, and each ion exchanger was washed away with a 2N HCl solution, and then the anions were colored by the bromocresol green quinine method. The cations were colored by the ethyl violet method based on the absorbance at 610 nm and quantified by the absorbance at 611 nm. Further, the 95% ethanol solution which had passed through the above ion exchanger was colored by the tetrathiocyanocobaltic acid method, and the nonionic surfactant was quantified by the absorbance at 322 nm (quantification limit was 10 ppm). The total amount of the anion, cation and nonionic surfactant obtained by the above method was 1.5% by weight. The amount of the nonionic surfactant was 10,000 ppm.

Further, with respect to 100 g of the toner particles,
Hydrophobic silica (TS720, manufactured by Cabot Corporation)
3 g was added and mixed by a sample mill and added. Then, the externally added toner was weighed to a ferrite carrier having an average particle size of 50 μm coated with 1% of methacrylate (manufactured by Soken Chemical Co., Ltd.) so that the toner concentration was 5%.
The mixture was stirred and mixed with a ball mill for 5 minutes to prepare a developer.
This developer was subjected to a copying test of 10,000 sheets each in a high-temperature and high-humidity environment (28 ° C., 85% RH) and a low-temperature, low-humidity environment (10 ° C., 30% RH) using a Fuji Xerox V500 modified copier. An evaluation was performed. As a result, remarkable fogging occurs in both environments, scattering of toner is observed,
In addition, a remarkable decrease in image quality was observed.

[Example 1] Resin fine particle dispersion (1) 120 parts by weight Resin fine particle dispersion (2) 80 parts by weight Colorant dispersion (1) 30 parts by weight Release agent dispersion (1) 40 parts by weight Poly 0.4 parts by weight of aluminum chloride (PAC100W, manufactured by Asada Chemical Co., Ltd.) The above components were placed in a round stainless steel flask, thoroughly mixed and dispersed with a homogenizer (manufactured by LKA, Ultra Turrax T50), and then heated. The flask was heated to 48 ° C. with stirring in a bath, kept at that temperature for 30 minutes, and then the temperature of the heating oil bath was raised and kept at 50 ° C. for 1 hour to obtain aggregated particles.

When the number average particle diameter D _50n of the aggregated particles was measured using a Coulter counter (TAII, manufactured by _Nikkaki Co., Ltd.), it was 5.5 μm.
SDn was 1.25. After adding 3 parts by weight of an anionic surfactant (manufactured by Daiichi Pharmaceutical Co., Ltd., Neogen R) to the aggregated particle dispersion to stabilize the aggregated particles by stopping the aggregation of the particles, the stainless steel flask was sealed, The temperature was raised to 97 ° C. and maintained for 3 hours while stirring was continued using a magnetic seal, and the aggregated particles were fused by heating. The number average particle diameter D _50n of the fused particles was measured by the above-mentioned Coulter counter, and was 5.5 μm, and the number average particle size distribution index GSDn was 1.25.

After the fused particles were sufficiently washed with ion-exchanged water having a pH of 6.5, they were freeze-dried to obtain toner particles.
The measured water content was 0.50%. When observing the surface state of the toner particles with an electron microscope, resin fine particles,
It was confirmed that the resin fine particles were fused to the surface of the core particles composed of the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, the shape factor SF1 was measured in the same manner as in Comparative Example 1 using the above-mentioned Luzex image analysis apparatus.
Met.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high-temperature and high-humidity environment was −18.0 μC / g, and the charge amount in a low-temperature and low-humidity environment was −24.0 μC / g. It shows charging characteristics and its environment-dependent index is as high as 0.75, indicating that it has excellent environment-dependency.

When the amount of the surfactant remaining in the toner particles was determined in the same manner as in Comparative Example 1, the total amount of the surfactant was 0.5% by weight. The amount of the agent was below the measurement limit of 10 ppm. The toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1 and mixed with a sample mill and added. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% R
H) and a low-temperature, low-humidity environment (10 ° C., 30% RH), 100
A copy test of 00 sheets was performed to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

Example 2 Resin Fine Particle Dispersion (1) 120 parts by weight Resin Fine Particle Dispersion (2) 80 parts by weight Colorant Dispersion (2) 30 parts by weight Release Agent Dispersion (1) 40 parts by weight Poly 0.4 parts by weight of aluminum chloride (PAC100W, manufactured by Asada Chemical Co., Ltd.) The above components were placed in a round stainless steel flask, thoroughly mixed and dispersed with a homogenizer (manufactured by LKA, Ultra Turrax T50), and then heated. The flask was heated to 50 ° C. while stirring in a bath, and coagulated at that temperature for 1 hour. The pH of the aggregated particle dispersion at 50 ° C. was measured to be 3.5. 1N Na
After adjusting the pH at 50 ° C. to 10 by adding an OH aqueous solution, 3 parts by weight of an anionic surfactant (Neogen R, manufactured by Daiichi Pharmaceutical Co., Ltd.) was added to 270 parts by weight of the aggregated particle dispersion, After stopping the aggregation and stabilizing the aggregated particles, the stainless steel flask was sealed and heated to 97 ° C. while stirring with a magnetic seal, and held for 6 hours to fuse the aggregated particles. When the number average particle diameter D _50n of the fused particles was measured, it was 5.3 μm, and the number average particle size distribution coefficient index GSDn was 1.22.

The fused particles were sufficiently washed with an alkaline aqueous solution of NaOH at a pH of 10, further washed with an acidified aqueous solution of nitric acid at a pH of 3 and finally washed with ionic water at a pH of 6.5.
Lyophilization was performed to obtain toner particles. The measured water content was 0.49%. Observation of the surface state of the toner particles with an electron microscope confirmed that the resin fine particles were fused to the surface of the core particle composed of the resin fine particles, the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, when the shape factor SF1 was measured in the same manner as in Comparative Example 1 using the above-mentioned Luzex image analyzer, it was 120. Further, the total amount of residual surfactant obtained in the same manner as in Example 1 was 0.1
% By weight, and the amount of the nonionic surfactant was 10 ppm or less.

Using the above-mentioned toner particles, each was left for 12 hours in a high-temperature and high-humidity environment (28 ° C., 85% RH) and a low-temperature and low-humidity environment (10 ° C., 30% RH) without adding external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high-temperature and high-humidity environment was −25.0 μC / g, and the charge amount in a low-temperature and low-humidity environment was −27.0 μC / g. Shows good charging characteristics and has an environment-dependent index of 0.93.
And a high value, which proved to be excellent in environmental dependency.

Further, the toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1, and mixed and added by a sample mill. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 3
(0% RH), a copy test of 10,000 sheets was performed on each of the modified copy machines manufactured by Fuji Xerox Co., Ltd. to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

Example 3 Resin Fine Particle Dispersion (1) 120 parts by weight Resin Fine Particle Dispersion (2) 80 parts by weight Colorant Dispersion (3) 30 parts by weight Release Agent Dispersion (1) 40 parts by weight Poly 0.4 parts by weight of aluminum chloride (PAC100W, manufactured by Asada Chemical Co., Ltd.) The above components are placed in a round stainless steel flask and homogenized (L50, manufactured by LKA, T50 manufactured by Ultra Turrax).
And sufficiently coagulated at 50 ° C. for 1 hour.
At that time, the pH of the aggregated particle dispersion at 50 ° C. was measured, and it was 3.5. 1N is added to this aggregated particle dispersion.
NaOH aqueous solution was added to adjust the pH at 50 ° C to 10
Then, the mixture was heated to 97 ° C. as in Example 1, and the heating time was changed from 6 hours to 8 hours to obtain fused particles.
The number average particle diameter D _50n of the fused particles was 5.2 μm as measured by the above Coulter counter, and the number average particle size distribution index GSDn was 1.24.

After washing the fused particles sufficiently with NaOH alkaline water at pH 10, further washing with acidic nitric acid at pH 3, and finally with ionic water at pH 6.5,
Lyophilization was performed to obtain toner particles. The measured water content was 0.50%. Observation of the surface state of the toner particles with an electron microscope confirmed that the resin fine particles were fused to the surface of the core particle composed of the resin fine particles, the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, the shape factor SF1 was measured using the above-mentioned Luzex image analyzer in the same manner as in Comparative Example 1, and it was 115. Further, the total amount of the residual surfactant obtained in the same manner as in Example 1 was 0.1.
It was 2% by weight, and the amount of the nonionic surfactant was 10 ppm or less, which was the measurement limit.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high-temperature and high-humidity environment was −24.0 μC / g, and the charge amount in a low-temperature and low-humidity environment was −26.0 μC / g. Exhibits good charging characteristics and has an environment-dependent index of 0.92
And a high value, which proved to be excellent in environmental dependency.

Further, the toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1, and mixed and added by a sample mill. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 3
(0% RH), a copy test of 10,000 sheets was performed on each of the modified copy machines manufactured by Fuji Xerox Co., Ltd. to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

Example 4 Resin Fine Particle Dispersion (1) 120 parts by weight Resin Fine Particle Dispersion (2) 80 parts by weight Colorant Dispersion (4) 30 parts by weight Release Agent Dispersion (1) 40 parts by weight Poly 0.4 parts by weight of aluminum chloride (PAC100W, manufactured by Asada Chemical Co., Ltd.) The above components are placed in a round stainless steel flask and homogenized (L50, manufactured by LKA, T50 manufactured by Ultra Turrax).
And sufficiently coagulated at 50 ° C. for 1 hour.
At that time, the pH of the aggregated particle dispersion at 50 ° C. was measured, and it was 3.5. 1N is added to this aggregated particle dispersion.
NaOH aqueous solution was added to adjust the pH at 50 ° C to 10
Then, the mixture was heated to 95 ° C., and the heating time was set to 6 hours to obtain fused particles. Number average particle diameter D _{50n of} fused particles
Was 5.5 as measured by the above Coulter counter.
μm, and the number average particle size distribution index GSDn is 1.23.
Met.

The fused particles were sufficiently washed with an alkaline aqueous solution of NaOH at a pH of 10, further washed with an acidified aqueous solution of nitric acid at a pH of 3 and finally washed with ionic water at a pH of 6.5.
Lyophilization was performed to obtain toner particles. The measured water content was 0.49%. Observation of the surface state of the toner particles with an electron microscope confirmed that the resin fine particles were fused to the surface of the core particle composed of the resin fine particles, the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, the shape factor SF1 was measured using the above-described Luzex image analyzer in the same manner as in Comparative Example 1, and was 135. Furthermore, the total amount of the residual surfactant determined in the same manner as in Example 1 was 0.1% by weight, and the amount of the nonionic surfactant was 10 ppm or less, which is the measurement limit.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high-temperature and high-humidity environment was −27.0 μC / g, and the charge amount in a low-temperature and low-humidity environment was −30.0 μC / g. It shows good charging characteristics and has an environment-dependent index of 0.90.
And a high value, which proved to be excellent in environmental dependency.

Further, the toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1, and mixed and added by a sample mill. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 3
(0% RH), a copy test of 10,000 sheets was performed on each of the modified copy machines manufactured by Fuji Xerox Co., Ltd. to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

Example 5 Coagulated particles were obtained in the same manner as in Example 1 except that the resin fine particle dispersion (1) used in Example 1 was changed to the resin fine particle dispersion (5).
The number average particle diameter D _50n of the fused particles was 5.1 μm as measured by the Coulter counter, and the number average particle size distribution index GSDn was 1.23.

The fused particles were sufficiently washed with an alkaline aqueous solution of NaOH at a pH of 10, further washed with an acidified aqueous solution of nitric acid at a pH of 3 and finally washed with ionic water at a pH of 6.5.
Lyophilization was performed to obtain toner particles. The measured water content was 0.48%. Observation of the surface state of the toner particles with an electron microscope confirmed that the resin fine particles were fused to the surface of the core particle composed of the resin fine particles, the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, when the shape factor SF1 was measured in the same manner as in Comparative Example 1 using the above-mentioned Luzex image analyzer, it was 120. Further, the total amount of the residual surfactant obtained in the same manner as in Example 1 was 0.5
% By weight, and the amount of the nonionic surfactant was 10 ppm or less.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high temperature and high humidity environment was −25.0 μC / g, and the charge amount in a low temperature and low humidity environment was −28.0 μC / g. Exhibits good charging characteristics and has an environment-dependent index of 0.89
And a high value, which proved to be excellent in environmental dependency.

Further, the toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1, and mixed and added by a sample mill. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 3
(0% RH), a copy test of 10,000 sheets was performed on each of the modified copy machines manufactured by Fuji Xerox Co., Ltd. to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

Example 6 Coagulated particles were obtained in the same manner as in Example 1 except that the resin fine particle dispersion (1) used in Example 1 was changed to the resin fine particle dispersion (6).
The number average particle size D _50n of the fused particles was measured by the above-mentioned Coulter counter, and was 5.2 μm, and the number average particle size distribution index GSDn was 1.23.

After washing the fused particles sufficiently with NaOH alkaline water at pH 10, further washing with acidic nitric acid at pH 3, and finally with ionic water at pH 6.5,
Lyophilization was performed to obtain toner particles. The measured water content was 0.47%. Observation of the surface state of the toner particles with an electron microscope confirmed that the resin fine particles were fused to the surface of the core particle composed of the resin fine particles, the colorant and the release agent to form a continuous layer. When the cross section of the toner was observed with a transmission electron microscope, the exposure of the pigment to the toner surface layer was hardly observed. Further, when the shape factor SF1 was measured in the same manner as in Comparative Example 1 using the above-mentioned Luzex image analyzer, it was 120. Further, the total amount of the residual surfactant obtained in the same manner as in Example 1 was 0.5
% By weight, and the amount of the nonionic surfactant was 10 ppm or less.

Using the above toner particles, each was left for 12 hours in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 30% RH) without adding any external additives. Thereafter, when the charge amount (μC / g) was measured, the charge amount (Q / M) in a high temperature and high humidity environment was −25.0 μC / g, and the charge amount in a low temperature and low humidity environment was −29.0 μC / g. Exhibits good charging characteristics and has an environment-dependent index of 0.86
And a high value, which proved to be excellent in environmental dependency.

Further, the toner particles were mixed with hydrophobic silica in the same manner as in Comparative Example 1, and mixed and added by a sample mill. Then, the developer was similarly adjusted using the same coat carrier as in Comparative Example 1. This developer is used in a high temperature and high humidity environment (28 ° C., 85% RH) and a low temperature and low humidity environment (10 ° C., 3
(0% RH), a copy test of 10,000 copies was performed with a V500 modified copier manufactured by Fuji Xerox Co., Ltd. to evaluate the image quality. As a result, fogging and toner scattering were hardly observed in both environments, and almost excellent image characteristics were recognized.

[0091]

[Table 1]

As is clear from comparison between the comparative example and the example in Table 1, in the example, the total amount of the surfactant remaining in the toner in the emulsion polymerization aggregation method was suppressed to 1.0% by weight or less. And especially the amount of nonionic surfactant is 100 pp
m or less, and a sharp particle size distribution with a number average particle size distribution index GSDn of 1.26 or less can be ensured. As a result, excellent chargeability, environmental dependency, excellent particle size distribution and excellent charge characteristics It has been confirmed that a toner for developing an electrostatic image having excellent image quality characteristics can be provided.

[0093]

According to the present invention, the above configuration is adopted.
Resin fine particle dispersion prepared without using surfactant
Agglomeration particles are prepared using a multivalent inorganic metal salt and then fused to form toner particles, which can be achieved by conventional aggregation-fusion methods using surfactants, suspension polymerization methods, and kneading and pulverization methods. It has become possible to obtain a toner for developing an electrostatic image, which cannot be obtained and has a small particle size, a sharp particle size distribution, excellent charging characteristics and environmental resistance characteristics in a well-balanced manner. Furthermore, an image having excellent image quality characteristics can be formed by an electrostatic image developer using these toners.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Ishiyama 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Yasuo Kadokura 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72) Inventor Tsuyoshi Shoko 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture F-Xerox Co., Ltd. F-term (reference) 2H005 AA01 AA06 AA21 AB03 CA04 CA14 CA21 CA23 CB08 CB18 EA03 EA05 EA07 FA01

Claims (4)

[Claims] 1. An electrostatic image developing toner containing a binder resin and a colorant, wherein the toner has a number average particle diameter D.
_50n is 1 to 10 _μm , and the number average particle size distribution index GSDn
Is not more than 1.26, the total surfactant content in the toner particles is not more than 1.0% by weight, the nonionic surfactant content is not more than 100 ppm, and the binder resin is hydrophilic. A toner for developing an electrostatic image, comprising a self-dispersing resin containing a neutral ethylenically unsaturated monomer. 2. A dispersion of fine particles of a self-dispersible resin containing a hydrophilic ethylenically unsaturated monomer and a dispersion of a colorant, and the resin is mixed with an inorganic metal salt having a charge of at least two valences. After preparing the aggregated particle dispersion by aggregating the fine particles and the colorant, heating the resin to a temperature equal to or higher than the glass transition point of the resin to fuse the aggregated particles to form toner particles. 2. The method for producing a toner for developing an electrostatic image according to item 1. 3. An electrostatic image developer containing a toner and a carrier, wherein the electrostatic image developing toner according to any one of claims 1 to 7 is used. . 4. A step of forming an electrostatic latent image on an electrostatic charge carrier, a step of developing the electrostatic latent image with a developer on a developer carrier to form a toner image, and 4. An image forming method including a step of transferring onto a transfer body, wherein the electrostatic charge image developer according to claim 3 is used as the developer.