JPH06313981A - Developer for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To provide a developer for developing electrostatic charge image which has excellent developing characteristics, especially superior, inhibitory effect on the selective development and is appropriately, used for the image forming method using an organic photosensitive body. CONSTITUTION:The developer for developing electrostatic charge image features that it comprises: (1) an insulating toner which has 4 to 12mum weight average particle size (t-D4) and 1 to 10mum length average particle size (t-D1), wherein the ratio of (t-D1)/(t-D1) is 1.01 to 2; (2) a fluidizing agent which is charged in the same polarity as that of the insulating toner and has a >=30m<2>/g specific surface area determined by the BET method based on N2 adsorption; (3) an inorganic fine powder which is charged in the opposite polarity to that of the insulating toner and has 0.6 to 5mum weight average particle size (m-D4) and 0.5 to 4mum length average particle size (m-D1), wherein the ratio of (m D4)/(m-D1) is 1.0 to 2.4 and also (m-D4)/(m-D1) >=(t-D4)/(t-D1); and (4) an organic fine powder which is charged in the opposite polarity to that of the insulating toner and has <=0.8mum length average particle size (P-D1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for developing an electrostatic charge image used in image forming methods such as electrophotography, electrostatic recording and electrostatic printing.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and JP-B-42-23910 are known.
A number of methods are known as described in Japanese Patent Publication No. 43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then the latent image is developed with a toner, and a toner image is formed on a transfer material such as paper if necessary. After transfer, the toner is fixed by heating, pressure, heating and pressurizing or solvent vapor to obtain a toner image.

Various methods and devices have been developed for the final step of fixing the toner image on a sheet such as paper, but the most general method at present is a pressure heating method using a heat roller.

In the pressure contact heating method using a heating roller, the surface of the heat roller having a releasability for the toner and the toner image surface of the sheet to be fixed are brought into contact with each other under pressure to pass the sheet to be fixed, thereby fixing the toner image. Is to do. In this method, the surface of the heat roller and the toner image on the sheet to be fixed come into contact with each other under pressure, so that the thermal efficiency at the time of fusing the toner image on the sheet to be fixed is extremely good, and quick fixing is required. And is very effective in high speed electrophotographic copying machines.

In such a fixing method, the use of a binder resin containing an acid component in order to improve the fixing property is proposed in JP-A-55-134861. However, a toner using such a binder resin is liable to suffer from insufficient charging under high humidity and excessive charging under low humidity, and is easily affected by environmental fluctuations. Further, fogging is likely to occur and the image density may be low.

On the other hand, the acid anhydride has a function of improving the charging property, and examples of applying a resin containing the acid anhydride are disclosed in JP-A-59-139053 and JP-A-62-280758.
It is proposed in Japanese Patent Publication No. In these methods, a polymer having a high density of acid anhydride units is diluted with a binder resin. In these methods, it is necessary to uniformly disperse the acid anhydride-containing resin in the binder resin, and if not well dispersed, the toner particles become non-uniformly charged, fogging easily occurs, and the developability is adversely affected. .

Therefore, the dispersion of the acid anhydride unit in the polymer chain of the binder resin by copolymerization and dilution can solve the problem of dispersion and provide toner particles having uniform chargeability. . Japanese Patent Laid-Open No. 61-123856.
These toners have been proposed in JP-A 61-123857 and the like. These toners have good fixability, offset resistance, and developability.

However, when such a toner is applied to a high-speed copying machine under low humidity, it may be overcharged, resulting in fog and a decrease in density.

Further, in recent years, there has been a demand for multifunctional copying machines and higher image quality of copied images due to digitization of copying machines and reduction in toner particle size.

However, in the multi-functionalization of the copying machine, for example, a part of the image is erased by exposure or the like,
Next, in the function of performing multi-color multi-color copying in which another image is inserted in that portion, or in the function of cutting out the periphery of the copy paper, a fog occurs in a portion to be whitened on the image.

That is, when an image is erased by applying a potential opposite to the latent image potential with respect to the development reference potential with strong light such as an LED or a fuse lamp, there is a problem that the fog tends to occur at that portion. .

Further, although the resolution and the sharpness of the image can be improved by the digitization and the smaller particle size of the toner, various problems occur.

First, there is the above-mentioned problem of fog. By reducing the toner particle size, the surface area of the toner is increased, so that the width of the charge amount distribution is increased and fogging is likely to occur. In addition, the increase in the toner surface area makes the charging characteristics of the toner more susceptible to the environment.

Further, when the toner particle size is reduced, it is obvious that the dispersion state of the polar substance and the colorant has a great influence on the chargeability of the toner.

Further, in recent digital copying machines,
In a photographic image containing characters, the characters of the copied image are clear, and the photographic image is required to have density gradation that is faithful to the original. Generally, in copying a photographic image containing characters, if the line density is increased to make the characters clear, not only the density gradation of the photographic image is impaired, but also the halftone portion becomes a very rough image. On the other hand, if an attempt is made to improve the density gradation of the photographic image, the density of the character line will decrease and the sharpness will deteriorate.

In recent years, the image density is read and the density gradation is improved to some extent by digital conversion. However, the present situation is still not enough.

This is largely due to the developing characteristics of the developer. That is, the development potential (difference between the photoconductor potential and the developer carrying potential) and the image density do not have a linear relationship.
As shown by (solid line), a downwardly convex curve is drawn where the development potential is low, and an upwardly convex curve is drawn where the development potential is high. Therefore, in the halftone region, a slight change in the development potential causes a very large change in the image density. This makes it difficult to obtain a sufficiently satisfactory density gradation.

Usually, in order to copy a line image and maintain its sharpness, the maximum image density in the solid image portion which is not easily affected by the edge effect is 1.30 because it is affected by the edge effect.
Something is enough.

However, in a photographic image, the maximum density of the photograph itself is largely due to its surface glossiness, which is 1.9.
It is very high at 0-2.00. Therefore, in copying a photographic image, even if the glossiness of the surface is suppressed, since the image area is large, the density is not increased by the edge effect. Therefore, the maximum image density in the solid image part is 1.4 to About 1.5 is necessary.

Therefore, the developing potential and the image density have a linear (linear) relationship, and the maximum image density is 1.4 to
Setting 1.5 is very important for copying a photo image with text.

For this purpose, it is important to control the charge amount of the toner as uniformly as possible.

As a method for preventing the increase of the charge amount of the toner and stabilizing the charge amount by using a conductive powder, Japanese Patent Laid-Open No. 58-58 is known.
-66951, JP-A-59-168458-16
Japanese Patent Application Laid-Open No. 8460 and Japanese Patent Application Laid-Open No. 59-170847 disclose methods using conductive zinc oxide and tin oxide. According to these methods, the maximum image density is 1.3.
In a system using a large amount of conductive powder, the value is 1.4 or more, but the density gradation is poor. It is well known that the charge amount distribution also exists in the toner charge amount, and the distribution width increases as the toner charge amount increases. That is, these methods are intended to reduce the charge amount and sharpen the charge amount distribution by attaching the conductive powder to the toner having a high charge amount. However, even with these methods, a sufficiently satisfactory image cannot be obtained in copying a photographic image with text.

Further, a non-magnetic toner having a volume average particle diameter of 5 to 20 μm is mixed with a fine powder having a volume average particle diameter of 1/20 to 1/2 to stabilize the toner replenishment property to form a thin layer. Japanese Patent Application Laid-Open No. 61-183664 discloses a method of forming a uniform toner layer by using the above method to obtain a sufficient triboelectric charge amount.
In this method, in the color toner, it is possible to stabilize the toner replenishment and form a thin layer on the developer carrying member to increase the charge amount, but in the magnetic toner, as described above,
When the charge amount distribution is sharpened and further copied, the maximum density of 1.4 to 1.5 and sufficient density gradation cannot be obtained.

Further, Japanese Laid-Open Patent Publication No. 60-32060 discloses a method of using two kinds of inorganic powders to remove paper powder, ozone adduct, etc. which are produced or adhered to the surface of the photoconductor. .

Further, in JP-A-2-110475, two kinds of inorganic fine powders are used for a toner using a metal-crosslinked styrene-acrylic resin, and paper powder or ozone which is generated or adhered to the surface of a photoreceptor is used. It discloses a method of removing additions and the like, fixing property of toner, toner scattering under high temperature and high humidity, image deletion, and image density reduction.

Although it is possible to remove the adhering substance on the photoreceptor by these methods, the above-mentioned various problems have not been solved yet.

Further, Japanese Patent Application Laid-Open No. 1-112255 discloses a method of using organic fine particles and two or more kinds of inorganic fine particles. This method is characterized by having two or more kinds of inorganic fine particles and organic fine particles having an average primary particle diameter of 3 μm or less and larger than the average primary particle diameter of the inorganic fine particles. However, even this method has not yet solved all the above-mentioned problems.

As described above, at present, there is no developer capable of solving all of the above various problems.

[0029]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic charge image used in an image forming method using an organic photoconductor, which solves the above problems.

An object of the present invention is to provide a developer for developing an electrostatic charge image, which can obtain a high-density copy image without impairing the fixability, without fog.

An object of the present invention is to provide a developer for developing an electrostatic image which gives good images even under low humidity and high humidity without being affected by environmental changes.

An object of the present invention is to provide a developer for developing an electrostatic charge image which gives a stable and good image even in a high speed machine and has a wide range of applicable models.

An object of the present invention is to provide a developer for developing an electrostatic image which is excellent in durability, has a high image density even after continuous use for a long time, has no fog on a white background, and provides a copy image. is there.

The object of the present invention is excellent in resolving power and reproducibility of fine lines, and in the case of a photographic image containing characters, the characters of the copied image are clear and the photographic image has a density gradation faithful to the original. It is to provide a developer for developing a charge image.

The object of the present invention is to achieve uniform coating of the toner on the developer carrying member and uniform and stable charging of the toner on the developer carrying member for a long time at the same time. An object is to provide a developer for electrostatic charge image development that makes flight more efficient.

[0036]

The present invention has a weight average particle diameter (t-D ₄ ) of ₄ to 12 μm and a length average particle diameter (t-D ₁ ) of ₁ to 10 μm. (T-D ₄ )
An insulating toner having a value of / (t−D ₁ ) of 1.01 to 2,

A fluidizing agent having a specific surface area of 30 m ² / g or more according to the BET method, which is charged to the same polarity as the insulating toner and adsorbs N ₂ .

It is charged in the opposite polarity to the insulating toner, has a weight average particle diameter (m-D ₄ ) of 0.6 to 5 μm, and a length average particle diameter (m-D ₁ ) of 0.5 to 4 μm. Yes, (m-D ₄ )
The value of / (m-D ₁ ) is 1.0 to 2.4 and (m-D 1
_{4) / (m-D 1} ) _{is, (t-D 4) /} (t-D 1) the value equal to or greater than even the inorganic fine powder and the and,

A developer for developing an electrostatic charge image, characterized in that it contains an organic fine powder having a polarity opposite to that of the insulating toner and having a length average particle diameter (p-D ₁ ) of 0.8 μm or less. is there.

As described above, it is well known that the charge amount distribution also exists in the toner charge amount. This distribution state is affected by the distribution state of the materials constituting the toner, such as the magnetic substance and the colorant, and the particle size distribution of the toner. When the materials forming the toner are uniformly dispersed, the charge amount distribution is mainly affected by the particle size distribution of the toner. Generally, a toner having a small particle size has a large charge amount, and a toner having a large particle size has a small charge amount. Further, the distribution width of the toner having a larger charge amount is wider and the toner having a smaller charge amount is narrower.

As a method of sharpening the distribution of the charge amount by using a toner having a high charge amount, there is a method of attaching conductive powder to the toner to reduce the charge amount as described above. It has good properties, but its concentration is not sufficient at the maximum concentration. The present inventors considered the reason for this as follows.

In the method of lowering the charge amount by adhering the conductive powder to the toner, the conductive powder itself is slightly charged but does not uniformly adhere to the toner, and electrostatic charge is applied to the toner having a small particle size. It is thought that more will be attached by the physical force.

In charging due to friction between toner particles, the surfaces of the toner particles that are in contact with each other are charged, and therefore, even on the same toner surface, positive and negative electric charges are distributed. Therefore, since the toner having a smaller particle size has a larger surface area, it is considered that the toner tends to adhere regardless of the charging polarity of the conductive powder. Further, since the toner having a smaller particle size has a larger surface area and the charge amount per unit weight is larger, when the toner is charged in the opposite polarity, it appears as a fog on a white background when copying. Therefore, the fog is improved by putting the conductive powder into the toner and adhering it to the reverse polarity toner having a small particle size.

However, the toner having a small particle size, to which the conductive powder having a large effect of reducing the charge amount is attached, is selectively developed because the charge amount is lowered. Therefore, although the density gradation is improved, since the toner having a small particle size is melted and spread by fixing and the area covering the fixing support is smaller than that of the toner having a large particle size, the maximum image density is However, it is slightly inferior to the case of a toner having a large particle size.

Further, since only the toner having a small particle size is selectively developed, the halftone roughness is good at the initial stage, but if copying is continued, the toner particle size in the developing device becomes large and deteriorates.

As a result of earnest studies, the inventors of the present invention, as opposed to decreasing the charge amount of the toner, are charged with the opposite polarity to the toner,
Further, a method has been found to increase the charge amount of a toner having a low charge amount in the charge amount distribution by contacting the toner with an inorganic fine powder having a weight average particle size of 0.6 to 5 μm. That is, it is intended to obtain a uniformly charged toner by contact friction charging the toner and the inorganic fine powder in the developing device, instead of adhering the inorganic fine powder to the toner for development.

With respect to the toner of a certain particle size, the very small inorganic fine powder has a very large image force on the toner itself, so that it may be agitated in the developing device and rotated by the developer carrier. Even if a shearing force is applied, the toner remains attached to the toner, and thus has the effect of reducing the charge amount of the toner as described above. However, the inorganic fine powder having a certain size with respect to the toner having a certain particle diameter adheres to the toner,
Due to the shearing force received in the developing device, the number of times of contact with the toner increases due to the separation, so that the charge amount of the toner increases conversely.

The present inventors have made detailed studies based on this idea and have found out the following.

Width of particle size distribution of inorganic fine powder [(m-D ₄ ).
/ (M-D ₁ )] is the width of the toner particle size distribution [t-D ₄ ).
/ (T−D ₁ )] or a wider one, a uniform charging property can be obtained. This is because, with respect to a toner having a certain particle diameter, an inorganic fine powder having a particle diameter within a certain range has the ability to remarkably increase the charge amount of the toner. Therefore, the width of the particle size distribution of the inorganic fine powder is preferably wider than the width of the particle size distribution of the toner.

Further, it has been understood that it is important that the developer satisfies the following constitutional requirements.

The toner has a weight average diameter of 4 to 12 μm, a length average diameter of 1 to 10 μm, and a distribution width [(t-D ₄ ) / (t-D ₁ )] of 1.01 to 2 To be.

Use of a fluidizing agent charged to the same polarity as the toner and having a specific surface area of 30 m ² / g or more as measured by the BET method.

The toner is charged in the opposite polarity to the toner, its weight average particle diameter is 0.6 to 5 μm, and its length average particle diameter is 0.5 to 5.
4 μm, and its distribution width [(m−D ₄ ) / (m−D
₁ )] is 1.1 to 2.4.

Use of an organic fine powder which has a polarity opposite to that of the toner and has a length average particle diameter (p-D ₁ ) of 0.5 μm or less.

These are due to the following reasons.

When the weight average particle diameter of the toner exceeds 12 μm, the halftone image becomes rough and the color density becomes 4
If it is less than μm, the fog on the white background becomes poor.

When the toner particle size exceeds 12 μm, an inorganic fine powder having a large particle size is required to increase the charge amount of the toner. The inorganic fine powder having a large particle size is not developed and is accumulated in the vicinity of the developer carrying member.
Therefore, since a large amount of inorganic fine powder having a large particle size is present on the developer carrying member and the amount of toner to be developed is small, white lines appear on the image, the image density is lowered, and the halftone image is rugged. Getting worse.

When the toner particle size is less than 4 μm, in order to increase the charge amount of the toner, the relationship between the particle sizes is as follows.
The particle size of the inorganic fine powder may be reduced. However, at such particle size, the surface area of the toner increases,
Unless a large amount of inorganic fine powder is used, the chargeability of the toner cannot be kept uniform. When a large amount of inorganic fine powder with a small particle size is used, the cleaning blade slips through, that is, cleaning failure occurs, and the inorganic fine powder gradually scrapes off the resin layer of the organic photoconductor, so The sensitivity of the body is deteriorated, and the copy image is deteriorated such as a decrease in image density.

Width of toner particle size distribution [(t-D ₄ ) /
If (t−D ₁ )] is larger than 2, as described above, the spread of the charge amount distribution due to the particle size distribution becomes large, so that even if the inorganic fine powder according to the present invention is used, sufficient uniform chargeability can be obtained. I can't.

Further, in the absence of the fluidizing agent, the fluidity of the toner used in the present invention is remarkably lowered, which also causes charging failure. In the absence of the fluidizing agent, the fluidity of the waste developer in the cleaning section is significantly reduced, so that the amount of resin scraped on the surface layer of the photoconductor is increased or the image is deteriorated due to scratches. .

When the inorganic fine powder having a weight average particle size of more than 5 μm is used, the chargeability of the toner is improved to some extent, but because it is large, the inorganic fine powder is not developed and consumed in the white inverted portion, and is not consumed. In addition, the image quality of the copy image is gradually deteriorated because the amount of the inorganic fine powder on the developer carrier increases as it accumulates in the developing device. If the weight average diameter is smaller than 0.6 μm, the chargeability of the toner is lowered as described above, which is not suitable for the purpose of the present invention.
Further, the ratio of _{(m-D 4) / (} m-D 1) is larger than 2.4, the particle size distribution is too wide, that too fine particle size and, most things too coarse particle size To include
Not preferable.

Further, in the toner and the inorganic fine powder according to the present invention, it is preferable that the inorganic fine powder is charged to the opposite polarity to the toner. In the present invention, the inorganic fine powder is not used by adhering to the toner, but the purpose is to increase the charge by frictional charging.
Not only is the charge amount of the toner reduced, but the frictional charging speed is also reduced, and the initial density of the copy is low. When the copying is continued, the density gradually increases, which is a so-called rising phenomenon.

Further, when the inorganic fine powder having a polarity opposite to that of the toner is used, the toner having a small particle size and the inorganic fine powder having a small particle size interact with each other when mixed. That is, those having a large amount of electric charge per unit weight and a large working surface area act on each other due to their opposite polarities. Therefore, the toner having a large particle size and the inorganic fine powder having a large particle size interact with each other. In the same developing device, a combination of a toner having a small particle size and an inorganic fine powder is less affected by frictional electrification by stirring than a combination of large particles. This is because, when the shearing force due to stirring is applied, the small things often slip through without receiving the shearing force. In addition, the amount of electric charge that the inorganic fine powder having a small particle diameter gives to the toner having a small particle diameter is small because the total charging amount of the inorganic fine powder is small. On the contrary, in the case of the combination of the inorganic fine powder having a large particle diameter and the toner having a large particle diameter, the charging amount of the inorganic fine powder is large due to the influence of contact charging due to stirring.
The charge amount of the toner having a large particle size, which was low depending on the particle size, became large, and the difference in toner particle size in the developing ability disappeared, that is, the above-mentioned phenomenon of selective development did not occur.

From the above, the particle size of the toner and the particle size of the inorganic fine powder are important. Considering the charging mechanism by the interaction, the particle size distribution width of the toner and the particle size distribution width of the inorganic fine powder are considered. And the relationship between the toner particle size and the inorganic fine powder particle size become very important.

As a result of detailed examination, it is preferable that the toner and the inorganic fine powder satisfy the relationship of the following expression with respect to the above, because they can be more effectively exhibited.

[0066]

[Formula 1]

[0067]

[Formula 2]

The organic fine powder, which is charged in the opposite polarity to the toner and has a length average particle diameter (p-D ₁ ) of 0.8 μm or less, adheres to the toner and is partially unevenly distributed on the toner surface. It prevents the toner from charging up due to the agent, and plays a role in uniform charging of the toner. The presence of this organic fine powder makes it possible to adjust the height of the ears of the developer on the developer carrying member, alleviate the edge effect, and reduce the density change in the edge portion even in a solid image. be able to. Therefore, the quality of the copied photographic image is excellent. Also, by relaxing the edge effect, for example,
In a roller transfer device used in a printer or the like in recent years, it is possible to prevent a phenomenon in which only a portion having a large amount of toner sticking out is not transferred and appears white. Further, when an organic photoconductor is used, the presence of the organic fine powder can greatly reduce the amount of abrasion of the organic photoconductor due to the toner and the inorganic fine powder, and thus a copy image can be obtained which is stable and long-term. Further, due to the presence of the organic fine powder, toner scattering can be prevented. When the length average particle diameter (p-D ₁ ) of the organic fine powder is larger than 0.8 μm, the organic fine powder exists in a free state without adhering to the toner, impairing the uniform charging property of the toner, and copying. If you continue to, the image quality of the copied image will gradually deteriorate.

The above-mentioned various problems can be solved only when the developer satisfies the above constituent requirements. Furthermore, in the developer of the present invention, it is possible to prevent the phenomenon that only the toner having a small particle diameter described above is selectively developed and consumed, and therefore, even if copying is continued, halftone It has no roughness, is excellent in fine line reproducibility, is sufficiently satisfactory in terms of density gradation and maximum image density, and can maintain development characteristics of the developer well and suppress selective development. can get.

Further, the constitution of the developer preferable for achieving the object in the present invention will be described in detail below.

Examples of the vinyl copolymer monomer include the following.

For example, styrene, o-methylstyrene, m
-Methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
Styrene and its derivatives such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene and pn-dodecylstyrene; ethylene, Ethylenically unsaturated monoolefins such as propylene, butylene, isobutylene; Unsaturated polyenes such as butadiene;
Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl ester acids such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid α-methylene aliphatic mono-monomers such as n-butyl, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate. Carboxylic acid esters;
Methyl acrylate, ethyl acrylate, acrylic acid n-
Butyl, isobutyl acrylate, propyl acrylate,
Acrylic esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N
-N- such as vinylindole and N-vinylpyrrolidone
Vinyl compounds; vinylnaphthalene compounds; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide; esters of the above α, β-unsaturated acids and diesters of dibasic acids.

Further, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenylsuccinic acid, fumaric acid and mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenylsuccinic anhydride Unsaturated dibasic acid anhydrides such as: maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl ester Half ester of unsaturated dibasic acid such as half ester, alkenylsuccinic acid methyl half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester; unsaturated dibasic acid ester such as dimethyl maleic acid, dimethyl fumaric acid; Acid, methacrylic acid, crotonic acid, such as cinnamic acid alpha, beta-unsaturated acid; crotonic acid anhydride, such as alpha of cinnamic acid anhydride, beta-unsaturated acid anhydride, the alpha, beta
-Anhydrides of unsaturated acids and lower fatty acids; alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides thereof and monomers having a carboxyl group such as monoesters thereof.

Among these, a combination of monomers that forms a styrene-based copolymer or a styrene-acrylic-based copolymer is preferable.

Further, it may be a polymer cross-linked with a cross-linking monomer as exemplified below, if necessary.

Examples of aromatic divinyl compounds include divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include:
Ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and the above compounds The acrylates of the above are replaced by methacrylates; examples of the diacrylate compounds linked by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and polyethylene glycol. # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and the acrylates of the above compounds are meta-acryed. Include those obtained by changing the over preparative; e.g. diacrylate compounds linked with a chain containing an aromatic group and an ether bond, polyoxyethylene (2)
-2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate, and acrylates of the above compounds were replaced with methacrylate. Examples thereof include polyester type diacrylate compounds such as trade name MANDA (Nippon Kayaku Co., Ltd.). As the polyfunctional crosslinking agent, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate,
Oligoester acrylates and those obtained by replacing the acrylates of the above compounds with methacrylates; triallyl cyanurate and triallyl trimellitate.

These cross-linking agents are based on other monomer components 10
It is possible to use 0.01 to 5% by weight (more preferably 0.03 to 3% by weight) with respect to 0% by weight.

Among these crosslinkable monomers, those which are preferably used in the resin for toner from the viewpoints of fixability and anti-offset property are aromatic divinyl compounds (particularly divinylbenzene), chains containing an aromatic group and an ether bond. Examples of the diacrylate compounds bound by

In the present invention, a vinyl monomer homopolymer or copolymer, polyester, polyurethane, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic carbonization. Hydrogen resin, aromatic petroleum resin and the like can be used by mixing with the above-mentioned binder resin, if necessary.

When two or more kinds of resins are mixed and used as a binder resin, as a more preferable form, it is preferable to mix resins having different molecular weights in an appropriate ratio.

The glass transition temperature of this binder resin is 45 to 8
0 ° C., preferably 55 to 70 ° C., number average molecular weight M
n 2,500 to 50,000, weight average molecular weight Mw1
It is preferably from 50,000 to 1,000,000.

The method for synthesizing the vinyl binder resin according to the present invention includes bulk polymerization method, solution polymerization method, suspension polymerization method,
A polymerization method such as an emulsion polymerization method can be used. When using a carboxylic acid monomer or an acid anhydride monomer, it is preferable to use a bulk polymerization method or a solution polymerization method in view of the properties of the monomer.

The composition of the polyester resin used in the present invention is as follows.

The polyester resin used in the present invention is
45 to 55 mol% of all components are alcohol components,
55 to 45 mol% is an acid component.

As the alcohol component, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol,
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, or a bisphenol derivative represented by the formula (a);

[0086]

[Chemical 1]

Further, diols represented by the formula (b):

[0088]

[Chemical 2] And diols such as glycerin, sorbit, sorbitan, and the like.

As the divalent carboxylic acid containing 50 mol% or more of all the acid components, benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and phthalic anhydride or their anhydrides; succinic acid, adipic acid, sebacine Acids, alkyl dicarboxylic acids such as azelaic acid or anhydrides thereof, and succinic acid substituted by an alkyl group having 6 to 18 carbon atoms or anhydrides thereof; fumaric acid, maleic acid, citraconic acid, itaconic acid, or the like. Examples thereof include saturated dicarboxylic acids or anhydrides thereof, and as trivalent or higher carboxylic acids, trimellitic acid, pyromellitic acid,
Examples thereof include benzophenone tetracarboxylic acid and its anhydride.

The alcohol component of the polyester resin particularly preferred in the practice of the present invention is a bisphenol derivative represented by the above formula (a), and the acid component is phthalic acid, terephthalic acid, isophthalic acid or its anhydride, and succinic acid. , N-dodecenyl succinic acid or its anhydride, dicarboxylic acids such as fumaric acid, maleic acid and maleic anhydride; trimellitic acid or its tricarboxylic acid anhydride.

This is because the polyester resin obtained from these acids and alcohols has good fixability as a heat roller fixing toner and excellent offset resistance.

The acid value is 90 or less, preferably 50.
Hereinafter, it is desirable that the OH value is 50 or less, preferably 30 or less. This is because when the number of terminal groups of the molecular chain is increased, the toner depends on the environment for the charging characteristics of the toner.

Further, the glass transition temperature of the polyester resin obtained here is 50 to 75 ° C., preferably 55 to 65.
C., and number average molecular weight Mn 1,500 to 50,000
Preferably 2,000-20,000, weight average molecular weight Mw 6,000-100,000, preferably 10,000.
It is preferably 0 to 90,000.

The electrostatic image developing toner of the present invention may contain a charge control agent, if necessary, in order to further stabilize the chargeability thereof. The charge control agent is the binder resin 100.
0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight
It is preferred to use parts by weight.

Charge control agents known in the art today include the following.

To control the toner to be negatively charged,
For example, organic metal complexes and chelate compounds are effective. Examples thereof include monoazo metal complexes, aromatic hydroxycarboxylic acids, metal complexes, and aromatic dicarboxylic acid-based metal complexes. In addition, aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters,
Examples thereof include phenol derivatives of bisphenol.

When a positively chargeable toner is prepared, nigrosine, a triphenylmethane compound, a rhodamine dye, polyvinyl pyridine or the like may be used as the charge control agent exhibiting the positive chargeability. Further, in the case of producing a color toner, 0.1 to 40 mol%, preferably 1 to 3 mol%, of an aminocarboxylic acid-containing ester such as dimethylaminomethyl methacrylate having a positive charging property as a monomer.
Use a binder resin containing 0 mol%, or
A colorless or light-colored positive charge control agent that does not affect the color tone of the toner may be used. Examples of the positive charge control agent include quaternary ammonium salts represented by structural formulas (A) and (B).

[0098]

[Chemical 3]

[0099]

[Chemical 4]

Among the quaternary ammonium salts represented by the structural formulas (A) and (B), the positive charge control agents represented by the structural formulas (A) -1 and -2 and the structural formula (B) -1 are used. Are preferable because they show good chargeability with little environmental dependence.

[0101]

[Chemical 5]

[0102]

[Chemical 6]

[0103]

[Chemical 7]

In the case where an aminocarboxylic acid-containing ester such as dimethylaminomethyl methacrylate, which exhibits positive charging characteristics, is used as the resin component of the binder resin in the positive charging toner, a positive charge control agent or a negative charge control agent is used. Use as needed.

In the case where the amino-containing carboxylic acid ester such as dimethylaminomethyl methacrylate showing a positive charging characteristic is not used as the resin component in the positively chargeable toner, the positive charge control agent is added to 100 parts by weight of the binder resin. 0.1 to 15
It is desirable to use parts by weight, preferably 0.5 to 10 parts by weight. Further, when the aminocarboxylic acid-containing ester is used, a positive charge control agent and / or a negative charge control agent may be added to 100 parts by weight of the binder resin for the purpose of providing good chargeability with little environmental dependence. It is desirable to use 0 to 10 parts by weight, preferably 0 to 8 parts by weight.

When the toner of the present invention is used as a magnetic toner, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, maghemite and ferrite, and iron oxides containing other metal oxides; Fe, Co and Ni. Like metals, or these metals and Al, Co, Cu, P
b, Mg, Ni, Sn, Zn, Sb, Be, Bi, C
Examples thereof include alloys with metals such as d, Ca, Mn, Se, Ti, W and V, and mixtures thereof.

Conventionally, as a magnetic material, ferric tetroxide (F
e₃ O_Four ), Ferric oxide (γ-Fe)₂ O₃ ), Iron oxide
Lead (ZnFe₂ O_Four ), Yttrium iron oxide (Y₃ Fe
_Five O ₁₂), Cadmium iron oxide (CdFe₂ O_Four ), Oxidation
Iron Gadolinium (Gd₃ Fe_Five -O₁₂), Iron oxide copper (C
uFe₂ O_Four ), Iron oxide lead (PbFe)₁₂-O₁₉), Oxidation
Iron Nickel (NiFe₂ O_Four ), Iron neodymium oxide (Nd
Fe₂ O₃ ), Iron oxide barium (BaFe₁₂O₁₉),
Iron oxide magnesium (MgFe₂ O_Four ), Iron oxide manga
(MnFe₂ O_Four ), Lanthanum iron oxide (LaFeO
₃ ), Iron powder (Fe), cobalt powder (Co), nickel powder
(Ni) and the like are known, but according to the present invention,
Magnetic materials can be used alone or in combination of two or more
To do. A particularly suitable magnetic material for the purposes of the present invention is ferric tetroxide.
Alternatively, it is a fine powder of γ-iron sesquioxide.

These ferromagnetic materials have an average particle size of 0.1 to 2
The magnetic characteristics under the application of 10 K oersted are about 20 μm to 20 oersted coercive force and 50 to 200 eersted saturation magnetization at about μm.
Those having a mu / g (preferably 50 to 100 emu / g) and a residual magnetization of 2 to 20 emu / g are desirable.

For 100 parts by weight of the binder resin, 1 part of the magnetic material is used.
It is recommended to use 0 to 200 parts by weight, preferably 20 to 150 parts by weight.

Carbon black, titanium white, and any other pigments and / or dyes can be used as the colorant regardless of whether it is a single component or a two component. For example, when the toner of the present invention is used as a magnetic color toner, the dye may be C.I. I. Direct Red 1,
C. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Mordant Red 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I.
I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Mordant Blue 7, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. There are Basic Green 6 etc. Examples of pigments include yellow lead, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hansa yellow G, permanent yellow NCG, tartrazine lake, red lead yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, benzidine orange G. , Cadmium Red, Permanent Red 4R, Watching Red Calcium Salt, Eosin Lake, Brilliant Carmine 3B, Manganese Purple, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkali Blue Lake, Victoria Blue Lake, Phthalocyanine Blue,
First Sky Blue, Indren Sren Blue BC,
Chrome Green, Chrome Oxide, Pigment Green B,
Malachite Green Lake, Final Yellow Green G, etc.

When the toner of the present invention is used as a two-component full-color toner, the followings are listed. Examples of magenta color pigments include C.I. I. Pigment Red 1,2,3,4,5,6,7,8,9,1
0,11,12,13,14,15,16,17,1
8, 19, 21, 22, 23, 30, 31, 32, 3
7, 38, 39, 40, 41, 48, 49, 50, 5
1, 52, 53, 54, 55, 57, 58, 60, 6
3,64,68,81,83,87,88,89,9
0,112,114,122,123,163,20
2,206,207,209, C.I. I. Pigment violet 19, C.I. I. Bat red 1, 2, 10, 1
3, 15, 23, 29, 35 and the like.

Although such a pigment may be used alone, it is more preferable from the viewpoint of the image quality of a full-color image to improve the sharpness by using a dye and a pigment in combination. Examples of such magenta dyes include C.I. I. Solvent Red 1,
3,8,23,24,25,27,30,49,81,
82, 83, 84, 100, 109, 121, C.I. I.
Disperse Red 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil soluble dyes such as Disperse Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18,
22, 23, 24, 27, 29, 32, 34, 35, 3
6,37,38,39,40, C.I. I. Basic Violet 1,3,7,10,14,15,21,25
Basic dyes such as 26, 27 and 28 can be mentioned.

Other color pigments include cyan color pigments such as C.I. I. Pigment Blue 2, 3, 15,
16, 17, C.I. I. Bat Blue 6, C.I. I. Acid Blue 45 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted in the phthalocyanine skeleton having the structure represented by the chemical formula 3 or the like.

[0114]

[Chemical 8]

As the coloring pigment for yellow, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10,
11, 12, 13, 14, 15, 16, 17, 23, 6
5, 73, 83, C.I. I. Bat yellow 1,3,20
Etc.

The amount of the colorant used is 0.1 to 60 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the binder resin.
0 parts by weight.

Further, in the present invention, one or more releasing agents may be contained in the toner, if desired.

The releasing agent used in the present invention includes the following. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax and paraffin wax, and oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; carnauba Examples thereof include waxes containing a fatty acid ester as a main component such as wax, sazol wax, and montanic acid ester wax, and those obtained by partially or entirely deoxidizing fatty acid ester such as deoxidized carnauba wax.
Further, saturated straight chain fatty acids such as palmitic acid, stearic acid, and montanic acid, unsaturated fatty acids such as brundic acid, eleostearic acid, and vinalinaric acid, stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubayl alcohol, ceryl. Alcohol, saturated alcohols such as melicyl alcohol, polyhydric alcohols such as sorbitol, fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebis Saturated fatty acid bisamides such as lauric acid amide and hexamethylene bisstearic acid amide, ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipic acid amide, N, N ' Unsaturated fatty acid amides such as dioleyl sebacic acid amide, aromatic bisamides such as m-xylene bisstearic acid amide, N, N′-distearyl isophthalic acid amide, calcium stearate, calcium laurate, zinc stearate, Fatty acid metal salts such as magnesium stearate (generally called metal soap), waxes obtained by grafting aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid, and behenin. Examples thereof include partial esterified products of fatty acids such as acid monoglyceride and polyhydric alcohols, and methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and the like.

The amount of the release agent used in the present invention is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the binder resin.

Further, these releasing agents are usually contained in the binder resin by a method of dissolving the resin in a solvent, raising the temperature of the resin solution, and adding and mixing while stirring, or a method of mixing at the time of kneading.

As the negatively chargeable fluidizing agent used in the present invention, any agent can be used as long as the fluidity can be increased by adding it to the colorant-containing resin particles as compared with before and after addition. It is possible. For example, vinylidene fluoride fine powder, fluororesin powder such as polytetrafluoroethylene fine powder, fine silica powder such as wet-process silica, dry-process silica, etc., those silica as silane coupling agent, titanium coupling agent, silicon oil, etc. There is a treated silica which has been subjected to a surface treatment by.

A preferable fluidizing agent is a fine powder produced by vapor phase oxidation of a silicon halogen compound,
It is so-called dry process silica or fumed silica and is produced by a conventionally known technique. For example, the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxyhydrogen flame is utilized, and the basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl Further, in this manufacturing process, by using another metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound, a fine powder of a composite of silica and another metal oxide is obtained. It is also possible to obtain the body, including them. The particle size is 0.0 as the average primary particle size.
It is desirable to be in the range of 01 to 2 μm, and it is particularly preferable to use fine silica powder in the range of 0.002 to 0.2 μm.

Examples of commercially available silica fine powders produced by vapor phase oxidation of a silicon halogen compound used in the present invention include those commercially available under the following trade names.

AEROSIL (Japan Aerosil Co.) 130 200 300 380 TT600 MOX170 MOX80 COK84 Ca-O-SiL (CABOT Co.) M-5 MS-7 MS-75 HS-5 EH-5 Wacker HDK N 20 V15 (WACK). -CHEMIE GMBH) N20E T30 T40 D-C Fine Silica (Dow Corning Co.) Francol (Fransil)

Further, it is more preferable to use a treated silica fine powder obtained by subjecting the silica fine powder produced by vapor-phase oxidation of the silicon halogen compound to a hydrophobic treatment. Among the treated silica fine powders, those obtained by treating the silica fine powder so that the degree of hydrophobicity measured by the methanol titration test is in the range of 30 to 80 are particularly preferable.

As a method of hydrophobizing, it is imparted by chemically treating with an organic silicon compound or the like which reacts with or physically adsorbs on silica fine powder. As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound.

Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyl. Dimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxy Silane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyl Disiloxane, 1,3-diphenyltetramethyldisiloxane and 2 to 12 per molecule
For example, there is dimethylpolysiloxane having siloxane units and each terminal unit having a hydroxyl group bonded to Si. These are used alone or as a mixture of two or more.

As the positively chargeable fluidizing agent used in the present invention, the above-mentioned dry process silica treated with a coupling agent having an amino group shown below or a silicone oil is used.

[0130]

[Chemical 9]

[0131]

[Chemical 10]

As the silicone oil, an amino-modified silicone oil having a partial structure having an amino group in the side chain of the following formula is generally used.

[0133]

[Chemical 11]

(Wherein R ₁ represents hydrogen, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, and R ₃ and R ₄ represent hydrogen, an alkyl group or an aryl group. However, the above-mentioned alkyl group, aryl group, alkylene group, and phenylene group may contain an amine, and may have a substituent such as halogen within a range not impairing the charging property. A positive integer is shown.) Examples of such silicone oil having an amino group are as follows.

Viscosity at 25 ° C. Amine equivalent Product name (cps) SF8417 (Tore Silicone Co., Ltd.) 1200 3500 KF393 (Shin-Etsu Chemical Co., Ltd.) 60 360 KF857 (Shin-Etsu Chemical Co., Ltd.) 70 830 KF860 (Shin-Etsu Chemical Co., Ltd.) 250 7600 KF861 (Shin-Etsu Chemical Co., Ltd.) 3500 2000 KF862 (Shin-Etsu Chemical Co., Ltd.) 750 1900 KF864 (Shin-Etsu Chemical Co., Ltd.) 1700 3800 KF865 (Shin-Etsu Chemical Co., Ltd.) 90 4400 KF369 (Shin-Etsu Chemical Co., Ltd.) 20 320 KF383 (Shin-Etsu Chemical Co., Ltd.) 20 320 X-22-2680 (manufactured by Shin-Etsu Chemical Co., Ltd.) 90 8800 X-22-380D (manufactured by Shin-Etsu Chemical Co., Ltd.) 2300 3800 X-22-3801C (manufactured by Shin-Etsu Chemical Co., Ltd.) 3500 3800 X-22-2810B (manufactured by Shin-Etsu Chemical Co., Ltd.) Shin-Etsu Gakusha, Ltd.) 1300 1700

The amine equivalent is the equivalent per amine (g / eqiv) and is the value obtained by dividing the molecular weight by the number of amines per molecule.

As the fluidizing agent used in the present invention, those having a specific surface area of 30 m ² / g or more, preferably 50 m ² / g or more by nitrogen adsorption measured by the BET method give good results. Fluidizing agent 0.01 per 100 parts by weight of toner
-8 parts by weight, preferably 0.1-4 parts by weight.

The positively chargeable inorganic fine powder used in the present invention includes metal oxides such as magnesium, zinc, aluminum, cobalt, copper, cerium, yttrium, manganese, bismuth and strontium; calcium titanate, barium titanate, Complex metal oxides such as strontium titanate; and calcium carbonate, barium sulfate, and the like. Of these, zinc oxide, aluminum oxide, cobalt oxide, cerium oxide, strontium titanate, bismuth oxide, and calcium carbonate are preferable because the effects of the present invention can be exhibited more effectively.

The negatively chargeable inorganic fine powder used in the present invention includes molybdenum, tungsten, tantalum, niobium, germanium, vanadium, silicon, titanium, tin, iron, chromium, zirconium, and other metal oxides; titanium, zirconium, Metal silicides such as niobium, tantalum, molybdenum, and tungsten; titanium, zirconium,
Examples thereof include metal nitrides such as vanadium, niobium and tantalum; metal carbides such as titanium, zirconium, vanadium, niobium, tantalum, molybdenum and tungsten; and the like. Of these, molybdenum trioxide, tungsten trioxide, zirconium oxide, titanium silicide, and titanium carbide are preferable because they can exhibit the effects of the present invention.

In the case of a metal oxide, the inorganic fine powder used in the present invention is, for example, produced by a sintering method, mechanically pulverized, and then classified by wind classification to have a desired particle size and particle size distribution. .

The inorganic fine powder used in the present invention is the toner 100.
0.01 to 20 parts by weight, preferably 0.
It is preferable to use 1 to 10 parts by weight.

As the negatively chargeable organic fine powder used in the present invention, negatively chargeable resin fine particles are preferably used. Examples of the negatively chargeable resin include vinyl resins and polyester resins described above as the binder resin for toner, as well as epoxy resin, phenol resin, fluororesin, and silicon resin.

In the present invention, a negative charge control agent used for toner can be used for the purpose of improving the negative chargeability of the resin in order to sufficiently exert its effect. The amount of the negative charge control agent used is preferably 20 parts by weight or less per 100 parts by weight of the negatively chargeable resin.

As the positively chargeable organic fine powder used in the present invention, positively chargeable resin fine particles are preferably used. As the positively chargeable resin, a vinyl resin obtained by polymerizing a part or all of a monomer having an amino group such as polymethylmethacrylate resin, dimethylaminomethylmethacrylate, dimethylaminoethylmethacrylate, and p-dimethylaminostyrene. Examples include polyamide resins.

Here, as in the above case, the positive charge control agent used for the toner can be used to improve the positive charge. When the positive charge control agent is used, a vinyl resin prepared by using a monomer having no amino group may be used. The amount of the positive charge control agent used is resin 1
20 parts by weight or less per 100 parts by weight is desirable.

The method for producing the organic fine powder used in the present invention is as follows:
The desired particle size is obtained by adjusting the particle size by emulsion polymerization method, suspension polymerization method, spray drying method, or by crushing and classifying the resin obtained by emulsion polymerization, solution polymerization, condensation polymerization, etc. And the like.

To prepare the toner for developing an electrostatic charge image of the present invention, a binder resin, a colorant and / or a magnetic material, a charge control agent or other additives are sufficiently mixed with a mixer such as a Henschel mixer or a ball mill. Then, using a heat kneader such as a heating roll, a kneader, or an extruder, the resins are mutually compatibilized by melting, kneading, and kneading meat, and the solidified product is crushed after cooling and solidifying the melt-kneaded product. The toner of the present invention can be obtained by classification.

Further, the fluidizing agent charged to the same polarity as the toner, the inorganic fine powder and the organic fine powder charged to the opposite polarity to the toner, and the toner are sufficiently mixed by a mixer such as a Henschel mixer, and then the toner particles are formed on the surface of the toner particles. The developer for developing an electrostatic charge image of the present invention having an additive can be obtained.

(1) Measurement of Particle Size Distribution The particle size distribution can be measured by various methods, but in the present invention, it was measured using a Coulter counter multisizer.

That is, a Coulter counter Multisizer II type (manufactured by Coulter) was used as a measuring device, and an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution and a CX-1 personal computer (manufactured by Canon) were connected. Then, as the electrolytic solution, a 1% NaCl aqueous solution is prepared by using special grade or primary grade sodium chloride. As a measuring method, a surfactant, preferably 0.1 to 5 ml of alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2
Add ~ 20 mg. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and a 100 μm aperture is used when measuring the toner particle size as an aperture by the Multisizer II type Coulter Counter. 13μ when measuring the particle size of inorganic fine powder
Measurement is performed using the m aperture. The volume and number of the toner and the inorganic fine powder were measured, and the volume distribution and the number distribution were calculated. Then, the weight-based weight average diameter obtained from the volume distribution according to the present invention is obtained from the volume distribution.

The particle size of the organic fine powder was observed under an optical microscope with a CCD camera at a magnification of × 1000 to × 4000 and was 5
The particle size of 00 or more particles was calculated, and the average value was defined as the length average particle size.

(2) Measurement of triboelectric charge amount: FIG. 3 is an explanatory view of the triboelectric charge amount measuring device.

Measurement of triboelectric charge of magnetic toner: Passes through 200 mesh, does not pass through 300 mesh,
The sieved iron powder and the magnetic toner were weighed in a weight ratio of 95: 5, allowed to stand in a measuring environment having a temperature of 23 ° C. and a humidity of 60% for 12 hours or more, and then put in a polyethylene bottle, sufficiently mixed and stirred. To do.

Next, a conductive screen 3 having a bottom of 500 mesh (the size can be appropriately changed so that magnetic particles do not pass through)
A measurement sample is put in a metal-made measuring container 2 having a metal, and the lid 4 made of metal is placed. At this time, the weight of the entire measuring container 2 is weighed and designated as W ₁ (g). Next, in the suction device 1 (at least the portion in contact with the measurement container 2 is an insulator), suction is performed from the suction port 7 to adjust the air volume control valve 6 to adjust the pressure of the vacuum gauge 5 to 250.
mmAq. In this state, suction is sufficiently performed (for about 2 minutes) to remove the toner by suction. The potential of the electrometer 9 at this time is V (volt). Here, 8 is a capacitor, and the capacitance is C (μF). The weight of the entire measuring container after suction is weighed and is W ₂ (g). This triboelectric charge amount T (μ
C / g) is calculated by the following formula.

T (μC / g) = (C × V) / (W ₁ −W ₂ ).

98: 2 The iron powder and the fluidizing agent or the organic fine powder in the measurement of the triboelectric charge amount of the fluidizing agent and the organic fine powder were mixed with 98: 2.
The amount of charge was determined in the same manner as in, except that the weight ratio was set to.

Measurement of Triboelectric Charge of Inorganic Fine Powder A kneaded product obtained by cooling and solidifying the kneaded product in the production of the magnetic toner is roughly crushed and passed through 200 mesh to obtain a kneaded coarse crushed product which does not pass through 300 mesh. The amount of charge was determined in the same manner as in the above except that the kneaded and crushed product and the inorganic fine powder were mixed in a weight ratio of 95: 5 to prepare a measurement sample. However, the charge amount was expressed as a volume conversion value calculated from the specific gravity.

(3) Glass Transition Temperature Tg In the present invention, the measurement is carried out using a differential thermal analysis measuring device (DSC measuring device), DSC-7 (manufactured by Perkin Elmer Co.).

A measurement sample is 5 to 20 mg, preferably 10
Precisely weigh mg.

This was placed in an aluminum pan, and an empty aluminum pan was used as a reference, and the measurement temperature range was 30 to 20.
The measurement is performed at a temperature rising rate of 10 ° C / min between 0 ° C and normal temperature and normal humidity.

During this temperature rising process, the endothermic peak of the main peak in the temperature range of 40 to 100 ° C. is obtained.

At this time, the intersection of the line at the midpoint of the baseline before and after the appearance of the endothermic peak and the differential heat curve is taken as the glass transition temperature Tg in the present invention.

(4) Measurement of molecular weight In the present invention, the molecular weight of the chromatogram by GPC (gel permeation chromatography) is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) as a solvent was flowed through the column at this temperature at a flow rate of 1 ml / min to obtain a sample concentration of 0.05 to 0.6 wt. Inject 50 to 200 μl of a THF sample solution of the resin adjusted to 100% for measurement. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical
Co. Made or manufactured by Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6
X10 ² , 2.1 x 10 ³ , 4 x 10 ³ , 1.75 x 1
0 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10
^It is suitable to use ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ standard polystyrene samples at least about 10 points. In addition, the detector is RI
A (refractive index) detector is used.

As the column, 10 ³ to 2 × 10
^In order to accurately measure the molecular weight region of ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns.
.mu.-styragel 500,10 manufactured by Aters Inc.
Combination of ³ , 10 ⁴ , 10 ⁵ and sho made by Showa Denko KK
dex KF-80M and KF-801, 803, 80
4,805 combination, KA-802,803,804
Combination of 805 or TSKgel made by Toyo Soda
G1000H, G2000H, G2500H, G300
0H, G4000H, G5000H, G6000H, G
A combination of 7000H and GMH is preferable.

[0166]

EXAMPLES The present invention will be described below with reference to production examples and examples.

[Production Example of Strontium Titanate] 600 g of strontium carbonate and 320 g of titanium oxide were wet mixed in a ball mill for 8 hours and then filtered and dried. This mixture was molded under a pressure of 5 Kg / cm ² and calcined at a temperature of 1100 ° C. for 8 hours.

After that, it was mechanically crushed and the weight average diameter was 1.8 μm.
m, length average diameter 0.7 μm, particle size distribution [(m-D ₄ ) /
(M-D ₁ )] 2.6 strontium titanate fine powder was obtained. This is designated as strontium titanate A. The volume distribution and number distribution of strontium titanate A are shown in FIG. An elbow jet classifier utilizing the Coanda effect is used to remove coarse powder and fine powder at the same time to obtain a weight average diameter of 1.4 μm, a length average diameter of 1.0 μm, and a particle size distribution [(m-
D ₄ ) / (m-D ₁ )] 1.4 strontium titanate I was obtained. The volume distribution and number distribution of strontium titanate I are shown in FIG. The charge amount of this strontium titanate I was +4.5 μC / cm ³ .

[Production Example of Aluminum Oxide] Aluminum hydroxide was molded at a pressure of 1000 Kg / cm ² to give 16
It was sintered at a temperature of 00 ° C. for 2 hours. Then, by mechanical pulverization and classification with an elbow jet classifier, a weight average diameter of 4.0 μm, a length average diameter of 2.5 μm, and a particle size distribution [(m-
_{D 4) / (m-D} 1)] to give 1.6 aluminum oxide. The charge amount of this aluminum oxide is +5.6 μC / c
It was m ³ .

[Production Example of Calcium Carbonate] The precipitate formed by blowing carbon dioxide into lime milk was filtered, dried and ground, and then classified by an elbow jet classifier to obtain a weight average particle diameter of 3.5 μm and a long particle size. A calcium carbonate having an average particle size of 1.7 μm and a particle size distribution [(m-D ₄ ) / (m-D ₁ )] 2.1 was obtained. The charge of this calcium carbonate is +
It was 2.5 μC / cm ³ .

[Production Example of Molybdenum Trioxide] Ammonium molybdate was heated with nitric acid to obtain molybdenum oxide. This was filtered, washed with water, dried, and further calcined in the air at 400 ° C. for 6 hours to obtain a powder of molybdenum trioxide.
After that, it was mechanically pulverized to have a weight average diameter of 2.3 μm, a length average diameter of 0.8 μm, and a particle size distribution [(m-D ₄ ) / (m-D ₁ )].
A fine molybdenum trioxide powder of 2.9 was obtained. An elbow jet classifier utilizing the Coanda effect was used to remove coarse powder and fine powder at the same time to obtain a weight average diameter of 1.8 μm, a length average diameter of 1.0 μm, and a particle size distribution [(m−D ₄ ) / (m -D
₁ )] Molybdenum trioxide Mo-I of 1.8 was obtained.

The charge amount of this molybdenum trioxide Mo-I was -21 μC / cm ³ .

[Production Example of Tungsten Trioxide] Tungsten trioxide was obtained by firing metallic tungsten in oxygen at 700 ° C. for 10 hours. After that, it is mechanically pulverized to have a weight average diameter of 4.0 μm, a length average diameter of 1.0 μm, and a particle size distribution [(m
_{-D 4) / (m-D} 1)] 4.0 was obtained three fine powder of tungsten oxide. An elbow jet classifier utilizing the Coanda effect is used to remove coarse powder and fine powder at the same time to obtain a weight average diameter of 3.0 μm, a length average diameter of 2.0 μm, and a particle size distribution [(m−D ₄ ) / (m -D ₁ )] 1.5 tungsten trioxide Wo-I was obtained.

The charge amount of this tungsten trioxide Wo-I was -9 μC / cm ³ .

[Production Example of Organic Fine Powder] [Production Example 1 of Positively Chargeable Organic Fine Powder] Styrene 75 parts by weight Butyl acrylate 10 parts by weight Dimethylaminomethyl methacrylate 15 parts by weight Benzoyl peroxide 3 parts by weight

The above material was dissolved in toluene and heated at 80 ° C.
It was polymerized for 16 hours. Toluene is removed, dried, crushed,
Classified to the length average particle diameter was obtained (p-D ₁₎ 0.6μm organic fine powder I. The charge amount of this organic fine powder I is +70 μC
/ G.

[Production Example 2 of positively chargeable organic fine powder] Styrene 90 parts by weight n-Butyl acrylate 10 parts by weight Benzoyl peroxide 4 parts by weight

The above materials were dissolved in toluene and heated at 80 ° C. for 1 hour.
It was polymerized for 6 hours. After removing toluene and drying, the positive charge control agent represented by the structural formula (A) -1 was kneaded, pulverized, classified at 130 ° C. using 10 parts by weight with respect to 100 parts by weight of the resin, and the length was adjusted. to give an average particle size (p-D ₁₎ 0.2μm organic fine powder II. The charge amount of this organic fine powder is +35
It was μC / g.

[Production Example 1 of negatively chargeable organic fine powder] Styrene 75 parts by weight n-Butyl acrylate 10 parts by weight Monobutyl maleate 15 parts by weight Benzoyl peroxide 4 parts by weight

The above materials were dissolved in toluene and heated at 80 ° C.
It was polymerized for 16 hours. Toluene is removed, dried, crushed,
Classified to the length average particle diameter was obtained (p-D ₁₎ 0.7μm organic fine powder III. The charge amount of this organic fine powder is −50 μm.
It was C / g.

[Production Example 2 of negatively chargeable organic fine powder] A resin was obtained in the same manner as the organic fine powder II, and 5 parts by weight of a monoazo metal complex (negative charge controlling agent) was added to 100 parts by weight of this resin. It was kneaded, pulverized and classified at 130 ° C. to obtain an organic fine powder IV having a length average particle diameter (p-D ₁ ) of 0.1 μm.
The charge amount of this organic fine powder was −45 μC / g.

[Binder Resin Production Example 1] Styrene 85.0 parts by weight Butyl acrylate 15.0 parts by weight Di-tert-butyl peroxide 6.0 parts by weight

The above materials were added dropwise to 200 parts by weight of xylene heated to the reflux temperature over 4 hours. Further, the polymerization was completed under reflux of xylene (138 to 144 ° C.), and xylene was removed while raising the temperature to 200 ° C. under reduced pressure. The resin thus obtained is called resin A.

Resin A 40.0 parts by weight Styrene 45.0 parts by weight Butyl acrylate 15.0 parts by weight Divinylbenzene 0.5 parts by weight Benzoyl peroxide 1.5 parts by weight

170 parts by weight of water in which 0.12 parts by weight of a partially saponified polyvinyl alcohol was dissolved was added to the above mixture, and the mixture was vigorously stirred to give a suspension dispersion. The suspension dispersion was added to a reactor containing 50 parts by weight of water and replaced with nitrogen, and a suspension polymerization reaction was carried out at a reaction temperature of 80 ° C. for 8 hours. After the reaction was completed, it was washed with water, dehydrated and dried to obtain a resin B.

The binder resin B had a glass transition point of 61 ° C., a gel content of 27%, a number average molecular weight Mn of 12,000 and a weight average molecular weight Mw of 100,000. The gel content was determined from the dry weight of the insoluble matter after 0.5 to 1.0 g of the binder resin was weighed using a Soxhlet extractor and the extraction was performed for 6 hours. The molecular weights Mw and Mn were measured using those excluding the gel content.

Binder Resin Production Example 2 Bisphenol Derivative Represented by Formula (A) 1320 parts by weight Fumaric acid 100 parts by weight Terephthalic acid 200 parts by weight Trimellitic acid 300 parts by weight

The above materials were placed in a 4-neck round bottom flask in a 3 liter container equipped with a thermometer, a stainless steel stirrer, a glass nitrogen inlet tube and a falling condenser. Then place the flask in the mantle heater,
Nitrogen gas was introduced through the glass introduction tube to maintain an inert atmosphere in the reactor, the temperature was raised, and dehydration condensation was performed at 220 to 250 ° C. The relationship between the viscosity and the molecular weight was grasped in advance, and when it reached a predetermined viscosity, it was cooled and solidified to obtain a binder resin C.

The glass transition point Tg of this binder resin C is 60.
Number average molecular weight Mn 7,800, weight average molecular weight M
The w was 22,000.

Example 1 Resin B (binder resin) 100 parts by weight Magnetic iron oxide 80 parts by weight (average particle size 0.15 μm, Hc115 Oersted, σs80 emu / g, σr11 emu / g) Low molecular weight ethylene-propylene copolymer 4 Part by weight Monoazo metal complex (negative charge control agent) 2 parts by weight

The above materials were premixed with a Henschel mixer, and then melt-kneaded at 130 ° C. with a twin-screw kneading extruder. After allowing the kneaded product to cool, after roughly crushing with a cutter mill,
It is crushed by using a fine crusher using a jet stream, and further classified by using an air classifier to obtain a weight average particle diameter (t-D ₄ ).
9.0 .mu.m, a length mean diameter (t-D ₁₎ 7.0μm, the distribution _{[(t-D 4) /} (t-D 1)] 1.3 black fine powder (negative frictional chargeable magnetic toner) Got The volume distribution and number distribution of the obtained magnetic toner are shown in FIG.

With respect to 100 parts by weight of this magnetic toner, 0.6 part by weight of hydrophobic dry silica (BET 150 m ² / g), 3.0 parts by weight of strontium titanate I, and organic fine powder I
0.3 part by weight was externally added by a Henschel mixer to obtain a developer.

Using the obtained developer, a photosensitive drum of a Canon laser copying machine NP9330 was converted into an OPC photosensitive drum, and a latent image was formed with a laser after charging with a negative corona, and reversal development was carried out. Images were evaluated with a modified machine.

As a result, there was no fog on the white background and the maximum image density was 1.46.
The density gradation was good. In addition, linearity that was almost satisfactory was obtained in the relationship between the development potential and the image density (FIG. 2). Further, the edge effect can be reduced, and the change in the density of the edge portion in the solid image is also slight.

Further, a copy test of 30,000 sheets was conducted. As a result, good results were obtained in terms of fixing property without toner scattering. The copied image had good image quality with almost no change from the initial image described above. Also,
No scratch was observed on the surface of the organic photoconductor, and the measurement result of the thickness of the photoconductor surface layer due to the ozonized current showed that the abrasion amount of the photoconductor surface layer was 1.6.
It was as small as μm / 10,000 sheets. Further, the particle size of the developer on the developer carrying member was measured, and the weight average particle size was 9.5.
μm, length average particle size 7.3 μm (initial weight average particle size 9.
When the average particle size was 0 μm and the average particle size was 6.8 μm), there was almost no change in particle size and distribution, and good results were obtained in terms of selective developability.

Further, the carrier memory was also small.

Further, a copying test was conducted at low temperature and low humidity (5 ° C., 10%) and high temperature and high humidity (30 ° C., 80%), and good results were obtained as in the initial stage. Further, a long-term storage test (one week storage) test was carried out at high temperature and high humidity, and good results were obtained without a decrease in concentration.

Examples 2 to 3 A developer was prepared in the same manner as in Example 1 except that the material constitution shown in Table 1 and the toner particle size were changed, and the same evaluation as in Example 1 was carried out. The good results shown in are obtained.

[0199]

[Table 1]

[0200]

[Table 2]

Example 4 In the same manner as in Example 1 except that the monoazo metal complex was changed to 2 parts by weight of nigrosine, the weight average particle diameter (t-D ₄ ) was 9.0 μm and the length was the same. Average particle size (t-D ₁ )
A positively chargeable magnetic toner having a distribution of (t-D ₄ ) / (t-D ₁ ) 1.3 and 7.0 μm was obtained.

Silicone oil having an amino group (trade name: KF8) was added to 100 parts by weight of this positively chargeable magnetic toner.
57) treated with AEROSIL 130 (treated with 13 wt% oil relative to silica, BET 120 m ² /
g, the amount of charge was +120 μC / g), 0.5 parts by weight of molybdenum trioxide Mo-I 3.0 parts by weight, and 0.3 parts by weight of organic fine powder III were externally added by a Henschel mixer. Used as a developer.

Using the obtained developer, image development and evaluation were carried out by a machine in which the transfer portion of Canon NP4835 copying machine was modified into roller transfer.

As a result, there was no fog on the white background and the maximum image density was 1.45.
The density gradation was good. In addition, almost satisfactory linearity was obtained in the relationship between the developing potential and the image density.

The edge effect could be reduced, the density change of the edge portion in the solid image was also slight, and there was no hollow defect in the transfer.

Further, a copy test of 30,000 sheets was conducted. As a result, good results were obtained in terms of fixing property without toner scattering. The copied image had good image quality with almost no change from the initial image described above. No scratch was observed on the surface of the organic photoconductor, and the measurement result of the thickness of the photoconductor surface layer due to the ozonized current showed that the abrasion amount of the photoconductor surface layer was 1.8 μm.
It was a very small m / 10,000 sheets. Further, the particle size of the developer on the developer carrying member was measured, and the weight average particle size was 9.6 μ.
m, number average particle size 7.8 μm (initial weight average particle size 9.0
The average particle size was 7.0 μm and the average particle size was 7.0 μm), and there was almost no change in particle size and distribution, and good results were obtained in terms of selective developability.

Further, the carrier memory was also minor.

Further, a copying test was conducted at low temperature and low humidity (5 ° C., 10%) and high temperature and high humidity (30 ° C., 80%), and good results were obtained as in the initial stage. Further, a long-term storage test (one week storage) test was carried out at high temperature and high humidity, and good results were obtained without a decrease in concentration.

Example 5 The same as Example 4 except that the positively chargeable magnetic toner of Example 4 was used, and molybdenum trioxide and organic fine powder III were changed to 3 parts by weight of tungsten trioxide and organic fine powder IV. Then, good results as shown in Table 3 were obtained.

The initial particle diameter of the developer used at this time is 9.0 μm in weight average particle diameter (t-D ₄ ), and average particle diameter in length (t-D ₄ ).
D ₁ ) It was 6.9 μm.

[0211]

[Table 3]

Example 6 Resin B 100 parts by weight Monoazo metal complex (negative charge control agent) 4 parts by weight The same procedure as in Example 1 was carried out using 5 parts by weight of copper phthalocyanine represented by Structural Formula I, and the weight average particle diameter was measured. (T-D
₄ ) 8.0 μm, length average particle diameter (t-D ₁ ) 6.0 μm
m, to obtain a negatively chargeable toner distribution _{(t-D 4) / (} t-D 1) 1.3.

Using this toner, external additives were added in the same manner as in Example 1. Further, as a carrier, a Cu-Zn-Fe-based ferrite carrier (average particle size: 45) coated with 0.5% by weight of styrene-acrylic 2-ethylhexyl-methyl methacrylate (copolymerization weight ratio 50:20:30).
μm, 250 mesh pass 400 mesh on 87% by weight), and a developer was prepared so that the toner concentration would be 6.0% by weight.

Images were evaluated by using a CLC-500 full color copying machine manufactured by Canon Inc. using these developers.

As a result, there was no fog on the white background and the maximum image density was 1.48.
The density gradation was good. In addition, almost satisfactory linearity was obtained in the relationship between the developing potential and the image density.

The edge effect was also reduced, and the density change at the edge portion in the solid image was also slight.

Further, a copy test of 20,000 sheets was conducted. As a result, the toner was not scattered and the toner was easily transported in the copying machine and was stable. Further, good results were obtained in terms of fixing property. The copied image had good image quality with almost no change from the initial image described above. Further, no scratch was observed on the surface of the organic photoconductor, and the result of measuring the thickness of the photoconductor surface layer by the use current was that the amount of abrasion of the photoconductor surface layer was as small as 1.7 μm / 10,000 sheets. Further, the particle size of the developer on the developer carrier was measured, and the weight average particle size was 8.4 μm and the length average particle size was 6.2 μm (initial weight average particle size 8.0 μm, length average particle size 5.9 μm). There was almost no change in particle size and distribution, and good results were obtained in terms of selective developability.

Further, the carrier memory was also good.

Further, a copying test was conducted at low temperature and low humidity (5 ° C., 10%) and high temperature and high humidity (30 ° C., 80%), and good results were obtained as in the initial stage. Further, a long-term storage test (one week storage) test was carried out at high temperature and high humidity, and good results were obtained without a decrease in concentration.

Comparative Examples 1 to 3 Developers were prepared and evaluated in the same manner as in Examples 1 and 4 in the same manner as in Examples 1 and 4 except that the material constitution shown in Table 4 and the toner particle size were changed. The results shown in Table 5 were obtained.

[0221]

[Table 4]

[0222]

[Table 5]

[0223]

The developer for developing an electrostatic image of the present invention is excellent in developing characteristics, and particularly excellent in the effect of suppressing selective development. Further, it is suitable as a developer for developing a latent image formed on an OPC photoconductor using an organic photoconductive substance.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a developing potential and a copy image density when a developer other than the present invention is used, in which a solid line indicates a maximum image density of 1.4 or more and a broken line indicates The case where the density gradation is improved is shown.

FIG. 2 is a diagram showing a relationship between a developing potential and a copy image density when a developer according to the present invention is used.

FIG. 3 is an explanatory diagram of a device for measuring a triboelectric charge amount of toner.

FIG. 4 is a particle size distribution chart (13 μm) of the inorganic fine powder according to the present invention.
m aperture).

FIG. 5 is a particle size distribution chart (13 μm aperture) of the inorganic fine powder before classification.

FIG. 6 is a particle size distribution diagram (100 μm aperture) of the insulating positive toner.

Claims (1)

[Claims] 1. The weight average particle diameter (t-D ₄ ) is ₄ to 12 μm.
m, the length average particle diameter (t-D ₁ ) is ₁ to 10 μm, and the value of (t-D ₄ ) / (t-D ₁ ) is 1.01 to 2
Insulating toner, which is charged with the same polarity as the insulating toner, and which adsorbs N ₂
A fluidizing agent having a specific surface area of 30 m ² / g or more as measured by the T method, which is charged in a polarity opposite to that of the insulating toner, and has a weight average particle size (m
₄ ) is 0.6 to 5 μm, and the average length particle size (m-
D ₁ ) is 0.5 to ₄ μm, and (m−D ₄ ) / (m−
The value of D ₁ ) is 1.0 to 2.4, and (m−D ₄ ) /
Inorganic fine powder in which (m-D ₁ ) is equal to or larger than the value of (t-D ₄ ) / (t-D ₁ ), and is charged in the opposite polarity to the insulating toner, and the average length is obtained. Particle size (p-D
₁ ) A developer for developing an electrostatic charge image, which contains an organic fine powder having a particle size of 0.8 μm or less.