JP2921582B2 - Toner for developing electrostatic images - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a toner for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like. Is related to a binder resin.

[Conventional technology]

Generally, in an electrophotographic method or an electrostatic recording method, a toner supply roller such as a developing sleeve is used to develop an electrostatic latent image formed on a latent image carrier made of a photoconductive photoreceptor or a dielectric. After the toner image is transferred to a transfer material such as paper after development using a toner that has been thinned by a blade or the like, and is appropriately charged and finely powdered, if necessary, it is fixed by heating pressure, solvent vapor, or the like. A copy is obtained.

As a developing method applied to these electrophotographic methods and the like,
Broadly, there are a dry development method and a wet development method. The former is further divided into a method using a two-component developer and a method using a one-component developer. Those belonging to the two-component development method include:
Depending on the type of carrier that carries the toner, there are a magnet brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, and the like.

In addition, those belonging to the one-component developing method include a powder cloud method in which toner particles are used in a spray state, and a contact developing method in which toner particles are brought into direct contact with an electrostatic latent image surface for development (contact development or toner development). ), A jumping developing method in which the toner particles are charged and fly toward the latent image surface by an electric field of the electrostatic latent image without directly contacting the toner particles with the electrostatic latent image surface. For example, there is a magnedry method in which development is performed by contacting the surface of the latent image.

A low molecular weight polyethylene or polypropylene is mixed as a releasing agent in the toner applied to these developing methods in order to improve the offset property in a fixing portion. In this case, low-molecular-weight polyethylene or polypropylene has poor compatibility with polystyrene used as a binder resin, so that phase separation occurs during kneading. At the interface due to phase separation, destruction easily occurs due to the application of a mechanical force, and the toner is developed into fine powder. For example, at the contact surface between the photoconductive photoreceptor and the paper, or at the contact surface between the developing sleeve (developing roller) and the blade, and further at the contact surface between the developing sleeve and the photoconductive photoreceptor, the toner is pulverized. Development occurs.

For example, in the case of the contact developing method, the finely divided toner adheres to the developing sleeve and causes a fusing phenomenon with time, and filming occurs on the developing sleeve. When the filming phenomenon is observed on the developing sleeve, the thickness of the thinned toner layer becomes non-uniform, which causes a non-uniform distribution of the charge amount during the development of the electrostatic latent image. This results in non-uniform toner adhesion per unit area on the sleeve, which results in shading on the copy, which is very problematic on the image. The pulverization of the toner caused by the brittleness of the toner particles means that the toner is easily pulverized by mechanical force, which is preferable from the viewpoint of the productivity of the toner. In order to avoid such a filming phenomenon, it is conceivable to use a polymer having a high molecular weight. However, when heat fixing of an image which is usually performed in the final step of copying or printing is taken into consideration, the fixing temperature is increased and the fixing is performed. In this case, a larger amount of heat is required, which is not preferable from the viewpoint of energy saving or downsizing of hardware devices. Further, for the purpose of solving this phenomenon, it has been proposed to add a small amount of a plasticizer to the toner.However, there is a problem that the free flowing property of the toner is impaired and the carrier is contaminated. Not successful. On the other hand, if the toner is too hard, mechanical pulverization becomes impossible, or the toner cannot be sufficiently dispersed by kneading.

Heretofore, for the reasons described above, relatively low molecular weight polystyrene or styrene-
A butyl methacrylate copolymer or the like has been used as a binder resin for a toner. However, in the case of a device such as a laser printer, which requires an electrophotographic system and is maintenance-free, a relatively low molecular weight polystyrene or styrene-butyl methacrylate copolymer is not sufficiently hard, and furthermore has a high hardness. It has been found that a material with a high density is necessary. In addition, this type of binder resin has insufficient properties in thermal fixing by a hot roll, which is widely used at present, so that the toner binder resin is melted by heat and adherence to paper or the like is good. However, there is an offset phenomenon to the heat roller.

Further, in order to suppress filming on the developing roller and the photoconductor and spent on the carrier, a fluidization accelerator is often used. For example, Japanese Patent Application Laid-Open No. 47-36405,
No. 7-36830 discloses the use of metal soap.
No. 41, JP-A-53-147541 discloses the use of a fluorine compound, JP-A-54-8534 discloses the use of a nonionic surfactant, and JP-A-56-62256 discloses the use of a surface active agent. The use of hydrophobized silica has been proposed in each case.

Further, Japanese Patent Application Laid-Open No. 56-66856 discloses that particles harder than the toner can be buried in the toner surface.
In JP-A-59-131943, an ion-exchange resin is contained in a binder resin, and in JP-A-59-131943, oxidized polyethylene is used as a mold release agent to exhibit a mold release effect while having compatibility with the binder resin. Japanese Patent Application Laid-Open No. Sho 56-197048 discloses that a silicone oil is contained in a binder resin, and Japanese Patent Application Laid-Open No. Sho 59-220748 discloses that wax fine particles are externally added to a toner. In Japanese Patent Application Laid-Open No. 138565/1989, it is disclosed that Kobon Black is externally added to lower the toner resistance.
No. 60-186853, JP-A-60-1868454, JP-A-60-18685
5, JP-A-60-186857, JP-A-60-186858, JP-A-60-186860, JP-A-60-186861, JP-A-60-1868
No. 62, JP-A-60-186863, JP-A-60-186864, JP-A-60-186865 and JP-A-60-186866, it is possible to add polymer fine particles externally. In JP-A-61-99164, it has been proposed to externally add an abrasive (SiC, SiN).

[Problems to be solved by the invention]

However, the effect of suppressing the filming on the developing roller and the photoconductor and the spent on the carrier is not yet sufficient only by using the additive as described above, and the toner formed by the polymer which is the main component of the toner is still not formed. It is considered that the best method is to avoid filming and spent by improving the higher-order structure.

Accordingly, an object of the present invention is to suppress the toner particles from being pulverized on the photoconductor and the developing sleeve, and to reduce the development sleeve and the photoconductor by frictional heat between the developing sleeve and the photoconductor or between the developing sleeve and the blade. An electrostatic image developing toner which suppresses filming on the body, spent on a carrier, and sticking to a blade, and provides a good copy image with the above-described suppressing effect permanently, and image formation by a one-component developing method using the same. It is to provide a method.

[Means for solving the problem]

The present inventors have conducted intensive studies and found that a toner having a specific sea-island structure is suitable for the above purpose.
The present invention has been completed.

That is, according to the present invention, in a toner comprising at least a binder resin and a colorant, a higher-order structure in a polymer blend system when a cross section of the toner is observed with a transmission electron microscope is a sea-island structure formed by a base polymer and polypropylene. The maximum diameter in the major axis direction of the islands formed by polypropylene is 200 to 3000 °, the average distance between the islands in the distribution of the islands is 1 μm or less,
In addition, the area ratio of islands within an arbitrary area of 1 μm × 1 μm on the toner surface is 5 to 5% when measured by an image processing apparatus.
60% of the toner for developing an electrostatic image is provided.

The toner is generally composed of a plurality of polymers, and the polymers are mixed at a micron level by melt-kneading. The above state is clear by dyeing the cross section of the toner and observing it with a transmission electron microscope (TEM). In addition, low-molecular-weight polypropylene, low-molecular-weight polyethylene, wax, and the like are mixed with the oil-less toner in order to impart releasability to prevent offset during normal fixing. Release agents such as these low molecular weight polypropylene,
By receiving the thermal energy from the fixing roller at the time of fixing, an effect of preventing the toner from oozing out of the toner and being offset to the fixing roller is exerted.

On the other hand, a phenomenon is observed in which the toner adheres to the developing roller or the photoconductor over time, causing so-called filming. As a result of a surface analysis, it was found that the filming substance was mainly composed of low-molecular-weight polypropylene or low-molecular-weight polypropylene having a releasing action present in the toner. Thus, when a cross section of the toner where filming easily occurs was observed by TEM, the higher-order structure in the polymer blend system was a sea-island structure formed by the base polymer and polypropylene, and the length of the island-like portion formed by polypropylene was longer. The maximum diameter in the axial direction is 1.7 μm, the distance between islands in the distribution of the islands is 1.2 μm or more, and 1 × 1
It was found that the area ratio of the island portion within the area of μm was 0% or 70% or more when measured by an image processing apparatus.

In other words, the low-molecular-weight release agent present on the toner surface is an island in the sea-island structure in the higher-order structure in the polymer, and filming is likely to occur as the size of the island increases. Can be In other words, as the size of the island-shaped low-molecular-weight release agent increases, the low-molecular-weight release agent easily comes out of the toner surface due to frictional heat generated by the toner supply member when the toner adheres to the developing roller. Become. As a result, the low molecular weight release agent is thinned on the developing roller, and a film is formed. It is considered that the state of the low molecular weight release agent component in the polymer is governed by the change in viscosity due to the change in molecular weight during melt kneading.

In addition, the maximum diameter of the island-shaped portion in the TEM observation of the toner is 1.7
When the particle size is extremely large, such as μm or more, the toner tends to be easily pulverized on the developing roller. It is presumed that this phenomenon occurs due to insufficient interfacial separation between the main polymer and the low molecular weight release agent component due to insufficient formation of the polymer alloy in the toner.

Accordingly, the maximum diameter in the major axis direction of the island portion in the TEM observation of the toner cross section, the distribution of the island portion, and the area ratio of the island portion within an arbitrary area are measures of the filming property of the toner. When the value is within the above range,
The toner is hardly pulverized on the developing roller, and filming on the developing roller and fogging during development are reduced.

If the maximum diameter in the major axis direction of the islands formed by the polypropylene in the toner cross section is less than 200 mm, the low molecular weight release agent component in the polymer alloy will have an almost completely regular phase structure like a block polymer. As a result, the polypropylene alloy does not preferentially elute on the surface of the toner at the time of fixing, and no releasing effect is exhibited. As a result, an offset phenomenon occurs at the time of fixing.

Further, if the maximum diameter in the major axis direction of the island portion formed by the polypropylene in the toner cross section exceeds 3000 mm, the interaction force of the interface in the phase separation state between the main polymer and the polypropylene is reduced, and as a result, on the developing roller By friction with the toner supply member, toner layer regulation member or photoconductor,
Fine powdering of the toner occurs, and filming on the developing roller and fogging during development are likely to occur.

If the distance between the islands in the distribution of the islands exceeds 1 μm, the distribution of polypropylene becomes polarized, so that polypropylene tends to be easily eluted.

On the other hand, if the area ratio of the island portion within an arbitrary area of 1 μm × 1 μm on the toner surface is less than 5% when measured by an image processing apparatus, offset development occurs at the time of fixing, which is not preferable. When the ratio exceeds the above range, the film is melted on the developing roller or the photosensitive member to cause a filming phenomenon, so that the intended object of the present invention cannot be achieved.

In the present invention, a high-resolution transmission electron microscope manufactured by Hitachi, Ltd. was used for TEM measurement, and Luzex III manufactured by Nireco was used as an image processing apparatus.

The binder resin used in the toner of the present invention is not limited to the above-mentioned polystyrene and styrene-butyl methacrylate copolymer, but those conventionally used as binder resins for toner are used. Specific examples of the binder resin monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, and p-methylstyrene.
-N-butylstyrene, p-tert-butylstyrene, p
-N-hexylstyrene, pn-octylstyrene,
pn-nonylstyrene, pn-decylstyrene, p
-N-dodecylstyrene, p-methoxystyrene, p-
Styrenes such as phenylstyrene, p-chlorostyrene, and 3,4-dicrosthylene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride Vinyl esters such as vinyl acetate and vinyl propionate; methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid;
α-methylene aliphatic monocarboxylic acid esters such as n-butyl; vinyl ethers such as vinyl methyl ether;
Examples thereof include vinyl ketones such as vinyl methyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, and N-vinyl pyrrolidone. These monomers can be used alone or in combination of two or more.

Further, as the monomer for forming the polycondensation type resin, ethylene glycol, triethylene glycol, 1,
Polyhydric alcohols such as 2-propylene glycol, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene oxidized bisphenol A; polyhydric amines such as ethylenediamine, tetramethylenediamine, piperazine; maleic acid;
Fumaric acid, mesaconic acid, citraconic acid, adipic acid,
Examples thereof include malonic acid or esters thereof with acid anhydrides or lower alcohols.

Incidentally, the toner of the present invention contains a colorant,
If desired, a charge control agent or the like can be contained.

As the colorant used in the toner of the present invention, all pigments and dyes conventionally used as colorants for toner are applied. Specifically, carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, calco oil blue, Dupont oil red,
Quinoline Yellow, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Hansa Yellow G, Rhodamine 6C Lake, Chrome Yellow, Quinacridone, Benzidine Yellow, Malachite Green, Malachite Green Hexalate, Oil Black, Azo Oil Black, Rose Bengal, Monoazo Dye Pigment And disazo dyes and pigments, trisazo dyes and pigments, and mixtures thereof.

In addition, as the charge control agent, there are nigrosine-based dyes, quaternary ammonium salts, basic dyes, polymers having an amino acid content, and the like, which impart positive polarity to the toner.
In addition, examples of materials that impart a negative polarity include chromium-containing monoazo dyes, chloro-containing organic dyes, and metal salts of salicylic acid derivatives.

Further, a fluidizing agent may be contained in the toner of the present invention. As the fluidizing agent, for example, an inorganic oxide such as SiO ₂ or TiO ₂ having a surface subjected to hydrophobic treatment, inorganic fine particles such as SiC,
Examples include metal soaps such as zinc stearate.

The toner of the present invention is particularly useful for forming an image by one-component development in electrophotography. Next, the image forming method of the present invention will be described.

The image forming method according to the present invention is directed to an image forming method using a one-component developing method in electrophotography in which a thinned toner is supplied to a latent image carrier to develop a latent image. Is used.
In addition, the toner thin layer is usually provided with a toner conveying member, a toner layer thickness regulating member and a toner supplying member, and the toner supplying member and the toner conveying member and the toner layer thickness regulating member and the toner conveying member respectively come into contact with each other. This is performed using a device.

The image forming method of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic sectional view of an example of a developing device using a non-magnetic one-component toner useful for carrying out the method of the present invention.
In FIG. 1, toner 6 of the present invention contained in a toner tank 7 is forcibly brought to a toner supply member (sponge roller) 4 by a stirring blade (toner supply auxiliary member) 5, and the toner is supplied to the toner supply member. 4 is supplied. Then, the toner taken in the toner supply member 4 is carried to the toner conveying member (developing roller) 2 by the rotation of the toner supply member 4 in the direction of the arrow, and is rubbed and electrostatically or physically attracted. The toner conveying member 2 rotates strongly in the direction of the arrow, and a uniform toner thin layer is formed by the toner layer thickness regulating member (elastic blade) 3 made of steel, and the toner is charged by friction. Thereafter, the latent image is transported to the surface of the electrostatic latent image carrier 1 which is in contact with or in proximity to the toner conveying member 2, and the latent image is developed. The electrostatic latent image is minus 800 V on the organic photoreceptor
After DC charging, it is exposed, forms a latent image and is developed. The developing device suitable for the toner of the present invention is not limited to the above.

In such an electrophotographic image forming method according to the one-component developing method, if finely divided toner adheres to the developing sleeve and filming has a great effect on the formation of a uniform thin layer of toner, the present invention The toner is prevented from being pulverized on the photoconductive photoconductor and the developing sleeve, and as a result, filming on the developing sleeve and the photoconductive photoconductor is suppressed. The method of the present invention provides a high quality image over a long period of time.

〔Example〕

EXAMPLES Hereinafter, examples of the present invention will be specifically described, but the present invention is not limited to these examples. Parts represent parts by weight.

Example 1 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts Polymer surfactant Polystyrene-polypropylene 3 parts of block polymer A mixture of the above composition was melt-kneaded, cooled, coarsely pulverized using a hammer mill, and then finely pulverized by a fine pulverizer using an air jet method. The obtained finely pulverized product was classified to have an average particle size of 7.5 μm. 0.5 part of silica fine powder was added to and mixed with 100 parts of the present particles to obtain a toner of the present invention.

When the cross section of the obtained toner is observed by TEM, it is a sea-island structure formed by the base polymer and the polypropylene, and the maximum diameter in the major axis direction of the island formed by the polypropylene is 1500 mm, and the island in the distribution of the island is formed. The distance between the toner and the island is 850mm and any 1μm on the toner surface
The area ratio of the island portion within the area of × 1 μm is 33% when measured by an image processing apparatus, and the island portion is microscopic FT-IR.
(Manufactured by JASCO Corporation), it was polypropylene.

Using the obtained toner, an image was formed with a developing device as shown in FIG. 1. As a result, a clear image was obtained without filming on the surface of the developing roller, high image density and no background contamination. Was done.

The image remained unchanged after 100,000 runs. The charge amount at the beginning of the running was -9.8 (μc / g), which was hardly changed.

Comparative Example 1 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts The mixture having the above composition was melt-kneaded. After cooling, the mixture was coarsely pulverized using a hammer mill, and then finely pulverized by a fine pulverizer using an air jet method. The obtained finely pulverized product was classified to have an average particle size of 7.5 μm. 0.5 part of silica fine powder was added to and mixed with 100 parts of the particles to obtain a toner for comparison.

When the cross section of this toner is observed by TEM, it is a sea-island structure formed by the base polymer and the polypropylene, and the maximum diameter in the major axis direction of the island portion formed by the polypropylene is 1600.
0 °, the average distance between islands in the distribution of islands is 1.3 μm, and an arbitrary 1 μm
The area ratio of the island-shaped portion in the area of m × 1 μm was 70% when measured by the image processing apparatus. Using the obtained toner,
When an image was formed in the same manner as in Example 1, the obtained image had a low dark image density, and density unevenness was observed in some places. In addition, filming occurred on the developing roller during running of 10,000 sheets.

Example 2 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 5 parts Polymer surfactant Polystyrene-polypropylene Block Polymer 2 parts The mixture having the above composition was melt-kneaded, cooled, roughly pulverized using a hammer mill, and then finely pulverized by a pulverizer using an air jet method. The obtained finely pulverized product was classified to have an average particle size of 8.4 μm. 0.3 parts of silica fine powder was added to and mixed with 100 parts of the present particles to obtain a toner of the present invention.

TEM observation of the cross section of this toner shows a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the major axis direction of the island-shaped portion formed by polypropylene is 27.
00Å, and the distance between islands in the distribution of island-like portions is 19
20 ° and any 1 μm × 1 on the toner surface
The area ratio of the island portion in the area of μm was 45% when measured by an image processing apparatus, and the island portion was measured by micro FT-IR (manufactured by JASCO Corporation), and it was found to be polypropylene.

When an image was formed using the obtained toner in the same manner as in Example 1, no filming was found on the surface of the developing roller, and a high-density image and a clear image without background contamination were obtained. The image did not change after 100,000 runs. The expected charge of the running is -10.5 (μc / g),
The charge amount after running was -10.0 (μc / g), which was almost the same as expected.

Comparative Example 2 Binder resin Styrene-acrylic acid polymer 70 parts Ester polymer 25 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 5 parts The mixture having the above composition was melt-kneaded. After cooling, the mixture was coarsely pulverized using a hammer mill, and then finely pulverized by a fine pulverizer using an air jet method. The obtained finely pulverized product was classified to have an average particle size of 8.2 μm. 0.3 part of silica fine powder was added to and mixed with 100 parts of the present particles to obtain a comparative toner.

TEM observation of the cross section of the toner shows a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the major axis direction of the island-shaped portion formed by polypropylene is 14
500Å, and the distance between islands in the distribution of islands is
1.5 μm and any 1 μm on the toner surface
The area ratio of the island-shaped portion in the area of × 1 μm was 2% when measured by the image processing apparatus. When an image was formed using this toner in the same manner as in Example 1, the obtained image had a low image density, and density unevenness was observed in some places. Also one
In the running of 10,000 sheets, filming occurred on the developing roller.

Example 3 Binder resin Styrene-methacrylic acid polymer 60 parts Styrene-2 ethylhexyl polymer 20 parts Ester polymer 25 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts Polymeric Surfactant Styrene-2-ethylhexyl block polymer 4 parts The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized using a hammer mill, and then finely pulverized by an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 8.8 μm. 0.4 part of silica fine powder was added to and mixed with 100 parts of the present particles to obtain a toner of the present invention.

When the cross section of this toner is observed by TEM, it has a sea-island structure formed by the base polymer and the polypropylene, and the maximum diameter in the major axis direction of the island portion formed by the polypropylene is 70%.
0Å, and the distance between islands in the distribution of islands is 272.
0 ° and any 1 μm × 1 on the toner surface
The area ratio of the island-shaped portion in the area of μm was 30% when measured by an image processing apparatus, and when the island-shaped portion was measured by microscopic FT-IR (manufactured by JASCO Corporation), it was found to be polypropylene.

An image was formed using this toner in the same manner as in Example 1. As a result, a clear image with no filming on the surface of the developing roller, a high-density image and no background stain was obtained. The image did not change after 100,000 runs. The charge amount at the beginning of the running was -13.5 (μc / g), which was almost the same as the initial expectation.

Comparative Example 3 Binder Resin Styrene-acrylic acid polymer 50 parts Styrene-2 ethylhexyl polymer 20 parts Ester polymer 25 parts Release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts The mixture having the above composition was melt-kneaded, cooled, coarsely pulverized by using a hammer mill, and then finely pulverized by an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 8.5 μm. 0.4 part of silica fine powder was added to and mixed with 100 parts of the present particles to obtain a comparative toner.

TEM observation of the cross section of the toner shows a sea-island structure formed by the base polymer and the polypropylene, and the maximum diameter in the major axis direction of the island-shaped portion formed by the polypropylene is 13
300Å, and the distance between islands in the distribution of islands is
1.6 μm and any 1 μm on the toner surface
The area ratio of the island-shaped portions in the area of × 1 μm was 66% when measured by the image processing apparatus. When an image was formed using this toner in the same manner as in Example 1, the obtained image had a low image density, and density unevenness was observed in some places. Also one
In the running of 10,000 sheets, filming occurred on the developing roller.

〔The invention's effect〕

Since the electrostatic image developing toner of the present invention has a specific sea-island structure, when an image is formed using the toner, pulverization of the toner on the photoconductive photosensitive pair or the developing sleeve is suppressed, As a result, filming in which toner adheres and melts does not occur on the photoconductive photoconductor or the developing sleeve. Further, a state in which the adhered toner is thinned and a film is not formed does not occur. Further, the frictional charging property between the toner and the developing sleeve is stably maintained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a developing device using the non-magnetic one-component toner of the present invention useful for carrying out the method of the present invention. 1 .... Electrostatic latent image carrier, 2 .... Toner conveying member, 3 ....
Toner layer thickness regulating member, 4... Toner supply member, 5... Stirring blade, 6... Toner, 7.

Claims (1)

(57) [Claims] 1. A toner comprising at least a binder resin and a colorant, wherein a higher order structure in a polymer blend system when a cross section of the toner is observed with a transmission electron microscope is a sea-island structure formed by a base polymer and polypropylene, The maximum diameter in the major axis direction of the islands formed by the polypropylene is 200 to 3000 mm, the average distance between the islands in the distribution of the islands is 1 μm or less, and an arbitrary 1 μm × 1 μm area on the toner surface. A toner for developing an electrostatic charge image, wherein an area ratio of an island portion is 5 to 60% as measured by an image processing apparatus.