JPH043073A - Color toner - Google Patents

Abstract

PURPOSE:To obtain images which have high image quality and are environmentally stable by forming the color toner in the form of mixing coloring agent- contg. polyester resin particles contg. a specific salt making compd. and a flow improving agent having a specified electrostatic charge quantity. CONSTITUTION:The nonmagnetic coloring agent-contg. polyester resin particles of the insulating nonmagnetic color toner having the nonmagnetic coloring agent-contg. polyester resin particles and the flow improving agent have 4 to 10mum volume average grain size and the constituting components thereof contain a binder resin essentially consisting of a diol component and a dicarboxylic acid component and the salt making compd. expressed by formula I. The flow improving agent has <=20muC/g absolute value of the electrostatic charge quantity when this agent is frictionally electrified with an iron powder carrier. In the formula I, R1 denotes 1 to 8C alkyl group; R2 and R3 denote 1 to 18C alkyl group; R4 denotes 1 to 8C alkyl group, benzyl group. The nega tive chargeable polyester color toner for developing electrostatic charge images which is hardly effected by temp. and humidity environments and have a stable frictional electrification characteristic is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner for dry electrophotography for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, and the like.

BACKGROUND OF THE INVENTION It is well known in the art to form and develop images on the surface of photoconductive materials by electrostatic means.

That is, U.S. Patent No. 2,297,691, Japanese Patent Publication No. 4
A number of methods are known, such as those disclosed in Japanese Patent Publication No. 2-23910 and Japanese Patent Publication No. 43-24748, but generally a photoconductive substance is used to form an electrical latent image on a photoreceptor by various means. Next, a toner image corresponding to an electrostatic latent image is formed by depositing a very finely pulverized electrostatic material called toner on the latent image.

Then, if necessary, the toner is transferred onto the surface of an image support such as paper, and then fixed by heating, pressure, solvent vapor, etc. to obtain a copy. Further, when a step of transferring a toner image is included, a step for removing residual toner is usually provided.

Development methods for visualizing electrical latent images using toner include, for example, the powder cloud method described in U.S. Pat. No. 2,221,776, and the powder cloud method described in U.S. Pat. Cascade development method, No. 2, 874.0
The magnetic brush method described in Japanese Patent No. 3,909,258 and the method using conductive magnetic toner are known.

Toners applied to these developing methods are generally prepared by mixing and dispersing a coloring agent in a thermoplastic resin and then pulverizing the mixture. The most common thermoplastic resin is polystyrene resin, but polyester resin, epoxy resin, acrylic resin, urethane resin, etc. are also used. Carbon black is most widely used as a coloring agent, and in the case of magnetic toner, iron oxide-based black magnetic powder is often used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

The toner image on the final copy imaging member, such as paper, is permanently affixed to the support by heat, pressure, or the like. Traditionally,
This fixing process often uses heat.

Furthermore, when a process for transferring a toner image is included, a process for removing residual toner on the photoreceptor is usually provided.

In recent years, there has been a rapid shift from monochrome copying to full-color copying in copying machines, and two-color copying machines and full-color copying machines are being extensively studied and put into practical use. For example, “Journal of Electrophotography Society J Vol 22. N
o, l (19g3) and “Electronic Photography Society Journal J Vol.
25. No, 1. There are also reports on color reproducibility and gradation reproducibility, such as P52 (1986).

However, unlike television, photographs, and color printed matter, they cannot be directly compared with the real thing, and for people who are used to seeing color images that are more beautifully processed than the real thing, the full-color electrophotographic images that are currently in practical use are not necessarily It has not been a satisfying experience.

Color image formation by full-color electrophotography generally requires 3
All colors are reproduced using toner of three primary colors: yellow, magenta, and cyan.

In this method, light from the original is first passed through a color-separating light transmitting filter that has a complementary color to the toner color to form an electrostatic latent image on the photoconductive layer, and then the toner is transferred to the support through a development and transfer process. hold it. Repeat this process several times in sequence,
After overlapping the toners on the same support while adjusting the registration, a final full-color image is obtained by -times of fixing.

In general, in the case of a so-called two-component development system in which the developer is composed of toner and carrier, the developer charges the toner to the required charge amount and charge polarity by friction with the carrier, and uses electrostatic attraction to create a static image. The toner is used to develop an electric image, and therefore, in order to obtain a good visible image, it is necessary that the toner have good triboelectric charging properties, which is determined mainly by the relationship with the carrier.

Today, in response to the above-mentioned problems, we are searching for carrier core agents and carrier coating agents, optimizing the coating amount, examining charge control agents and fluidity imparting agents to be added to toner, and improving the base binder. Many studies have been conducted to achieve excellent triboelectric charging properties in all materials constituting the developer.

For example, as a technique for adding a charging aid such as chargeable fine particles to toner, Japanese Patent Publication No. 52-32256 and Japanese Patent Application Laid-Open No. 56-64352 disclose fine resin powder having a polarity opposite to that of the toner. Japanese Patent No. 61-160760 proposes a technique in which a fluorine-containing compound is added to a developer to obtain stable triboelectric charging properties, and many charging aids are still being developed today.

Furthermore, various methods for adding the above-mentioned charging aids have been devised. For example, a common method is to make the toner particles adhere to the surface of the toner particles by electrostatic force or van der Waals force between the toner particles and the charging aid, and a stirring machine, a mixer, etc. are used.

However, in this method, it is not easy to uniformly disperse the additive on the surface of the toner particles (also, there is the presence of additives that are not attached to the toner particles and form aggregates with each other, resulting in a so-called free state). It is difficult to avoid.

In such a case, the performance as a developer will be affected.

For example, the amount of triboelectric charge of the toner becomes unstable, resulting in inconsistent image density and images with a lot of fog.

Alternatively, when continuous copying or the like is performed, the content of the charging aid changes, making it impossible to maintain the initial image quality.

Another method of addition is to add a charging aid in advance together with a binder resin and a colorant during toner production. However, it is not easy to make the charge control agent uniform, and it is the substances near the surface of the toner particles that substantially contribute to the chargeability, and the charge aids and charge control agents present inside the particles have a chargeability. Therefore, it is not easy to control the amount of charging aid added or the amount of dispersion on the surface. Furthermore, even in the toner obtained by this method, the amount of triboelectric charge of the toner is unstable, and as mentioned above, it is not easy to obtain a product that satisfies the developer characteristics, so it is not sufficient to simply use a charging aid. The reality is that we are not able to obtain quality products.

Furthermore, in recent years, there has been an increasing demand in the market for high definition and high image quality in copying machines, and attempts have been made in the technical field to achieve high quality color images by reducing the particle size of toner. As the diameter becomes smaller, the surface area per unit weight increases, and the amount of charge on the toner tends to increase, leading to concerns about low image density and deterioration of durability. Join,
Since the amount of charge on the toner is large, the adhesion between the toners is strong and the fluidity is reduced, causing problems in the stability of toner replenishment and the occurrence of triboforming in the replenished toner.

Furthermore, in the case of color toner, since it does not contain a magnetic material or a conductive substance such as carbon black, there is no part that leaks charge, and the amount of charge generally tends to be large. This tendency is particularly noticeable when a polyester binder with high charging performance is used.

In addition, particularly for color toners, the following characteristics are strongly desired.

(1) The fixed toner needs to be almost completely melted to such an extent that the shape of the toner particles cannot be discerned, so that it does not diffusely reflect light and interfere with color reproduction.

(2) The colored toner must have transparency that does not interfere with toner layers of different tones below the toner layer.

(3) Each of the constituent toners must have well-balanced hue and spectral reflection characteristics and sufficient saturation.

From this point of view, many studies have been made regarding binder resins, but toners that satisfy all of the above characteristics have not yet been developed. Today, polyester-based resins are often used as color binder resins in this technical field, but toners made of polyester-based resins are generally easily affected by temperature and humidity. Problems such as insufficient charge amount occur under humid conditions, and there is an urgent need to develop color toners that have a stable charge amount even in a wide range of environments.

[Problems to be Solved by the Invention] An object of the present invention is to provide a negatively chargeable polyester color toner for electrostatic charge development that solves the above-mentioned problems.

That is, the purpose of this research is to provide a negatively chargeable polyester color toner for electrostatic charge development that is not easily influenced by environments such as temperature and humidity and has always stable triboelectric chargeability.

A further purpose of this research is to provide a negatively chargeable polyester color toner for electrostatic charge development that has clear image characteristics without fog and has excellent durability and stability.

A further objective of this research is to provide a negatively chargeable polyester color toner for electrostatic development with good fluidity.

It is characterized by an insulating non-magnetic color toner having at least non-magnetic colorant-containing polyester resin particles and a flow improver, wherein the non-magnetic colorant-containing polyester resin particles have a volume average diameter of 4. ~10 pm, and the constituent components are a binder resin whose main components are a diol component and a dicarboxylic acid component, and a salt-forming compound represented by the following formula... (I), and at least one of the fluidity improvers is , the absolute value of the charge amount when frictionally charged with the iron powder carrier is 20μc/
g or less.

As a result of intensive studies on the environmental stability of the chargeability of negatively chargeable polyester color developers for electrostatic charge development, the present inventors discovered that a salt-forming compound represented by the following formula... (I) is a total binder resin. When at least one of the colorant-containing polyester resin particles and the fluidizing agent, which are contained in an amount of 0.1 to 8 parts by weight, is triboelectrically charged with an iron powder carrier, the absolute value of the charge amount is 2 μc/g or less. The inventors have discovered that a toner in a mixed form with a flow improver has excellent chargeability stability in various environments and provides good images without fogging.

The reason for this is that the charge-up caused by excessive rubbing of the polyester resin as the binder resin with the carrier used in the present invention is neutralized by the above-mentioned positively chargeable salt-forming compound. At this time, the salt-forming compound has a weak positive chargeability, so it cannot prevent the rise of charge on the polyester resin (rather, it has the effect of promoting the rise of charge by rubbing with the salt-forming compound. After the charging of the system resin rises, a function to neutralize the excessive charging is activated, and therefore, the toner having the structure of the present invention has the ability to withstand the rise of charging with the tribo-imparting member and the saturation charge level in various environments. It can be maintained well and stably.

In the present invention, in order to reliably exhibit its performance and have stable negative chargeability, it is preferable that the total binder resin contains 0.1 to 8 parts by weight.

As the salt-forming compound of the present invention, all conventionally known compounds can be used, but specifically, compounds
It is ideal for color toners because it is thermally stable and white in color and melting point.

Conventionally, the inclusion of the above compounds in toner has been disclosed in Japanese Patent Publication No. 1-54694, etc., but these are included solely for the purpose of stabilizing positive charging, and are completely irrelevant to the present invention. This is another invention.

The main components of the binder resin of the polyester resin particles of the present invention are a diol component and a dicarboxylic acid component, and the diol components include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4=butanediol, 2 , 3-butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, 1.
5-bentanediol, 1,6-hexanediol, neopentyl glycol, pentaerythritol diallyl ether, trimethylene glycol, 2-ethyl-1,
3-hexanediol, hydrogenated bisphenol A, and bisphenol derivatives represented by the following formula; is 2
~lO. ) etc.

In addition, the dicarboxylic acid component includes unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or acid anhydrides thereof, and dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or their acid anhydrides. Examples include acid anhydrides, aromatic dicarboxylic acids such as phthalic acid, and terephthalic acid.

(In the formula, R is ethylene or propylene group, x, y
are each an integer of 1 or more, and the average value of x+y is 2 to 10. ) as the diol component, such as fumaric acid,
A polyester resin obtained by cocondensation polymerization with maleic acid, maleic anhydride, phthalic acid, terephthalic acid, etc. is more preferable because it has sharp melting characteristics.

The diol component used in the present invention is preferably 40 to 6
0 moI! %, especially 45-55 mof%, the acid component is 60-40 rno1%, especially 55-45I! lop%
It is desirable that

A charge control agent may be added to the toner according to the present invention in order to stabilize charge characteristics. In this case, a colorless or light-colored charge control agent that does not affect the color tone of the toner is preferred. Examples of negative charge control agents include organometallic complexes such as metal complexes of alkyl-substituted salicylic acid (for example, chromium complexes or zinc complexes of di-tert-butylsalicylic acid). When the negative charge control agent is added to the toner, it is preferably added in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, per 100 parts by weight of the binder resin.

When a two-component developer is mixed with the toner according to the present invention, the mixing ratio is 2 as the toner concentration in the developer.
~10% by weight, preferably 3-9% by weight usually gives good results. If the toner concentration is less than 2% by weight, the image density will be too low to be practical, and if it exceeds 10% by weight, fogging and in-machine scattering will increase and the service life of the developer will be shortened.

As the colorant used in the present invention, known dyes and pigments such as phthalocyanine blue, industhrene blue, peacock blue, permanent red, lake red, rhodamine lake, banza yellow, permanent yellow, benzine yellow, etc. can be widely used. can. The content thereof is 12 parts by weight or less, preferably 0.5 to 9 parts by weight, based on 100 parts by weight of the binder resin so as to sensitively reflect the transparency of the OHP film.

The flow improver used in the present invention has an absolute charge amount of 20 μc/
It is necessary to contain at least one of the following: g or less, preferably 10 μc/g or less. In the case of the present invention, even if the charging ability of the colorant-containing resin particles is stabilized, if silicic acid fine powder, which is generally used as a flow improver, is used alone, the fluidity will certainly improve. As for the charging characteristics, charging tends to become excessive especially at low temperatures, and as a result, the environmental stability of the toner is impaired. This tendency becomes more noticeable as the particle size of the toner is reduced and the amount of fine silicic acid powder used increases.

However, as in the present invention, by containing at least one flow improver with weak charging ability as a flow improver, it was possible to achieve both charging characteristics and fluidity.

Examples of such particles include, but are not necessarily limited to, the following: For example, A
12gOs, Ti0a, Ge0z, ZrO,5c
20s.

Metal oxides such as HfO2, carbides such as SiC, TiC, W, and C, and 5i=N4. There are nitrides such as Ge and N4, among which AI! zOx, Ti0a, 5c
20x, ZrL, Ge0z, and HfO2 are colorless or white, so when used for color toners, they do not adversely affect the color and are suitable. Also, especially A
I! , O, , DxOx, and ZrOz are more preferable because they can be easily produced with a suitable particle size. In addition, the finer the particle size of the particles to be added, the better, and in the present invention, B
The specific surface area (BET specific surface area) measured by the ET method is preferably 30 m"/g to 300 m"7g, J: more preferably 50 m"/g or more (the finer the particle size, the better the flow characteristics of the toner. will be good.

In a more preferred configuration of the present invention, the flow improver having a weak charging ability is a hydrophilic inorganic oxide with a BET specific surface area of 30 to 200 m"7g, and furthermore, the absolute value of the triboelectric charge amount with the carrier is 50 μc/g. With the above, the BET specific surface area is 80
~300 is 7g of negatively charged hydrophobic inorganic oxide and 0.3
It is preferable to use them together in a range of 2% by weight.

As such a hydrophobic inorganic oxide, it is particularly preferable to use treated silica fine powder obtained by hydrophobicizing silica fine powder produced by gas phase oxidation of a silicon halide compound. Among the treated silica fine powders, it is particularly preferred that the silica fine powders be treated so that the degree of hydrophobicity as measured by a methanol titration test is in the range of 30 to 8o.

Hydrophobization is achieved by chemical treatment with an organosilicon compound that reacts with fine silica powder or physically adsorbs it.

In a preferred method, fine silica powder produced by vapor phase oxidation of a silicon halide is treated with an organosilicon compound.

Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane,
Allyl phenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacul -, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyljethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane and 2 per molecule There are dimethylpolysiloxanes having 12 siloxane units and each unit located at the end containing one hydroxyl group bonded to Si. These may be used alone or in a mixture of two or more.

Commercially available products include Taranox-500 (Talco),
Examples include AEROSrL R-972 (Japan Aerosil Co., Ltd.).

The amount added is also related to the particle size distribution of the resin particles described later, but if it is less than 0.3% by weight, it will be difficult to achieve adequate fluidity, and if it is more than 2% by weight, problems such as toner scattering and fogging will occur. easy.

If necessary, additives may be mixed into the color toner of the present invention within a range that does not impair the properties of the toner. Examples of such additives include Teflon, zinc stearate,
Examples include lubricants such as polyvinylidene fluoride, fixing aids (eg, low molecular weight polyethylene, low molecular weight polypropylene, etc.).

In producing the color toner of the present invention, a hot roll,
After thoroughly kneading the constituent materials using a thermal kneader such as a kneader or extruder, the resulting material is obtained by mechanical crushing and classification, or by dispersing materials such as magnetic powder in a binder resin solution and then spray-drying. Alternatively, a method for producing a polymerized toner can be applied, such as a method for producing a toner by mixing a predetermined material with a monomer to constitute a binder resin, and then polymerizing the emulsified suspension.

In the present invention, the volume average particle diameter of the color toner is 6 to 6.
10 pm, and 15 to 40 toner particles of 5 μm or less
Number %, 12.7-16. Contains 0.1 to 5.0 volume% of OILm, 1.0 volume% or less of 16Km or more, 6.3
The effect is more significant when toner particles having a particle size of 5 to 10.1 μm have a particle size distribution that satisfies the following formula.

The toner having the above particle size distribution can faithfully reproduce the latent image formed on the photoreceptor, and has excellent reproducibility of halftone dots and minute dot latent images such as digital ones, and is especially suitable for high-speed toner. Provides an image with excellent gradation and resolution in the light area. Furthermore, it maintains high image quality even when copying or printing is continued, and even in the case of high-density images, it is possible to perform good development with less toner consumption than conventional non-magnetic toner, making it economical. This has advantages in terms of flexibility and miniaturization of the copying machine or printer main body.

The reason why such an effect is obtained in the color toner of the present invention is not necessarily clear, but it is presumed as follows.

Conventionally, in color toners, toner particles of 5 μm or less are difficult to control the amount of charge, impair the fluidity of the toner, and are components that cause the toner to scatter and stain the machine, as well as to cause image fogging. As,
It was considered necessary to actively reduce it.

However, according to studies conducted by the present inventors, it has been found that toner particles of about 5 μm are an essential component for forming high-quality images.

For example, by using a two-component developer having a non-magnetic toner and a carrier having a particle size distribution ranging from 0.5 pm to 30 JLm, the surface potential on the photoreceptor is changed, and a large development potential contrast that allows a large number of toner particles to be easily developed is used. from,
The latent image is developed by changing the potential of the latent image on the photoconductor, and the developed toner particles on the photoconductor are After collecting and measuring the toner particle size distribution,
It was found that there were many toner particles with a diameter of 8 pm or less, and in particular, there were many toner particles with a diameter of about 5 μm on the latent image of minute dots. In other words, when toner particles with a particle size of about 5 μm are smoothly supplied to develop a latent image on a photoreceptor, an image that is faithful to the latent image, does not protrude from the latent image, and has truly excellent reproducibility can be obtained. It is something that can be done.

This is related to the necessity of the presence of non-magnetic toner particles with a particle size of about 5 μm as mentioned above, but non-magnetic toner particles with a particle size of 5 pm or less can certainly reproduce the latent image of minute dots faithfully. However, the toner itself has a fairly high cohesive property, which may impair its fluidity as a non-magnetic toner.

The present inventors attempted to further improve the fluidity by adding two or more of the above-mentioned inorganic oxides as a fluidity improver for the purpose of improving the fluidity, but this resulted in problems such as image density, toner scattering, and fogging. Regarding the conditions for satisfying all items such as
After containing ~40% by number, 12.7~16.0. u
It has been found that by containing 0.1 to 5.0% by volume of n+ toner particles, fluidity can be further improved and high image quality can be achieved. That is, it is thought that this is because it has appropriately controlled fluidity for toner particles in the range of 12.7 to 16.0 μm or non-magnetic toner particles of 5 μm or less, and as a result, it is possible to continue copying or printing. Even at high density, sharp images with excellent resolution and gradation can be provided.

Furthermore, while examining the state of particle size distribution and development characteristics, the present inventors found a state of particle size distribution most suitable for achieving the purpose as shown in the above formula for toner particles of 6.35 to 10.1 μm. We also found that there is.

In other words, when the particle size distribution is adjusted by general wind classification, a large value in the above equation means that the number of toner particles of about 5 pm that faithfully reproduces a minute dot latent image increases, and a small value means that the This is understood to indicate that toner particles of about 5 μm are reduced.

Therefore, when dv is in the range of 6 to 10 μm and the above relational expression is further satisfied, even better toner fluidity and faithful latent image reproducibility can be achieved.

For toner particles with a particle size of 16 μm or more, 1.
It is preferable to make it 0% by volume or less, and as little as possible.

Let me explain in more detail. The non-magnetic toner particles having a particle size of 5 μm or less should account for 15 to 40 percent by number, more preferably 20 to 35 percent by number, of the total number of particles. When the number of non-magnetic toner particles with a particle size of 5 gm or less is less than 15%, there are few non-magnetic toner particles that are effective for high image quality, and especially as the toner is used by continuing copying or printing, the effective non-magnetic toner particles become less effective. As the magnetic toner particle component decreases, the balance of the particle size distribution of the non-magnetic toner as shown in the present invention may deteriorate, and image quality may gradually deteriorate. Furthermore, if the amount exceeds 40% by number, non-magnetic toner particles tend to aggregate with each other,
Toner particles tend to form agglomerates that are larger than the original particle size, resulting in rough image quality, reduced resolution, or a large difference in density between the edges and the inside of the latent image, resulting in a hollow image. .

In addition, particles in the range of 12.7 to 16.0 μm are 0.1 to
The content is preferably 5.0% by volume, preferably 0.2-3
．． 0% by volume is good. When the amount is more than 5.0% by volume, image quality deteriorates and more development than necessary occurs, that is, too much toner is applied, leading to an increase in toner consumption.

On the other hand, if it is less than 0.1% by volume, there is a risk that the image density will decrease due to a decrease in fluidity.

In addition, non-magnetic toner particles with a particle size of 16 μm or more are 1.0
It is preferable that the amount is not more than 0.6% by volume, more preferably not more than 0.6% by volume, and if it is more than 1.0% by volume, it will not only hinder the reproduction of fine lines but also cause problems in the development on the photoreceptor during transfer. The protruding presence of coarse toner particles of 16 pm or more on the surface of the thin layer of toner particles makes the delicate contact between the photoreceptor and the transfer paper via the toner layer irregular and prevents fluctuations in transfer conditions. This tends to cause the transfer of defective images. Further, the volume average diameter of the non-magnetic color toner is 6 to 10 μm, preferably 7 to 9 ILm.
This value cannot be considered separately from each component mentioned above. Volume average particle size 6pm
If the image density is less than On the other hand, it is thought that this is due to the same reason as the reason why the internal concentration decreases.Volume average particle size 10 μm
Above that, the resolution is not good.

The particle size distribution of toner can be measured by various methods.
In the present invention, a Coulter counter was used.

That is, the measuring device is Coulter counter TA-n.
Number distribution using a mold (manufactured by Coulter).

An interface that outputs the volume distribution (manufactured by Nikkaki) and a CX-1 personal computer (manufactured by Canon) are connected, and the electrolyte is 1% Na (J
! Prepare an aqueous solution. As a measurement method, the electrolytic solution 100
~150m! ! Add 0.1 to 5 ml of a surfactant as a dispersant, preferably an alkylbenzene sulfonate, and add the measurement sample to 2 to 20 ml. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic dispersion device, and then using the Coulter Counter Model TA-II as an aperture, using a 100 μm aperture as an aperture, particles of 2 to 40 μm in size were dispersed based on the number of particles. Measure the particle size distribution of
Then, the values related to the present invention were determined.

The color toner of the present invention can be applied to either a -component development method or a two-component development method.

When the color toner of the present invention is used as a two-component developer, an electrically insulating resin is used as a coating resin on the surface of the carrier, which is appropriately selected depending on the toner material and the carrier core material. In the present invention, at least one monomer selected from at least acrylic acid (or its ester) monomer and methacrylic acid (or its ester) monomer is used to improve adhesion to the surface of the carrier core material. It is necessary to contain

In particular, when polyester resin particles with high negative charging ability are used as a toner material, it is preferable to further copolymerize with a styrene monomer in order to stabilize charging, and the copolymerization weight ratio of the styrene monomer is is preferably 5 to 70% by weight.

The average molecular weight of the above copolymer is determined to be a number average molecular weight of 10.
00-35,000 preferably 17,000-24,
(100, weight average molecular weight is 25.001) ~ 100,
000, preferably 49,000 to 55,000.

Examples of monomers for the coating resin of the carrier core material that can be used in the present invention include styrene monomers, chlorostyrene monomers, 〇-methylstyrene monomers, styrene-chlorostyrene monomers, and acrylic monomers such as Examples include acrylic acid ester monomers (methyl acrylate monomer, ethyl acrylate monomer, butyl acrylate, octyl acrylate monomer, phenyl acrylate monomer, 2-ethylhexyl acrylate monomer), etc.
Examples include methacrylic acid ester monomers (methyl methacrylate monomer, ethyl methacrylate monomer, butyl methacrylate monomer, phenyl methacrylate monomer).

The carrier core material (magnetic particles) used in the present invention includes, for example, surface-oxidized or unoxidized metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earths, and their alloys or oxides. Can be used. Moreover, there are no special restrictions on the manufacturing method.

The measurement method of the present invention will be described below.

(1) Frictional charge measurement: The measurement method will be explained in detail using FIG.

First, a mixture of a flow improver and a carrier whose weight ratio is 1:49 is poured into a metal measuring container 2 having a 500 mesh screen 3 at the bottom, and a mixture of 5O-100
Approximately 10~ in a 111f capacity polyethylene bottle
Shake by hand for 40 seconds, add about 0.5 to 145 g of the mixture, and cover with a metal lid 4. The weight of the entire measuring container 2 at this time is measured as L (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 lower, and the air volume control valve 6 is adjusted to set the pressure of the vacuum gauge 5 to 250 mmAq. This state is sufficient, preferably 2
Vacuum for 1 minute to remove the glidant. The potential of the electrometer 9 at this time is assumed to be (volts). Here, 8 is a capacitor whose capacity is C (gF). In addition, the weight of the entire measuring container after suction is weighed and defined as Wz (gl).The amount of frictional electrification (μc/g) of this fluidity improver is calculated as shown in the following formula.

(However, the measurement conditions are 23° C. and 60% RH.) Also, the carrier used for the measurement is EFV200/300 (manufactured by Powdertic Co., Ltd.).

[Example] The present invention will be described in detail below with reference to Examples and drawings. In addition, all % and parts indicate weight % and parts by weight.

Example 1 was sufficiently premixed using a Henschel mixer, melt-kneaded at least twice using a three-roll mill, and after cooling, coarsely ground to approximately 1 to 2 mm using a hammer mill, and then finely ground using an air jet type pulverizer. It was finely pulverized. Furthermore, the obtained finely pulverized product was classified and a particle size of 2 to 10 μm was selected so as to have the particle size distribution of the present invention, thereby obtaining colorant-containing resin particles.

Silica fine powder treated with 0.5 parts by weight of hexamethyldisilazane to 100 parts by weight of the above colorant-containing resin particles, triboelectric charge amount - 50 μc/g, BET specific surface area 230 m2/g
and 0.5 parts of alumina fine powder triboelectric charge amount of 1.7B/g,
A cyan toner was prepared by externally adding 7 g of BET specific surface area 100 m''.

This cyan toner Met.

To 5 parts of this cyan toner, a copolymer (number average molecular weight: 21,250,
weight average molecular weight 52360), weight average particle size 45μ,
35μ or less 4.2%, 35-40μ, 9.5%, 34μ
A Cu-Zn-Fe type ferrite carrier having a particle size distribution of 0.2% was coated with 0.5% of the carrier, and the carrier was mixed to a total of 100% to form a developer.

Using this developer, the development contrast was set to 270■ in a commercially available plain paper color copying machine (Color Laser Copier 500 manufactured by Canon), and the image was produced at 23°C/65%. High at 1.48 (it was clear with no fog at all. After that, I made io and oooo more copies, but the density drop during that time was as small as 0.05, and the fog and sharpness were the same as the initial one. was gotten.

In addition, when the development contrast was set to 330■ at low temperature and low humidity (20°C, 10% RH), the image density was as high as 1.47, and the present invention makes it possible to control the amount of charge under low humidity. This suggests that it was effective.

Further, when images were produced under high temperature and high humidity conditions (30° C./80%) with the development contrast set at 250×, a very stable and good image was obtained with an image density of 1.52.

Furthermore, 23℃/60%RH, 20℃/10%, 30℃/8
Even in the initial image after being left in each environment for 1 month at 0%,
No abnormalities were observed.

Comparative Example 1 In Example 1, image development was carried out in the same manner as in Example 1 except that the salt-forming compound I of the present invention was not used. %, about 250 V at 23°C/65%, and about 430 V at 20°C/10%, and the environmental stability was lower than in Example 1.

Comparative Example 2 Image development was carried out in the same manner as in Example 1 except that the alumina fine powder was not used. The initial image was as good as in Example 1, but at 20°C/10% Image density is 1.45 to 1.25 after 2000 sheets of continuous durability under
It declined to . When we took out the developer from inside the developing device, we found that it was in a very agglomerated state.
Liquidity was declining.

Example 2 Image formation was carried out in the same manner as in Example 1 except that the salt-forming compound (1) of the present invention was used, and good results were obtained.

Example 3 In Example 1, A#, 0. Instead, Ti0z has a surface area of 80 m''/g by the BET method and a charge amount of 110 gc/g with the magnetic particles used in the present invention.
The same procedure as in Example 1 was performed except that 0.4 part of fine powder was used, and good results were obtained.

Comparative Example 3 Image printing was carried out in the same manner as in Example 1 except that 10 parts by weight of salt-forming compound I was used, but the evaluation was discontinued due to severe toner scattering under high temperature and high humidity.

Example 4 Using the cyan toner of Example 1, a commercially available color copying machine (
Color laser copier 500. Images were produced by modifying a developing device (manufactured by Canon) to have the configuration shown in FIG. 2 with the following conditions set.

That is, in Fig. 2, 22 is a sleeve (coating layer thickness: 13 pm) coated with phenolic resin in which 40 parts by weight of molybdenum disulfide is dispersed on the surface of an aluminum cylinder.
It is. 24 is a urethane sponge roller. The developer applying blade 25 applies a linear pressure of 80 g/
It is in contact with cm. Further, the gap between the sleeve 22 and the latent image holder 21 was maintained at 250 μm, and the toner layer thickness was regulated at 50 parts m. All other conditions are set on the copier itself. 20℃/10%, 23℃/60%, 3
As a result of a durability test of 5,000 sheets under each environment of 0℃/80%, no sleeve contamination or sleeve fusion was observed in each environment, and the image density was stable at 1.40 to 1.55. A clear image with no fog was obtained.

[Effects of the Invention] As described above, according to the present invention, high quality and environmentally stable images can be obtained. Further, since the toner of the present invention has a fine particle size, the toner adheres faithfully to a minute electrostatic latent image, and a full-color image with high resolution and good color reproducibility can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a frictional charge measuring device, and FIG. 2 is a schematic diagram of a modified color copying machine used in the examples. l: Suction device 2: Measuring container 3: Conductive screen 4: Lid 5: Vacuum gauge 6: Air volume control valve 7; Suction port
8: Capacitor 9: Electrometer 21:
Latent image holding body 22 Sleeve 23: Developer 24
: Sponge roller 25 Niblade 26: Power supply

Claims (3)

[Claims] (1) An insulating non-magnetic color toner having at least non-magnetic colorant-containing polyester resin particles and a flow improver, wherein the non-magnetic colorant-containing polyester resin particles have a volume average diameter of 4 to 10 μm. , a binder resin whose main components are a diol component and a dicarboxylic acid component, and a salt-forming compound represented by the following formula ▲There are mathematical formulas, chemical formulas, tables, etc. ▼...(I), and the fluidity At least one of the improvers has an absolute value of electrification amount of 20μc/ when triboelectrified with the iron powder carrier.
A color toner characterized by having a weight of less than g. (2) The color toner has a volume average particle diameter of 6 to 10 μm, and contains 15 to 40 number % of toner particles of 5 μm or less, 1
0.1 to 5.0 volume% of 2.7 to 16.0 μm, 16 μm
Contains 1.0% by volume or less of m or more, 6.35 to 10.1
Toner particles with a particle size of μm are determined by the following formula: 9≦V×@d@v/N≦14 where V: % by volume of toner particles with a particle size of 6.35 to 10.1 μm N: 6.35 to 10. 2. The color toner according to claim 1, wherein the number % @d@v: of toner particles having a particle diameter of 1 μm satisfies the average volume diameter of all toner particles. (3) As a fluidity improver, the absolute value of the triboelectric charge amount with the carrier is 20 μc/g or less, and the specific surface area is 30 by BET method.
~200m^2/g of hydrophilic inorganic oxide and a negatively charged hydrophobic inorganic oxide with an absolute value of triboelectric charge amount of 50μc/g or more and a specific surface area of 80 to 300m^2/g by BET method 2. The color toner according to claim 1, wherein the color toner is added in an amount of 0.3 to 2% by weight based on the non-magnetic colorant-containing polyester resin particles.