JPH03296067A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To prevent the pulverization of a toner on a photoconductive photosensitive body and a developing sleeve by providing a specific sea-and-island structure. CONSTITUTION:The higher structure of the polymer blend system when the toner section is observed with a transmission type electron microscope is made into the sea-and-island structure formed of a base polymer and polypropylene (PP). The max. diameter in the major axis direction of the island part formed of the PP is specified to 200 to 3,000Angstrom . The average intervals of the islands and islands in the distribution of the island parts is confined to <=1mum and the area ratio of the island parts within an arbitrary area of 1mumX1mum on the toner surface is confined to 5 to 60% when measured by an image processor. The pulverization of the toner particles on the photosensitive body 1 and the developing sleeve 2 is suppressed in this way.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a toner for developing an electrostatic latent image formed in electrophotography, electrostatic recording, electrostatic printing, etc. relates to binder resin.

[Conventional technology]

Generally, in electrophotography, electrostatic recording, etc., in order to develop an electrostatic latent image formed on a latent image carrier made of a photoconductive photoreceptor or a dielectric material, a toner supply roller such as a developing sleeve is used. Using a toner that has been made into a thin layer with a blade, etc., and appropriately charged and pulverized, the toner image is transferred to a transfer material such as paper using a developing machine, if necessary, and then fixed by heating pressure, solvent vapor, etc. and a copy is obtained.

The developing methods applied to these electrophotographic methods can be roughly divided into dry developing methods and wet developing methods.

The former is further divided into a method using a two-component developer and a method using a one-component developer. The two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, etc., depending on the type of carrier that transports the toner.

In addition, the -component development methods include the powder cloud method, in which toner particles are sprayed, and the contact development method, in which toner particles are brought into direct contact with the electrostatic latent image surface (contact development or toner development method). ), a jumping development method in which toner particles are not brought into direct contact with the electrostatic latent image surface, but are charged and flown toward the latent image surface by the electric field of the electrostatic latent image; There is the MagneDry method, which develops by contacting the electrolatent image surface.

Toners used in these development methods contain low molecular weight polyethylene or polypropylene as a release agent in order to improve offset properties in the fixed portion.

This is because the low molecular weight polyethylene or polypropylene in this case has poor compatibility with the polystyrene used as the binder resin.

Phase separation occurs during crosstalk. The interface due to phase separation is easily destroyed by the application of mechanical force, and a phenomenon is observed in which the toner is pulverized. For example, toner is pulverized at the contact surface between the photoconductive photoreceptor and the paper, at the contact surface between the developing sleeve (developing roller) and the blade, or even at the contact surface between the developing sleeve and the photoconductive photoreceptor. A phenomenon occurs.

For example, in the case of a contact development method, the finely divided toner adheres to the developing sleeve and causes a fusion phenomenon over time, forming a film on the developing sleeve. , non-uniformity occurs in the thickness of the thinned toner layer, which causes non-uniform distribution of the amount of charge during development of the electrostatic latent image, which causes non-uniformity in the amount of toner adhering per unit area on the developing sleeve. As a result, shading also occurs on the copy, which is a serious problem in terms of images. The pulverization of the toner caused by the fragility of the toner particles means that they are easily crushed by mechanical force, which is preferable from the viewpoint of toner productivity.

Therefore, in order to avoid this kind of filming phenomenon,
It is possible to use a polymer with a high molecular weight, but considering the thermal fixation of images that is usually performed in the final process of copying or printing, the fixing temperature increases and more heat is required for fixing, so it is energy-saving. This is undesirable from the viewpoint of downsizing or miniaturization of hardware equipment. Furthermore, in order to eliminate this phenomenon, it has been proposed to add a small amount of plasticizer to the toner, but there are problems such as impairing the free flow properties of the toner and contaminating the carrier etc. Not successful. Furthermore, if the toner is too hard, it may become impossible to mechanically crush it, or it may not be able to be sufficiently dispersed due to crosstalk.

For the reasons mentioned above, relatively low molecular weight polystyrene or styrene-butyl methacrylate copolymer, which can have appropriate hardness, has been used as a binder resin for toners. However, for devices such as laser printers that use electrophotography and require maintenance-free operation, relatively low molecular weight polystyrene or styrene-butyl methacrylate copolymers do not have sufficient hardness; It has become clear that materials with high quality are required. Also, with this type of binder resin.

In the heat fixing process using a heat roll, which is commonly used at present, its characteristics are insufficient. Although the toner binder resin melts due to heat and the adhesion to paper etc. is good, there is an offset phenomenon to the heat roll. Be looked at.

Further, fluidization promoters are often used to suppress filming on the developing roller or photoreceptor and spending on the carrier. For example, JP-A-47-36405 and JP-A-47-36830 disclose the use of metal soap;
In the publication, the use of fluorine-based compounds is disclosed in
No. 34 proposes the use of a nonionic surfactant, and JP-A-56-62256 proposes the use of silica whose surface has been rendered hydrophobic.

Furthermore, Japanese Patent Application Laid-Open No. 56-66856 discloses that particles harder than the toner are embedded in the surface of the toner.
In Japanese Patent Application Laid-open No. 134651, 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, which is compatible with the binder resin and has a mold release effect. JP-A-56-197048 discloses that silicone oil is contained in a binder resin.

Japanese Patent Application Laid-Open No. 59-220748 discloses that wax fine particles are externally added to toner, as disclosed in Japanese Patent Application Laid-open No. 60-138565.
The publication discloses that carbon black is externally added to reduce the resistance of toner, as disclosed in JP-A-60-186851 and JP-A-6
0-186852, JP 60-186853, JP 60-186854, JP 60-186855
No., JP-A-60-186857, JP-A-60-186
No. 858, JP-A-60-186860, JP-A-60-
186861, JP 60-186862, JP 60-186863, JP 60-186864,
JP-A-60-186865, JP-A-60-18686
No. 6 discloses that polymer fine particles are externally added, and JP-A No. 61-99164 discloses that an abrasive (SiC,
It has been proposed to add 5iN) externally.

[Problem to be solved by the invention]

However, just by using additives as mentioned above,
The effect of suppressing filming on the developing roller and photoreceptor and spent on the carrier is still insufficient, and it is possible to prevent filming and spent by improving the higher-order structure of the toner formed by the polymer, which is the main component of the toner. The best way is to avoid this.

Therefore, an object of the present invention is to suppress toner particles from becoming fine powder on a photoreceptor or a developing sleeve, and to prevent the toner particles from becoming fine powder on the developing sleeve and the photoreceptor due to frictional heat between the developing sleeve and the photoreceptor or between the developing sleeve and the blade. Toner for developing electrostatic charge images that suppresses filming on bodies, spent on carriers, and sticking to blades, and provides permanently good copied images with the above-mentioned suppressing effects, and image formation by a one-component development method using the same. The purpose is to provide a method.

[Means to solve the problem]

As a result of intensive research, the present inventors found that a toner having a specific seabird structure is suitable for the above purpose, and completed the present invention.

That is, according to the present invention, in a toner consisting of at least a binder resin and a colorant, when a cross section of the toner is observed under a transmission electron microscope, the higher-order structure in the polymer blend system is a seabird structure formed by the base polymer and polypropylene. The maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene is 200-3000 mm, the average interval between islands in the distribution of the island-shaped portion is 1 or less, and the toner surface has an arbitrary diameter. The island-shaped part area ratio within the area of 14XIIjs is 5 when measured with an image processing device.
60% is provided.

The toner is composed of a plurality of polymers, and the polymers are mixed at the micron level by melt mixing. The above state is made clear by dyeing a cross section of the toner and observing it with a transmission electron microscope (TEM). In order to prevent offset during fixing, low molecular weight polypropylene, low molecular weight polyethylene, wax, etc. are usually mixed in the oilless donor to impart release properties. These mold release agents such as low molecular weight polypropylene are
By receiving and absorbing thermal energy from the fixing roller during fixing, the toner prevents the toner from seeping out and offsetting to the fixing roller.

On the other hand, toner adheres to the developing roller or photoreceptor over time, resulting in a phenomenon called filming. This filming substance is a low molecular weight polypropylene that has a releasing effect and is present in the toner as a result of surface analysis.
Alternatively, it was found that low molecular weight polypropylene was the main component. TEM observation of a cross section of the toner where this filming easily occurs shows that the higher-order structure in the polymer blend system is a seabird structure formed by the base polymer and polypropylene, and the length of the island-like part formed by polypropylene is The maximum diameter in the axial direction is 1.7 tones, the distance between the islands in the distribution of the island-like portions is 1.2 tones or more, and the toner surface.

It became clear that the area ratio of the island-shaped portion within the area of I×1− of a certain portion was 70% or more when measured with an image processing device.

In other words, the low molecular weight release agent present on the surface of the toner has an island in the higher-order structure of the polymer in the form of a seabird structure, and this island becomes larger. : It is thought that filming is more likely to occur. In other words, as the island-shaped low molecular weight mold release agent becomes larger, the low molecular weight mold release agent easily oozes out from the toner surface due to the frictional heat generated by the toner supply member etc. when the toner adheres to the developing roller. Become. As a result, the low molecular weight release agent becomes a thin layer on the developing roller, forming a film. The state of existence of the low molecular weight release agent component in this polymer is thought to be controlled by the viscosity change due to the change in molecular weight during melt mixing.

In addition, the maximum diameter of the island-like part in the TEM observation of toner is 1
．． When the pitch is very large, such as 7 tones or more, the toner tends to be easily pulverized on the developing roller. This phenomenon occurs because the polymer alloying in the toner is not sufficient, resulting in a gap between the main polymer and the low molecular weight release agent component.
It is presumed that this occurs due to interfacial peeling.

Therefore, the maximum diameter in the long axis direction of the island-like part, the distribution of the island-like part, and the area ratio of the island-like part within a given area in the TEH observation of the toner cross section are measures that indicate the filming property of the toner. By the value being within the above range,
The toner is less likely to be pulverized on the developing roller, and filming on the developing roller and fogging during development are reduced.

If the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene in the toner cross section is less than 200 mm, the low molecular weight release agent component in the polymer alloy will almost completely form a regular phase like a block polymer. Since the toner becomes a polymer alloy with a structured structure, polypropylene is no longer preferentially eluted onto the toner surface during fixing, and as a result, an offset phenomenon occurs during fixing.

Furthermore, if the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene in the cross section of the toner exceeds 3,000, the interaction force at the interface between the main polymer and polypropylene in a phase-separated state decreases, and as a result, the developing roller Due to friction with the toner supply member, toner layer regulating member, or photoreceptor, the toner becomes finely powdered, which tends to cause filming on the developing roller and fogging during development.

Furthermore, if the interval between islands in the distribution of island-like portions exceeds 1-, the distribution of polypropylene becomes localized, so that polypropylene tends to be easily eluted.

Furthermore, if the island-like area ratio within an arbitrary 1-voice x 1- area on the toner surface is less than 5% when measured with an image processing device, an undesirable offset phenomenon will occur during fixing, and If it exceeds 60%, it will melt on the developing roller or photoreceptor and cause a filming phenomenon, making it impossible to achieve the intended purpose of the present invention.

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

The binder resin used in the toner of the present invention includes:
The binder resin is not limited to the above-mentioned polystyrene and styrene-butyl methacrylate copolymer, but binder resins that have been conventionally used as binder resins for toners can be used. Specifically, the monomer of the binder resin includes styrene, 0-methylstyrene, -1-methylstyrene, P-methylstyrene,
P-ethylstyrene, 2,4-dimethylstyrene, p-
n-butylstyrene.

p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, P-n-decylstyrene, p-n-dodecylstyrene, P-methoxystyrene, p- Styrenes such as phenylstyrene, P-chlorostyrene, and 3,4-dichlorostyrene; Ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and imbutylene; Vinyl chloride, vinylidene chloride, vinyl bromine, vinyl fluoride vinyl halides such as vinyl acetate, vinyl propionate, etc.; methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, 〇-butyl methacrylate, etc. α-methylene aliphatic monocarboxylic acid esters: vinyl ethers such as vinyl methyl ether; vinyl ketones such as vinyl methyl ketone; N-vinylpyrol, N-
Examples include N-vinyl compounds such as vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone. These monomers can be used alone or in combination of two or more types.

In addition, as monomers for forming polycondensation type resin,
Ethylene glycol, triethylene glycol, 1,2
- Polyhydric alcohols such as propylene glycol, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A; polyhydric amines such as ethylenediamine, tetramethylenediamine, piperazine; maleic acid, fumar Examples include acids, mesaconic acid, citraconic acid, adipic acid, malonic acid, and their acid anhydrides or esters with lower alcohols.

Note that the toner of the present invention contains a colorant, and can also contain a charge control agent and the like if desired.

As the colorant used in the toner of the present invention, all pigments and dyes conventionally used as colorants for toners can be used. Specifically, carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, calco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, and Hansa yellow G.
, rhodamine 6C lake, chrome yellow, quinacridone, benzidine yellow, malachite green, malachite green hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, trisazo dyes and pigments, and mixtures thereof. can be mentioned.

In addition, charge control agents that impart positive polarity to the toner include nigrosine dyes, quaternary ammonium salts,
There are basic dyes, amino acid-containing polymers, and chromium-containing monoazo dyes, which provide negative polarity.
Examples include chlorine-containing organic dyes and metal salts of salicylic acid derivatives.

Furthermore, the toner of the present invention may contain a fluidizing agent. Examples of the fluidizing agent include inorganic oxides such as SiO□ and TiO2 whose surfaces have been subjected to hydrophobic treatment, inorganic fine particles such as SiC, and metal soaps such as zinc stearate.

The toner of the present invention is particularly useful for image formation using a one-component development method in electrophotography, and the image forming method of the present invention will be described next.

The image forming method of the present invention is an image forming method using a one-component development method in electrophotography in which a thin layer of toner is supplied to a latent image carrier to develop a latent image. It is characterized by using Note that toner thinning is usually achieved by including a toner conveying member, a toner layer thickness regulating member, and a toner supplying member, and in which the toner supplying member and toner conveying member and the toner layer thickness regulating member and toner conveying member are in contact with each other. It is carried out using the same equipment.

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

FIG. 1 is a schematic cross-sectional view of an example of a developing device using a non-magnetic component toner useful in carrying out the method of the present invention. In FIG. 1, the 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 transferred to the toner supply member (sponge roller) 4. 4. Then, as the toner supply member 4 rotates in the direction of the arrow, the toner taken into the toner supply member 4 is transported to the toner transport member (developing roller) 2, where it is rubbed and electrostatically or physically attracted. , the toner conveying member 2 rotates strongly in the direction of the arrow, and a uniform thin layer of toner is formed by the steel toner layer thickness regulating member (elastic blade) 3 and is frictionally charged. Thereafter, the toner is transported to the surface of the electrostatic latent image carrier 1 that is in contact with or in close proximity to the toner transport member 2, and the latent image is developed. The electrostatic latent image is created by charging the organic photoreceptor with a negative DC charge of 800 cm and then exposing it to light to form a latent image, which is then developed.

Note that the developing device suitable for the toner of the present invention is not limited to the one described above.

In such an image forming method using a one-component development method in electrophotography, if finely powdered toner adheres to the developing sleeve and forms a film, it will greatly affect the ability to form a uniform thin layer of toner. The toner is suppressed from being pulverized on the photoconductive photoreceptor or developing sleeve, and its formation is suppressed from forming on the imaging sleeve or photoconductive photoreceptor, so that the toner is uniformly formed in a single layer on the developing sleeve. 1. By the method of the present invention, for a long period of time,
High quality images can be obtained.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited thereto. Note that parts represent parts by weight.

Example 1 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Mold release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts A mixture of the above composition was melt-kneaded. ,
After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The resulting finely pulverized product was classified to have an average particle size of 7.5 mm. This particle 1
A toner of the present invention was obtained by adding and mixing 0.5 parts of silica fine powder to 00 parts.

TEM observation of the cross section of the obtained toner reveals that it has a seabird structure formed by the base polymer and polypropylene, and the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene is 1,500 mm. The spacing between islands is 850, and the toner surface has an arbitrary 1. The area ratio of the island-like part within the area of csXIR was 33% when measured with an image processing device, and when the island-like part was measured with a microscope FT-IR (manufactured by JASCO Corporation), it was found to be polypropylene.

When the obtained toner was used to produce an image using a developing device as shown in Figure 1, a clear image was obtained with no filming on the developing roller surface, high image density, and no background stains. It was done.

Moreover, this image remained unchanged even after running 100,000 images. The charge amount at the initial stage of running was -9.8 (μc/g), which was almost unchanged.

Comparative Example 1 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Mold release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts A mixture of the above composition was melt-kneaded. ,
After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 7.5-. This particle 1
A comparative toner was obtained by adding and mixing 0.5 part of silica fine powder to 00 parts.

TEM observation of the cross section of this toner shows that it has a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene is 16
000 people, the average spacing between islands in the distribution of island-like parts is 1.3-, and the island-like part area ratio within an arbitrary 14 x 14 area on the toner surface is 70 when measured with an image processing device. %Met. When an image was produced using the obtained toner in the same manner as in Example 1, the resulting image had a low image density, and density unevenness was visible in some places. Further, during the running of 10,000 sheets, filming occurred on the developing roller.

Example 2 Binder resin Styrene-acrylic acid polymer 60 parts Ester polymer 35 parts Mold release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 5 parts A mixture of the above composition was melt-kneaded. ,
After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The resulting finely pulverized product was classified to have an average particle size of 8.4 tones. This particle 1
A toner of the present invention was obtained by adding and mixing 0.3 parts of fine silica powder to 00 parts.

TEM11 cross section of this toner! As we can see, it is a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the long axis direction of the island-like part formed by polypropylene is 2,700 people, and the distance between islands in the distribution of the island-like parts is 1,920 people. , and the area ratio of the island-shaped portion within an arbitrary area of 1 pg The material was measured to be polypropylene.

When the obtained toner was used to produce an image in the same manner as in Example 1, a clear image with no filming on the surface of the developing roller, a high density image, and no background stains was obtained. The image remained unchanged even after running 100,000 images. The amount of charge at the beginning of running is -10.5 (μc/g)
So, the amount of charge after running is -10.0 (μc/g
), which remained almost unchanged from the initial period.

Comparative Example 2 Binder resin 70 parts 25 parts 5 parts 10 parts 5 parts Styrene-acrylic acid polymer Ester polymer Mold release agent Polypropylene colorant Carbon black Charge control agent Salicylic acid derivative Zinc salt A mixture of the above composition was melt-kneaded. After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 8.2 parts m. A comparative toner was obtained by adding and mixing 0.3 parts of silica fine powder to 100 parts of the present particles.

TEM observation of the cross section of this toner shows that it has a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene is 1.
4,500 people, the distance between islands in the distribution of island-shaped parts is 1.5-, and the toner surface has an arbitrary 1
The island-like portion area ratio within the area of ts X l- was 2% when measured with an image processing device. When an image was produced using this toner in the same manner as in Example 1, the resulting image had a low image density, and density unevenness was visible in some places. Further, during the running of 10,000 sheets, filming occurred on the developing roller.

Example 3 Binder resin Styrene-methacrylic acid polymer 60 parts Styrene-2-functional tylhexyl polymer 20 parts Ester polymer 25 parts Mold release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 Part: Melt and knead the mixture having the above composition,
After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 8.8. Closed. This particle 1
A toner of the present invention was obtained by adding and mixing 0.4 parts of fine silica powder to 00 parts.

A TEM observation of the cross section of this toner shows that it has a sea-island structure formed by the pace polymer and polypropylene, and the maximum diameter in the long axis direction of the island-shaped portion formed by the polypropylene is 7.
00 people, the interval between islands in the distribution of island-like parts is 2720 people, and any 14 people on the toner surface.
The area ratio of the island-like part within the area of X14 is 30% when measured with an image processing device, and the island-like part is
When measured with R (manufactured by JASCO Corporation), it was found to be polypropylene.

When an image was produced using this toner in the same manner as in Example 1, a clear image with no filming on the surface of the developing roller, a high density image, and no background stains was obtained. The image remained unchanged even after running 100,000 images. The amount of charge at the initial stage of running was -13.5 (μc/g), which was almost unchanged from the initial stage.

Comparative Example 3 Binder resin Styrene-acrylic acid polymer 50 parts Ester polymer 25 parts Mold release agent Polypropylene 5 parts Colorant carbon black 10 parts Charge control agent Salicylic acid derivative zinc salt 6 parts A mixture of the above composition was melted and mixed. ,
After cooling, it was coarsely pulverized using a hammer mill, and then finely pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 8.51R. A comparative toner was obtained by adding and mixing 0.4 parts of silica fine powder to 100 parts of the present particles.

TEM observation of the cross section of this toner shows that it has a sea-island structure formed by the base polymer and polypropylene, and the maximum diameter in the long axis direction of the island-shaped portion formed by polypropylene is 1.
3,300 people, the interval between islands in the distribution of island-like parts is 1.6Ia, and the island-like part area ratio within an arbitrary 14x1pa area on the toner surface is 66% when measured with an image processing device. Met. When an image was produced using this toner in the same manner as in Example 1, the resulting image had a low image density and density unevenness was visible in some places9.
Further, during the running of 10,000 sheets, filming occurred on the developing roller.

〔Effect of the invention〕

Since the toner for developing an electrostatic image of the present invention has a specific seabird structure, when an image is formed using the toner,
The pulverization of the toner on the photoconductive photoreceptor or the developing sleeve is suppressed, and as a result, filming in which the toner adheres and melts does not occur on the photoconductive photoreceptor or the developing sleeve.

Further, the adhered toner does not become a thin layer and a film is formed, and furthermore, the triboelectricity between the toner and the developing sleeve etc. is maintained stably.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] (1) In a toner consisting of at least a binder resin and a colorant, when a cross section of the toner is observed under a transmission electron microscope, the higher-order structure of the polymer blend system is a sea-island structure formed by the base polymer and polypropylene, and the polypropylene is The maximum diameter in the long axis direction of the island-like portions to be formed is 200 to 3000 Å, the average interval between islands in the distribution of the island-like portions is 1 μm or less, and within an arbitrary area of 1 μm × 1 μm on the toner surface. A toner for developing an electrostatic image, characterized in that the island-like portion area ratio is 5 to 60% when measured with an image processing device.