JPH11344827A - Electrostatic charge image developing toner and image forming method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner whose charge amt. does not become unstable, even when the toner is used for a long period of time, and to provide an image forming method using this toner. SOLUTION: In the electrostatic charge image developing toner comprising associated plural polymer fine particles, the total volume of pores having 0.1 μm or smaller pore diameter on the toner particle surface is 30% or less of the total pore volume of the toner particle surface. The polymer fine particles contain a monomer unit having ionic dissociative groups, and a part or the whole of the ionic dissociative groups are in a dissociated state.

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 in a copying machine, a printer and the like, and an image forming method using the same.

[0002]

2. Description of the Related Art Conventionally, generally used toners are prepared by appropriately dry-mixing a polymer obtained by various polymerization methods with a coloring agent such as carbon black, a charge controlling agent and / or a magnetic material, and then extruding the mixture. It is manufactured by melt-kneading, etc., followed by pulverization and classification.

However, the toner obtained by the above-described melt-kneading and pulverizing method has a limitation in controlling the toner particle size, and it is difficult to produce a small particle size toner with high yield. The components constituting the toner are not uniformly dispersed, and the charge distribution is likely to be broad. As a result, when it is used as a developer, it has the disadvantage that the resolution is low and fog, scattering, and the like are easily generated.

[0004] A method of directly manufacturing by suspension polymerization has also been proposed, but not only is it difficult to reduce the particle size, but also has the disadvantage that the particle size distribution becomes very wide. Further, the toner produced by the polymerization method basically has a true spherical shape. This spherical toner has the disadvantage that it is difficult to clean the residual toner on the electrophotographic photosensitive member.

That is, the methods disclosed in JP-A-60-220358 and JP-A-4-284461 are:
Although it is a method capable of obtaining non-spherical particles, it is difficult to control the particle size and particle size distribution, and it is necessary to classify to obtain desired particle size and particle size distribution after completion of the reaction. Furthermore, it is difficult to adjust the zeta potential of the pigment and the polymer particles by the method disclosed in JP-A-4-284461. Originally, even if produced by this method, unless the ratio between the large particles and the small particles is strictly specified, the specified characteristics cannot be obtained, but this specification is not provided, and the generated particles can have a strong structure. And has the disadvantage that it cannot have mechanical strength.

In order to improve these disadvantages, Japanese Patent Laid-Open Publication No.
No. 329947 has proposed a manufacturing method.

[0007]

However, it has been clarified that the charge amount of many of the toners produced by this method becomes unstable over a long period of use, and the same tendency is produced by other methods. It was also found that the polymer fine particle association type toner was present.

An object of the present invention is to provide a toner whose charge amount does not become unstable even after long-term use, and an image forming method using the same.

[0009]

The object of the present invention is achieved by adopting the following constitution.

[1] In a toner for developing an electrostatic image formed by assembling a plurality of polymer fine particles, the total volume of pores having a pore diameter of 0.1 μm or less on the surface of the toner particles is equal to the total pores on the surface of the toner particles. A toner for developing an electrostatic image, wherein the toner is 30% or less by volume.

[2] The toner for developing an electrostatic image according to [1], wherein the polymer fine particles contain a monomer unit having an ionic dissociation group.

[3] The polymer fine particle contains a monomer unit having an ionic dissociative group, and a part or all of the ionic dissociative group is in a dissociated state, [1] or [2]. For developing electrostatic images.

[4] An image forming method in which an electrostatic charge image formed on a photoreceptor is developed with a toner to form a toner image, wherein the toner is the toner described in [1]. .

[5] An image forming method for transferring a toner image formed on a photosensitive member onto a transfer material, wherein the toner is the toner described in [1]. [6] In an image forming method for transferring a toner image formed on a photoreceptor onto a transfer material and then cleaning and removing the toner remaining on the photoreceptor, it is preferable that the toner is the toner described in [1]. Characteristic image forming method.

As a result of extensive studies by the present inventors, the object of the present invention has been achieved by controlling the abundance of pores having a pore diameter of 0.1 μm or less on the surface of the toner particles relative to all the pores on the surface of the toner particles. It has been found that the stability of the charge amount of the toner can be improved. That is, since the toner prepared by the association method has a structure in which polymer fine particles are associated, it is necessary to make the adhesion between the particles dense. As a result of examining the adhesiveness, they have found that the adhesiveness can be improved by reducing the amount of pores having a specific pore size or less, and have completed the present invention. Although the reason is not clear, a specific pore size, that is, a large number of pores of 0.1 μm or less indicates that minute cracks are present from the particle surface to the inside. It is presumed that crushing occurs when a stress is applied to the, and the crushed pieces adhere to the carrier, which is a charging member, thereby causing a problem of lowering the chargeability. Therefore, it is presumed that by reducing the amount of the pores having a diameter of 0.1 μm or less, the crushing of the toner particles themselves becomes difficult to proceed.

The pore volume on the surface of the toner can be controlled by the solvent used to wash impurities after the toner is formed in an aqueous system. In this case, it is preferable to wash with a solvent that does not dissolve the resin constituting the toner. Examples of the solvent that does not dissolve such a resin include water, methanol, ethanol, and isopropyl alcohol. Further, it is particularly preferable to wash with a solvent that does not swell the resin. When a solvent that swells without dissolving the resin constituting such a toner is used, the solvent may enter the inside of the particles, and fine cracks may be generated when the solvent is dried.

As another method for controlling the pore volume of the toner surface, the temperature and speed at which the washed toner is dried can be increased. That is, by increasing the drying temperature, the vicinity of the surface of the resin constituting the toner particles is raised to near the glass transition temperature, whereby the adhesion between the particles can be improved. As a drying rate, a method of drying slowly rather than a rapid drying is preferable.
Although the reason for this is not clear, the rapid drying accelerates the drying of the particle interface and causes a problem of fine cracks on the surface.

From the above viewpoint, the drying temperature is preferably a glass transition temperature of the resin forming the polymer of -0 to 25 ° C.
Drying under atmospheric pressure is preferable to vacuum drying in order to make the drying conditions not rapid drying.

Here, the pore volume of the toner surface is measured by a mercury intrusion type pore distribution measuring device. As measurement conditions, high pressure measurement was used, and 0.50 psia
Measurements are made in the pressure range from to 30000.00 psia. From the histogram showing the relationship between the pore diameter and the volume according to the pore diameter, the sum of the volumes of the pore diameters of 0.1 μm or less is determined. This is defined as the total volume (A) of pores having a pore diameter of 0.1 μm or less. On the other hand, the total pore volume (B) of the whole toner is obtained, and the ratio can be obtained from the formula [(A) / (B)] × 100.

As for the pore volume on the toner surface, the total volume of pores having a pore size of 0.1 μm or less on the surface of the toner particles must be 30% or less of the total pore volume on the surface of the toner particles. More preferably, it is 25% or less. The total volume of pores having a pore diameter of 0.1 μm or less on the surface of the toner particles is 3
If it exceeds 0%, the charge amount decreases with the shaking time with the carrier, probably because the mechanical strength of the toner decreases.

The present invention has been accomplished based on such findings, and an object of the present invention is to provide non-spherical particles formed by assembling a plurality of polymer fine particles, and a method for producing the non-spherical particles. Is achieved, for example, by non-spherical particles characterized in that the particles are treated with an aggregating agent having a critical aggregating concentration of the polymer fine particle dispersion or higher and an organic solvent which is infinitely soluble in water.

A method for producing non-spherical particles comprising a plurality of polymer fine particles associated with each other, comprising: a) adding a coagulant having a critical coagulation concentration or more to a polymer fine particle dispersion; A step of adding an organic solvent that is infinitely soluble in water to the polymer fine particle dispersion to which the agent has been added, and c) a step of heating the mixture above the glass transition temperature of the polymer fine particles. This is achieved by a method for producing spherical particles.

Hereinafter, the present invention will be described in detail.

[Flocculant] The flocculant used in the present invention is preferably selected from metal salts.

Examples of the metal salt include salts of monovalent metals such as alkali metals such as sodium, potassium and lithium, salts of divalent metals such as alkaline earth metals such as calcium and magnesium and salts of manganese and copper. Valent metal salts, iron,
Examples thereof include trivalent metal salts such as aluminum.

Specific examples of these metal salts are shown below. Specific examples of monovalent metal salts include sodium chloride, potassium chloride, lithium chloride, and divalent metal salts such as calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Examples of the trivalent metal salt include aluminum chloride and iron chloride. These are appropriately selected according to the purpose. In general, the divalent metal salt has a lower critical aggregation concentration (coagulation value or coagulation point) than the monovalent metal salt, and the critical aggregation concentration of the trivalent metal salt is lower.

The critical aggregation concentration according to the present invention is an index relating to the stability of a dispersion in an aqueous dispersion, and indicates the concentration at which aggregation occurs when an aggregating agent is added. This critical aggregation concentration varies greatly depending on the latex itself and the dispersant. For example, Seizo Okamura et al., Polymer Chemistry 17,601
(1960), and the value can be known according to these descriptions. Further, as another method, a desired salt is added to the target particle dispersion at a different concentration,
The も potential of the dispersion can be measured, and the salt concentration at which the ζ potential starts to change can be used as the critical aggregation concentration.

The polymer fine particle dispersion is treated with a coagulant so as to have a concentration higher than the critical coagulation concentration. At this time, of course, whether to add the metal salt directly or as an aqueous solution is arbitrarily selected depending on the purpose. In the case of adding as an aqueous solution, the added metal salt needs to be at least the critical aggregation concentration of the polymer fine particle dispersion with respect to the volume of the polymer fine particle dispersion and the total volume of the metal salt aqueous solution.

The concentration of the metal salt as the coagulant in the present invention may be at least the critical coagulation concentration, but is preferably added at least 1.2 times, more preferably at least 1.5 times the critical coagulation concentration.

[Organic solvent that is infinitely soluble in water] A solvent that is infinitely soluble in water is a solvent that can uniformly form a mixed solution with water at any ratio. Is preferred not to dissolve. Specific examples include methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol,
Examples thereof include alcohols such as ethoxyethanol and butoxyethanol, nitriles such as acetonitrile, and dioxane.

The organic solvent infinitely soluble in water is appropriately selected from a range of 1 to 300% based on the flocculant-containing polymer fine particle dispersion.

[Polymer Fine Particles] As the polymer fine particles, generally, emulsion polymerization, suspension polymerization, dispersion polymerization, precipitation polymerization, interfacial polymerization, pulverized fine powder of synthetic resin, etc. can be used. Preferably, fine polymer particles produced by an emulsion polymerization method are used.

The particle size of these polymer fine particles can be arbitrarily used as long as it is equal to or less than the particle size of the target non-spherical particles. It is preferably in the range of 01 to 10 μm, particularly preferably 0.05 to 2.0 μm.

[Monomer] In order to obtain the polymer fine particles of the present invention, a hydrophobic monomer is used. Further, it is preferable to include a monomer having an ionic dissociative group. The monomer having the ionic dissociating group is 0.1% of the total monomer.
To 30% by weight, preferably 0.5 to 20% by weight. It is preferable that at least a part of the ionic dissociating group is in a dissociated state even after toner particles are formed.

Examples of the hydrophobic monomer of the present invention include styrene derivatives such as styrene, p-methylstyrene, o
-Methylstyrene, p-chlorostyrene, o-chlorostyrene, p-methoxystyrene, o-methoxystyrene, p-ethoxystyrene, p-butoxystyrene,
Examples include 2,4-dimethylstyrene, 2,4-dichlorostyrene, p-chloromethylstyrene, o-chloromethylstyrene, p-hydroxystyrene, o-hydroxystyrene and the like. Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylates such as cyclohexyl acrylate and dodecyl (meth) acrylate are also included.
Also, acrylonitrile, nitrile monomers such as methacrylonitrile, vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether, vinyl ester monomers such as vinyl acetate and vinyl butyrate, ethylene, propylene, isobutylene and the like. Olefinic monomers, conjugated dienes such as butadiene, isoprene, chloroprene, and dimethylbutadiene are also included. These may be used alone or in combination of two or more as necessary. Further, it is used in combination with the following monomer having an ion dissociable group.

The monomer unit having an ionic dissociating group is
Groups such as carboxyl group, sulfonic acid group, phosphoric acid group, amino group (including primary amine, secondary amine, tertiary amine, etc.) and quaternary ammonium salt are included in the monomer structure. Indicates a monomer. Specific examples include, for example, acrylic acid, methacrylic acid,
Maleic acid, itaconic acid, cinnamic acid, fumaric acid, monoalkyl maleate, monoalkyl itaconate, and the like. As monomers having a sulfonic acid group, styrene sulfonic acid, allyl sulfosuccinic acid, 2
-Acrylamide-2-methylpropanesulfonic acid, 2
-Sulfoethyl methacrylate and salts thereof. Examples of the monomer having a phosphate group include acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, and 3-chloro-2-acid phosphooxypropyl methacrylate.

Furthermore, an amino group-substituted acrylic (methacrylic) acid ester or acrylic (methacrylic) amide or an acrylic (methacrylic) amide mono- or disubstituted with an alkyl group having 1 to 18 carbon atoms on any N,
Or a vinyl compound substituted with a heterocyclic ring having N as a ring member and N, N-diallylalkylamine or a quaternary ammonium salt thereof. Specific examples of these acrylic (meth) acrylic acid esters include dialkylaminoalkyl (meth) acrylates (for example, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc.) and their acid salts or quaternary salts. Secondary ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt and the like.

Specific examples of acryl (methacrylic) amide or acryl (methacrylic) amide mono- or di-substituted with an alkyl group having 1 to 18 carbon atoms on any N include (meth) acrylamide, N- Butyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, piperazyl (meth) acrylamide, N
-Octadecyl methacrylamide and the like.

Specific examples of the vinyl compound substituted with a heterocyclic ring having N as a ring member and N, N-diallylalkylamine or a quaternary ammonium salt thereof include, for example, vinylpyridine, vinylpyrrolidone, vinylimidazole and the like. Examples thereof include quaternary ammonium salts, and N, N-diallylmethylammonium chloride and N, N-diallylethylammonium chloride.

Further, monomers having an active halogen such as vinylbenzyl chloride and vinylphenethyl chloride can also be used. For example, as a copolymer component, an appropriate amine is used after copolymerization is performed.
It is also possible to make a quaternary amine or a quaternary ammonium salt. Further, it can be copolymerized as a dialkylamine or a quaternary ammonium salt. For example, a dialkylamine can be introduced into vinylbenzyl chloride by reacting it with a monomer or by polymer reaction.

These various monomers are selected according to the purpose, for example, according to the desired glass transition temperature, melting temperature and the like.

[Radical Polymerization Initiator] In synthesizing the polymer fine particles of the present invention, a radical polymerization initiator is selected according to the polymerization method. That is, in the case of the suspension polymerization method, an oil-soluble radical polymerization initiator is used, and in the case of the emulsion polymerization method, a water-soluble radical polymerization initiator is used. Further, in the case of dispersion polymerization, it is appropriately selected depending on the dispersion medium used, but when using a non-aqueous solvent and when using a mixed solvent of a water-miscible organic solvent and water, a water-soluble radical polymerization initiator may be used. It is possible.

Examples of water-soluble radical polymerization initiators include persulfates such as potassium persulfate and ammonium persulfate.
Water-soluble peroxides such as hydrogen peroxide and the like, such as water-soluble azo compounds, for example, azobisaminodipropane acetate, azobiscyanovaleric acid and salts thereof, and the like can be mentioned.

Examples of the oil-soluble radical polymerization initiator include:
Oil-soluble peroxides such as benzoyl peroxide, lauroyl peroxide and the like can be mentioned. Examples of the oil-soluble azo polymerization initiator include azobisisobutyronitrile, azobisvaleronitrile and the like. The addition amount of these can be determined according to the molecular weight of the target polymer fine particles and the like. Further, if necessary, a molecular weight regulator, for example, a chain transfer agent represented by a thiol compound, for example, dodecanethiol, octylthiol and the like can be used.

The polymer fine particles according to the present invention may have a Tg in the range of -10 to 120 ° C, more preferably 0 to 90 ° C. The softening point is in the range of 80 to 220 ° C. The monomer composition of the polymer fine particles satisfies this range, and the polymer unit having a dissociable group may be contained in an amount of about 0.1 to 20% by weight based on the weight of the polymer. The type and composition of the copolymerized monomer are not limited.

The molecular weight of the polymer fine particles according to the present invention is not particularly limited, but when used as a toner, the weight average molecular weight is 2,000 to 1,000,000, preferably 8,000.
５００500,000. The molecular weight distribution is expressed as a ratio of weight average molecular weight to number average molecular weight (abbreviated as Mw / Mn).
It is 5 to 100, preferably 1.8 to 50.

[Solid Component] The polymer fine particles according to the present invention can be compounded with a solid component necessary for constituting a toner to form a toner. Commonly used solid components include pigments and dyes as colorants, and further, a fixing improver, a charge control agent, and the like can be used. These solid components can be associated with the polymer particles in a state of being dispersed in the aqueous medium, and further polymerized after being dispersed or dissolved in the monomer constituting the polymer particles when forming the polymer particles. A method of incorporating the polymer particles into the polymer fine particles per se can also be mentioned. These can all be used in combination.

The pigment includes an inorganic pigment and an organic pigment. As inorganic pigments, carbon black, grafted carbon, furnace black, carbon pigments such as thermatomic kabourne, magnetite, ferrite,
Bengala, titanium oxide, zinc white, silica, chromium oxide,
Metal oxide pigments such as cobalt blue, ultramarine, cerulean blue, mineral violet, and trilead tetroxide; metal powder pigments such as zinc powder, iron powder, and copper powder; zinc sulfide, cadmium red, mercury sulfide, and selenium red , Sulfide pigments such as cadmium yellow, molybdenum red,
Examples thereof include chromate pigments such as barium yellow, strontium yellow, and chromium yellow, and ferrocyanide pigments.

Examples of the organic pigment include compounds described in Color Index and the like. For example,
As cyan or green pigments, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I.
I. Pigment Blue 15: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

As a magenta or red pigment, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I.
I. Pigment Red 5, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1,
C. I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122,
C. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment red 144, C.I.
I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 178, C.I. I.
Pigment Red 222 and the like.

As the yellow or orange pigment, C.I.
I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I.
Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 13
8, C.I. I. Pigment Yellow 180 and the like.

Generally, organic cyan pigments include C.I.
I. Pigment Blue 15: 3 is known as copper-phthalocyanine, and magenta organic pigments such as C.I. I. Dimethylquinacridone known as CI Pigment Red 122 is C.I. I. Disazo yellow known as CI Pigment Yellow 17 is used.

Further, for example, low-molecular-weight polyethylene, low-molecular-weight polypropylene, oxidized polyethylene, oxidized polypropylene, acid-modified polyethylene, acid-modified polypropylene, polyolefin wax (for example, Toho Chemical Industry Co., Ltd.) Fixing agent such as Hitec Co., Ltd.).

Nigrosine electron donating dyes, metal salts of naphthenic acid and higher fatty acids, alkoxylated amines,
Positive charge control agents such as quaternary ammonium salts, alkylamides, metal complexes, pigments, fluorinated activators, and negative charges such as electron-accepting organic complexes, chlorinated paraffins, chlorinated polyesters, and sulfonylamines of copper phthalocyanine. Can be used.

Usually, these are each used in an amount of 0.1 to 2 relative to the polymer.
5% by weight is contained.

[Non-Sphericalization Reaction] The non-spherical particles according to the present invention (colored particles, which may be used as they are as described below as toner, or may be further added with an external additive to form toner) are used in the present invention. It is produced by associating a plurality of the polymer fine particles of the present invention. As described above, at this time, the colorant
At the time of associating a plurality of polymer fine particles, they may be added simultaneously as a dispersion, and may be combined at the time of association.

The non-spherical particles of the present invention are prepared by adding a metal salt as a coagulant to a dispersion of the polymer fine particles of the present invention with stirring at a concentration higher than the critical coagulation concentration, and more preferably an organic solvent which is infinitely soluble in water. It can be achieved by adding and heating at a temperature not lower than the Tg of the polymer fine particles.

According to the present invention, the average particle size and particle size distribution of the non-spherical particles are (1) a coagulant concentration, (2) an addition concentration of an organic solvent infinitely soluble in water, and (3) an ion concentration of polymer particles. It is determined by the degree of dissociation of a monomer unit having a sex-dissociable group.
For example, when the addition concentration of an organic solvent infinitely soluble in water, the temperature and the degree of dissociation of the monomer unit having an ionic dissociation group of the polymer particles are constant, if the flocculant concentration increases, the particle size generally increases. As the flocculant concentration decreases, the particle size also decreases. Similarly, the flocculant concentration, when the degree of dissociation of the monomer unit having an ionic dissociative group of the polymer particles is constant, the particle size becomes larger and smaller when the addition concentration of the organic solvent infinitely soluble in water is increased. And the particle size becomes smaller. Furthermore, when the degree of dissociation of the monomer unit having an ionic dissociative group of the polymer particles is changed, the particle size becomes smaller as the degree of dissociation increases, and the particle size of the formed particles increases when the degree of dissociation is smaller.

That is, in the present invention, a desired particle size can be obtained by appropriately changing the above three factors. Further, by the action of these three factors, particles having a very narrow particle size distribution can be obtained.

[Production Method] The toner of the present invention is not limited to this. Typically, a required amount of a metal salt or an aqueous solution of a metal salt is added to a polymer fine particle dispersion under stirring. . Further, a basic step is to add an organic solvent which is infinitely soluble in water and heat the polymer fine particles at a temperature of -5 ° C to + 50 ° C of Tg of the polymer fine particles. However, the order of addition of each additive is not particularly defined, and the production method is not particularly limited thereto.

For example, when the heating temperature is constant, the shape approaches a true sphere as the heating time becomes longer. In addition, when the heating temperature is increased, the speed of forming a true sphere increases.

Several coefficients have been proposed as indices representing the shape. For example, there are the following values as the degree of non-sphericity.

Degree of non-sphericity = (BET specific surface area of non-spherical particles) / (surface area calculated as a true sphere from average particle diameter of non-spherical particles) The non-spherical particles of the present invention have the above-mentioned degree of non-sphericity. It is preferably 1.1 or more, and particularly, the degree of non-sphericity is 1.1 to 5.0, more preferably 1.2 to 3.5.

[Electrostatic Image Developing Toner] Since the non-spherical particles of the present invention are used as an electrostatic image developing toner, the average particle size is 3 to 25 μm, particularly preferably 5 to 15 μm.
Is good. In particular, the toner particles of the present invention have a small particle size distribution and do not change even if they have a small particle size, and can be obtained in a high yield without any post-processing such as a classification operation. Preferred for use as

The above-mentioned non-spherical particles can be used alone as a toner. However, silica, titanium oxide,
Aluminum oxide and their hydrophobized products can be used in combination. The fluidizing agent is 0.01 to 100 parts by weight of the toner.
Preferably, 20 parts by weight are added, more preferably 0.1 to 10 parts by weight.

Further, as a lubricant, cadmium, barium, nickel, cobalt, strontium, stearic acid,
Copper, magnesium, calcium salts, etc., zinc, manganese, iron, cobalt, copper, lead, magnesium salts of oleic acid, zinc, cobalt, copper, magnesium, silicon, calcium salts of palmitic acid, zinc, cobalt, calcium of linoleic acid Metal salts of higher fatty acids such as salts, zinc and cadmium salts of ricinoleic acid, lead salts of caprylic acid and lead salts of caproic acid. These are added as needed.

[Image Forming Method Used in the Present Invention] The image forming method of the present invention is not limited to this, but an example of the image forming method of the present invention will be described below.

FIG. 1 is a sectional view showing an example of a developing device (developing device) used in the image forming method according to the present invention. In this figure, reference numeral 41 denotes a developing sleeve which is a developer carrying body having a fixed magnet 42 therein, 46 denotes a regulating rod which is a developer carrying amount regulating member, 47 denotes a scraper which is a developer scraping member, and 48 denotes a scraper which is a developer scraping member. A stirring roller as a developer stirring member, 49 is a casing of a developing device, 50 is a two-component developer composed of toner T and carrier C (in the present invention, it is not necessary to add a carrier, and one-component development of toner only is performed. , 51 is a power supply as a bias applying means, 10 is a photosensitive drum as an image forming body having a photosensitive layer 12 formed on a conductive substrate 11, and D1 is the photosensitive drum 1
0 and the closest distance between the developing sleeve 41 and 10 in FIG.
Indicates the rotation direction of the photosensitive drum 10 and the developing sleeve 41.

The developing sleeve 41 is made of, for example, aluminum,
It is a cylinder of 0.5 to 3 cm in diameter made of non-magnetic and conductive metal such as stainless steel, and has a surface roughness (Rz) of 1 to 3.
It is processed to be 30 μm. Inside the developing sleeve 41, 4 to 12 magnetized to the N pole or the S pole
A magnet body 42 such as a columnar or split chopstick-shaped (column-shaped) aggregate having magnetic poles is fixedly provided, and the developing sleeve 41 is rotatable with respect to the magnet body 42.

The casing 49 is a casing made of, for example, an insulating resin such as acryl or polycarbonate. Inside the casing 49, the developing sleeve 41 including the fixed magnet body 42, the supply roller 45, and the scraper 4 are provided.
7 and the stirring roller 48 are disposed,
A regulating rod 46 is disposed at the outlet of the control rod.

A two-component developer 50 composed of toner T and carrier C is stored inside the casing 49. The two-component developer 50 is stirred and mixed by the stirring roller 48 and is supplied by the supply roller 45 and adheres to the developing sleeve 41 to form a magnetic brush. The magnetic brush is transported while the transport amount is regulated by the regulating rod 46 as the developing sleeve 41 rotates.

An AC voltage having a DC component from the power supply 51 is applied to the developing sleeve 41.
A strong oscillating electric field is formed in the gap between the photosensitive drum 10 and the photosensitive drum 10. The strong oscillating electric field causes the toner to fly away from the carrier and generate a toner cloud. As a result, a flight toward the latent image on the photosensitive drum 10 occurs, and a toner image is formed on the photosensitive drum 10.

FIG. 2 is a sectional view of an apparatus for explaining an example of the image forming method of the present invention. In the figure, 10 is a photosensitive drum as an image forming body, 20 is a scorotron charger as charging means, 25 is an image reading section, 30 is an image writing section using a laser beam as exposure means, 40
Reference numerals A, 40B, 40C and 40D denote the developing devices shown in FIG.
A paper feed unit including a paper feed roller 61 and a second paper feed roller 62; 70, a corona charger for transfer as a transfer unit; 75, a corona charger for separation as a separation unit;
5 is a fixing unit, 90 is a cleaning device provided with a cleaning blade 91, and 95 is a pre-charging exposure lamp. Arrows in the drawing indicate the rotation direction of the photosensitive drum 10.

The basic operation of the multicolor image forming process according to this embodiment is as follows. First, a copy start command is sent from an operation unit (not shown) to a control unit (not shown),
Starts spinning. According to the rotation of the photosensitive drum 10,
The peripheral surface is uniformly charged by the scorotron charger 20. In the image reading unit 25, optical information from the document is converted into an electric signal. The electric signal is subjected to image processing and then input to the image writing unit 30. The charged photosensitive drum 10 is irradiated with a laser beam from the image writing unit 30 to form a latent image on the photosensitive drum 10. The latent image on the photosensitive drum 10 is developed by any of the developing devices 40A, 40B, 40C, and 40D, and a toner image is formed on the photosensitive drum 10.

The photosensitive drum 1 on which the toner image is formed
0 is uniformly charged again by the scorotron charger 20 and is irradiated with a laser beam by the image writing section 30 to form the next latent image. The latent images on the photosensitive drum 10 are stored in the developing devices 40A, 40B, 40C.
Or 40D, and the next toner image is superimposed on the photosensitive drum 10.

In this embodiment, the above-described latent image forming step and developing step are repeated four times,
The color toner images are superimposed.

The paper feed unit 60 stores transfer paper as a transfer material (in the present invention, any transfer paper that can transfer an unfixed toner image can be used without particular limitation).
The first paper feed roller 61 and the second paper feed roller 62 send the toner image to the transfer corona charger 70 in synchronization with the toner image superimposed on the photosensitive drum 10. The toner image superimposed on the photosensitive drum 10 is transferred onto recording paper by the corona charger for transfer, and the transfer paper is separated from the photosensitive drum 10 by the corona charger 75 for separation. The transfer paper onto which the toner image has been transferred is conveyed to the fixing unit 85 via the conveying unit 80, and is fixed to the pressure-sensitive fixing unit and then discharged out of the apparatus.

On the other hand, the toner remaining on the photosensitive drum 10 without being transferred to the transfer paper is cleaned by a cleaning blade 9 pressed against the photosensitive drum 10 in a timely manner.
1 is scraped off by a cleaning device 90 having
After the residual potential is removed by the pre-charging exposure lamp 95,
Enter the next image forming process.

In the development in the present invention, non-contact development is usually performed by applying an AC voltage. However, the present invention is not limited to these, and can be used for contact development. Further, it is not necessary to form a multicolor image as described above, and the method is also used as a monochrome image forming method.

[0080]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

[Production of emulsified dispersion of fixing property improving agent] 240 g of low molecular weight polypropylene (number average molecular weight = 3300,
The molecular weight distribution (Mw / Mn) was modified according to a conventional method using maleic anhydride (11.4 g), the melt viscosity was measured, and then the fixability improver of the present invention was dissolved in hydrochloric acid-containing nonylphenoxyethanol ( Ethoxy unit added mole number = 20, HLB = 16.0) was added to 560 g of an aqueous solution, and the pH was adjusted to 9 with potassium hydroxide.
The temperature was raised and emulsified and dispersed above the softening point of the modified polypropylene. The particle diameter of this modified polypropylene dispersion was measured by a light scattering electrophoresis particle size analyzer (ELS-800: manufactured by Otsuka Electronics Co., Ltd.), and as a result, it was 182 nm. This emulsified dispersion of fixability improver is referred to as emulsified dispersion of fixer.

[Preparation of Pigment Dispersion 1] 267 g of carbon black (Legal 330R, manufactured by Cabot Corporation) was added to 5000 ml of ion-exchanged water and sodium dodecyl sulfate 12 was added.
2.75 g was added, and the mixture was dispersed using an ultrasonic homogenizer and a pressure disperser. The average particle size of carbon black in the dispersion was measured by a light scattering electrophoresis particle size analyzer (ELS-8).
00: Otsuka Electronics Co., Ltd.).

[Production of Pigment Dispersions 2, 3, 4] Instead of carbon black of Pigment Dispersion 1, C.I.
I. Pigment Yellow-17, C.I. I. Pigment Red-122, C.I. I. Pigment Blue-15: 3, except that Pigment Blue-15: 3 was used. The average particle size of the pigment in the dispersion was measured using a light scattering electrophoretic particle size analyzer (ELS-800: manufactured by Otsuka Electronics Co., Ltd.).
m.

[Synthesis of Toner Suspension 1 for Developing Electrostatic Image]
20 l with cooling tube, thermometer, stirrer and nitrogen inlet tube
426 ml of Pigment Dispersion 1, 3200 ml of distilled water, 421.4 g of styrene, 80 g of n-butyl acrylate, 32 g of methacrylic acid, 0.6 g of tert-dodecyl mercaptan, and 106 g of an emulsifying dispersion of fixing improver were added to a four-necked flask. Then, the mixture was stirred at a stirring speed of 210 rpm and heated to a temperature of 70 ° C. while flowing nitrogen. While maintaining the internal temperature at 70 ° C, potassium persulfate 8.2
g of the polymerization initiator dissolved in 660 ml of pure water was added, and polymerization was carried out for 3 hours while maintaining an internal temperature of 70 ° C. and a stirring speed of 210 rpm under a nitrogen stream. After the polymerization, the internal temperature was lowered to room temperature, and then 854 ml of Pigment Dispersion 1, 6400 ml of distilled water, 842 g of styrene, 160 g of n-butyl acrylate, 64 g of methacrylic acid, 36.6 g of tert-dodecyl mercaptan, and 36.6 g of a fixing improver 212 g of the emulsified dispersion was added, the mixture was stirred at a stirring speed of 210 rpm, and the flask was heated to 70 ° C. while flowing nitrogen. While maintaining the internal temperature at 70 ° C, potassium persulfate 1
An aqueous solution of a polymerization initiator in which 6.4 g was dissolved in 1320 ml of pure water was added, and the mixture was stirred at an internal temperature of 70 ° C. and a stirring speed of 210 under a nitrogen stream.
Polymerization was performed for 3 hours while maintaining the rpm. After completion of the polymerization, the internal temperature was lowered to room temperature.

Further, 10 l of this colorant-containing fine particle dispersion was adjusted to pH = 9.8 using 5N sodium hydroxide, and then 20 l of a dispersion apparatus equipped with a stirrer, a cooling pipe, and a temperature sensor.
And stirred at 140 rpm.
To this was added an aqueous electrolyte solution obtained by dissolving 473.4 g of sodium chloride in 1400 ml of distilled water, and 898 ml of isopropyl alcohol and 34 parts of Triton X-100 were added.
g was dissolved in 400 ml of distilled water, and a nonionic surfactant aqueous solution was sequentially added. Then, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.

[Synthesis of Toner Suspension 2 for Developing Electrostatic Image]
10 l with cooling tube, thermometer, stirrer, nitrogen inlet tube
213 ml of Pigment Dispersion 2, 1600 ml of distilled water, 210.7 g of styrene, 40 g of n-butyl acrylate, 16 g of methacrylic acid, 0.3 g of tert-dodecyl mercaptan, and 53 g of emulsifying dispersion of fixing improver Then, the flask was stirred at a stirring speed of 250 rpm and heated to 70 ° C. while flowing nitrogen. While maintaining the internal temperature at 70 ° C, potassium persulfate 4.1
g of the polymerization initiator dissolved in 330 ml of pure water was added, and polymerization was carried out for 3 hours in a nitrogen stream while maintaining an internal temperature of 70 ° C. and a stirring speed of 250 rpm. After the polymerization, the internal temperature was lowered to room temperature.
27 ml, distilled water 3200 ml, styrene 421 g, n
-Butyl acrylate 80 g, methacrylic acid 32 g, t
18.3 g of ert-dodecyl mercaptan and 106 g of a fixing improver emulsified dispersion were added. Stirring speed 250r
The temperature inside the flask was set to 70 ° C. while stirring at pm and flowing nitrogen.
Until heated. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 8.2 g of potassium persulfate was dissolved in 660 ml of pure water was added, and polymerization was performed for 3 hours while maintaining the internal temperature at 70 ° C. and the stirring speed at 250 rpm under a nitrogen stream. Was done. After completion of the polymerization, the internal temperature was lowered to room temperature.

Further, this colorant-containing fine particle dispersion liquid 2500
After adjusting the pH to 9.8 using 5N sodium hydroxide, the mixture was equipped with a stirrer, a cooling pipe, and a temperature sensor.
The mixture was placed in a 000 ml four-necked flask and stirred at 210 rpm. Here, 147.3 g of sodium chloride was added to 70
An aqueous electrolyte solution dissolved in 0 ml of distilled water was added, and 449 ml of isopropyl alcohol and Triton X-10 were added.
After sequentially adding a nonionic surfactant aqueous solution obtained by dissolving 0. 17 g in 200 ml of distilled water, the internal temperature was raised to 85 ° C and the reaction was carried out for 6 hours.

[Synthesis of Toner Suspension 3 for Developing Electrostatic Image]
The toner suspension 2 for electrostatic image development was prepared in the same manner as the synthesis of the toner suspension 2 for electrostatic image development, except that the pigment dispersion 2 was changed to the pigment dispersion 3.

[Synthesis of Toner Suspension 4 for Developing Electrostatic Charge Image]
The toner suspension 2 for electrostatic image development was prepared in the same manner as the synthesis of the toner suspension 2 for electrostatic image development, except that the pigment dispersion 2 was changed to the pigment dispersion 4.

[Production of Toner 1 for Developing an Electrostatic Image] After filtering 2500 ml of the toner suspension 1 for developing an electrostatic image, distilled water was added to redisperse the solution, and the pH was adjusted using 5N sodium hydroxide.
= 13 and washing with water and filtration were repeated 7 times to remove the surfactant and the electrolyte. After the washing, the resultant was dried at a drying temperature of 38 ° C. under normal pressure to obtain a toner 1 for developing an electrostatic image. After drying, the molecular weight was measured using gel permeation chromatography (hereinafter abbreviated as GPC), and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results.

[Production of Toner 2 for Developing Electrostatic Image] After filtering 2500 ml of the toner suspension 1 for developing an electrostatic image, distilled water was added to redisperse the solution, and the pH was adjusted using 5N sodium hydroxide.
= 13 and washing with water and filtration were repeated 7 times to remove the surfactant and the electrolyte. After the washing, the resultant was dried at a drying temperature of 43 ° C. under normal pressure to obtain a toner 2 for electrostatic image development. After drying, G
The molecular weight was measured using a PC, and the particle size was measured using a Coulter counter. Further, a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation) was used for the measurement.
The pore volume ratio having a pore diameter of 1 μm or less was determined. Table 1 shows the measurement results.

[Preparation of Toner 3 for Developing Electrostatic Image] After filtering 2,500 ml of the toner suspension 1 for developing an electrostatic image, distilled water was added to redisperse the solution, and pH was adjusted using 5N sodium hydroxide.
= 13 and methanol / water = 5/5 as a washing solvent
Washing and filtration were repeated 7 times using a mixed solvent of to remove the surfactant and the electrolyte. After the washing, the resultant was dried at a drying temperature of 38 ° C. under normal pressure to obtain a toner 3 for electrostatic image development. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation).
Table 1 shows the measurement results.

[Manufacture of Toner 4 for Developing Electrostatic Image] After filtering 2500 ml of the toner suspension 1 for developing an electrostatic image, distilled water was added to redisperse the solution, and pH was adjusted using 5N sodium hydroxide.
= 13 and methanol / water = 5/5 as a washing solvent
Washing and filtration were repeated 7 times using a mixed solvent of to remove the surfactant and the electrolyte. After the washing, the toner was dried at a drying temperature of 38 ° C. under reduced pressure (100 mmHg or less) to obtain a toner 4 for electrostatic image development. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Also, a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320
Using the shape (manufactured by Shimadzu Corporation), the pore volume ratio having a pore diameter of 0.1 μm or less was determined. Table 1 shows the measurement results.

[Production of Toner 5 for Developing Electrostatic Image] Production of Toner 1 for Developing Electrostatic Image, except that Toner Suspension 2 for Developing Electrostatic Image was used instead of Toner Suspension 1 for Developing Electrostatic Image. The same operation as in the example was performed to obtain a toner 5 for developing an electrostatic image. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results.

[Production of electrostatic image developing toner 6] Production of electrostatic image developing toner 1 except that electrostatic image developing toner suspension 3 was used instead of electrostatic image developing toner suspension 1. By performing the same operation as in the example, a toner 6 for electrostatic image development was obtained. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results.

[Production of Toner 7 for Developing Electrostatic Image] Production of Toner 1 for Developing Electrostatic Image, except that Toner Suspension 4 for Developing Electrostatic Image was used instead of Toner Suspension 1 for Developing Electrostatic Image. By performing the same operation as in the example, a toner 7 for developing an electrostatic image was obtained. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, Pore Sizer 9320 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results.

[Production of comparative electrostatic image developing toner 1] 2500 ml of the electrostatic image developing toner suspension 1 was filtered,
Distilled water was added for redispersion, the pH was adjusted to 13 using 5N sodium hydroxide, and washing and filtration were repeated seven times using methanol as a washing solvent to remove the surfactant and the electrolyte. After the washing, the resultant was dried at a drying temperature of 38 ° C. to obtain a comparative electrostatic image developing toner 1. After drying, the molecular weight was measured using GPC, and the particle size was measured using a Coulter counter.
In addition, mercury intrusion type pore distribution measuring device Pore Sizer 932
The pore volume ratio having a pore diameter of 0.1 μm or less was determined using Form 0 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results. [Production of comparative electrostatic image developing toner 2] 2500 ml of the electrostatic image developing toner suspension 1 was filtered, redispersed by adding distilled water, adjusted to pH = 13 using 5N sodium hydroxide, and washed. Washing and filtration were repeated seven times using methanol as a solvent to remove the surfactant and the electrolyte. After washing, drying was performed at a drying temperature of 38 ° C. under reduced pressure (100 mmHg or less) to obtain a comparative electrostatic image developing toner 2. After drying,
The molecular weight was measured using GPC, and the particle size was measured using a Coulter counter. Further, the volume ratio of pores having a pore diameter of 0.1 μm or less was determined using a mercury intrusion-type pore distribution measuring apparatus, pore sizer Model 9320 (manufactured by Shimadzu Corporation). Table 1 shows the measurement results.

[0098]

[Table 1]

Evaluation Using the electrostatic image developing toners 1 to 7 and the comparative electrostatic image developing toners 1 and 2 of the present invention, 2 parts by weight of hydrophobic silica and 1 part by weight of titanium oxide were added to 100 parts by weight of these. 5 parts by weight of this externally added toner and a methyl methacrylate / styrene copolymer (MAA / St = 7/3 weight ratio)
Particles (carrier, average particle size 6)
0 μm) 95 parts by weight were mixed to prepare Developers 1 to 7 of the present invention and Comparative Developers 1 and 2.

Using the above developer, a long run was carried out using an apparatus modified from Konica 9028, a color copying machine manufactured by Konica.

The conditions are as follows.

As the photoreceptor, a laminated organic photoreceptor was used.

Photoconductor surface potential = -550 V DC bias = -250 V AC bias = Vp-p: -50 to -450 V Alternating electric field frequency = 1800 Hz Dsd (distance between photosensitive member and developing sleeve) = 300 μm Pressing force = 10 gf / mm Pressing control rod = SUS416 (made of magnetic stainless steel) / diameter 3 mm Developer layer thickness = 150 μm Developing sleeve = 20 mm Environmental conditions were normal temperature and low humidity (25 ° C / 30% RH), and the pixel rate was 1% continuously. The image was printed on 10,000 sheets.
The charge amount of the toner at the start and after printing 10,000 sheets was measured by a blow-off method. Table 2 shows the measurement results. As a result, in a toner in which the total volume of the pores having a pore diameter of 0.1 μm or less is 30% or less of the total pore volume on the surface of the toner particles, the charge amount stably changes at the start and after printing 10,000 sheets. You can see that it is.

[0104]

[Table 2]

As is evident from Table 2, it can be seen that in the present invention, the charge amount after printing 10,000 sheets is stable.

[0106]

According to the present invention, it is possible to provide a toner whose charge amount does not become unstable even after long-term use, and an image forming method using the same.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a developing device according to the present invention.

FIG. 2 is a cross-sectional view of an apparatus showing an example of the image forming method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum (image forming body) 11 conductive substrate 12 photosensitive layer 20 scorotron charger 25 image reading unit 30 image writing unit 40A, 40B, 40C, 40D developing device (developing device) 41 developing sleeve (developer conveying member) 42 magnet body 45 supply roller 46 regulating rod 47 scraper 48 stirring roller 49 casing 50 two-component developer 51 power supply 60 paper supply unit 61 first paper supply roller 62 second paper supply roller 70 transfer corona charger 75 separation corona charge Container 80 Conveying Unit 85 Fixing Unit 90 Cleaning Device 91 Cleaning Blade 95 Pre-Charge Exposure Lamp

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomie Kitani 1 Konica Stock Company, Sakuracho, Hino City, Tokyo (72) Inventor Mikio Kamiyama 1 Konica Stock Company, Sakuracho, Hino City, Tokyo

Claims (6)

[Claims] 1. A toner for developing an electrostatic charge image in which a plurality of polymer fine particles are associated with each other.
A toner for developing an electrostatic charge image, wherein the total volume of pores having a pore diameter of not more than 30 μm is 30% or less of the total pore volume on the surface of the toner particles. 2. The toner according to claim 1, wherein the polymer fine particles contain a monomer unit having an ionic dissociating group. 3. The electrostatic charge according to claim 1, wherein the polymer fine particles contain a monomer unit having an ionic dissociating group, and a part or all of the ionic dissociating group is in a dissociated state. Image developing toner. 4. An image forming method in which an electrostatic charge image formed on a photoreceptor is developed with a toner to form a toner image.
An image forming method, wherein the toner is the toner according to claim 1. 5. An image forming method for transferring a toner image formed on a photoreceptor onto a transfer material, wherein the toner is the toner according to claim 1. 6. An image forming method for transferring a toner image formed on a photoreceptor onto a transfer material and then cleaning and removing the toner remaining on the photoreceptor, wherein the toner is the toner according to claim 1. An image forming method comprising: