JPH04177369A - Color developer - Google Patents

Abstract

PURPOSE:To stabilize the extent of chargeability in various surroundings as well as to secure a high quality image by containing a color toner with a specific external additive and a carrier with a specific addition component in a coat resin, respectively. CONSTITUTION:A carrier for a developer is one that has covered such resin as having a titanic compound containing carbon atoms 3-30 pieces with nitrogen one atom in the whole covering resin as far as 0.3-15wt.%, in organic resin containing a block polymer containing fluorine. In addition, a flow improver is a low tribo-impover having the absolute value of less than 30muc/g with the carrier. Accordingly, it is hard to be affected by surroundings such as temperature, humidity or the like, thus such an electrostatic charge developing color developer that has stable frictional chargeability at all times is securable.

Description

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

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 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. Furthermore, 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. No. 2,618,552. 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 described in Japanese Patent No. 3,909,258 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. As the thermoplastic resin, polystyrene resin is the most common, 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.

Also, if there is a step of transferring a toner image, usually
A step is provided to remove residual toner on the photoreceptor.

In recent years, there has been a rapid shift from monochrome copying to full-color copying in copying machines, etc., and two-color copying machines and full-color copying machines are being studied and put into practical use. 22.N
o, 1 (1983) and “Journal of Electrophotography Society J Vol.
25. There is also a report on the color reproducibility and gradation reproducibility of No. 1°P52 (1986).

However, unlike television, photographs, and color printed matter, they cannot be immediately 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 the toners are superimposed on the same support while adjusting the registration, a final full-color image is obtained by fixing twice.

In general, in the case of a so-called two-component development system in which the developer consists 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. Therefore, in order to obtain a good visible image, it is necessary that the toner has 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 even 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 a technique for adding a 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 additives on the surface of the toner particles, and the presence of additives that are not attached to the toner particles and become aggregates with each other, so-called free state. It is difficult to avoid. This tendency becomes more pronounced as the specific electrical resistance of the charging aid increases and as the particle size becomes finer. In such a case, the performance as a developer will be affected. For example, the amount of triboelectrification 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 auxiliary agent 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. In addition, even with toner obtained by such a method, the amount of triboelectric charge of the toner is unstable, and as mentioned above, it is not easy to obtain one that satisfies the developer characteristics. The reality is that products of sufficiently satisfactory quality are not available.

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 this 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. In addition, since the %FifE amount of 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 application of tribo to the replenished toner.

In addition, 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.

Many carriers have been studied from this point of view, but on the carrier side, for example, conductive carbon black or the like is added to the coating resin in order to eliminate carrier adhesion that occurs because the carrier itself is strongly charged. It has been proposed to disperse carbon black and coat it on a carrier, but so far it has not necessarily been possible to achieve a stable coating, and new problems such as fogging due to the release of carbon black etc. due to long-term use have arisen. is occurring.

Furthermore, examples have been proposed in which carriers are coated with fluorocarbon resins or silicone resins that have low surface energy, but carriers coated with resins that have low surface energy have poor adhesion to the carrier core material, and furthermore, the toner may be charged less. At present, there is still no satisfactory carrier because the start-up is slow, especially when original documents with a high image area ratio are continuously copied under high humidity.

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.

As a result of intensive studies on the charging stability of color developers, the present inventors discovered that friction it with carriers can be used as a fluidity improver.
It was confirmed that a low tribo flow improver having an absolute value of 30 μc/g or less can impart fluidity to toner without impairing the charging stability, and can improve development characteristics and transfer characteristics. I found it.

Previously, JP-A-60-136755 and JP-A-62
As in Japanese Patent No. 229158, examples of using low tribo additives such as titanium oxide have been proposed, but these are used in combination with so-called silica, and due to the characteristics of silica, the stability of charging is not necessarily fully satisfied. It was not something I could enjoy.

In addition, when the above-mentioned low tribo flow improver is used, especially when combined with a fluororesin-coated carrier with low surface free energy that is effective for extending life, the rise of charging will be further delayed, resulting in a color image like that of a color image. It has been found that when an original document with a high image area ratio is used, problems such as toner scattering occur.

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

That is, an object of the present invention is to provide a color developer for electrostatic charge development that is not easily influenced by environments such as temperature and humidity and has always stable triboelectric charging properties.

A further object of the present invention is to provide a color developer for electrostatic charge development that has clear image characteristics without fog and has excellent durability and stability.

Another object is to provide a color developer that is excellent in preventing carrier adhesion.

Another object is to provide a color developer with less toner scattering.

Another object is to provide a color developer that is less likely to cause toner to be spent on the surface of carrier particles and has a long life.

[Means and effects for solving the eight problems] The present invention is characterized by an insulating non-magnetic color toner containing at least colorant-containing resin particles and a flow improver, and a carrier core material of 0.1 In a developer containing a carrier having a weight average particle size of 10 to 100 μm and coated with ~5.0% by weight of an electrically insulating resin, 3 carbon atoms per 1 element
A carrier coated with a resin containing 0.3 to 15% by weight of a nitrogen-containing compound containing ~30 nitrogen-containing compounds based on the total coating resin; A color developer characterized in that it is a flow improver with a low triboelectricity having an absolute value.

Until now, as an example of using a compound containing a nitrogen atom as a coating material for a carrier, for example,
No. 124345, etc., proposes an example of a compound having an amine structure containing a tertiary amine as a charge control agent.

However, with the above carrier configuration, when the non-magnetic small particle size color toner of the present invention is combined with an insulating non-magnetic small particle size color toner that does not have a conductive member such as magnetic powder or carbon black, it is true that the initial characteristics are Although the results were good, it was found that the initial level could not always be maintained during continuous copying over a long period of time, and there were problems such as a decrease in image density and deterioration of fog.

Furthermore, an example of containing N-vinylcarbazoles has been proposed in JP-A-59-124346, etc.
The above example is just a carrier for positively chargeable toner, and is completely different from the present invention.

Furthermore, as a nitrogen-containing compound, it is possible to attach a quaternary ammonium salt to the carrier surface, for example, in JP-A No. 62-22
Although disclosed in Japanese Patent No. 9256, etc., the above proposal does not include the carrier particles in the resin, which is completely different from the present invention. The results were not satisfactory, as some cases of detachment occurred.

On the other hand, the use of a block copolymer containing fluorine as a coating material for a carrier is disclosed in Japanese Patent Application Laid-Open No. 57-9965.
Publication No. 2, JP-A-61-80161, JP-A-62
Although disclosed in Japanese Patent No. 39881 and the like, these fluorine-containing block polymers are significant in terms of stain resistance of the carrier surface. However, the fluctuations in the rise speed of IFN due to environmental differences, especially humidity fluctuations, are quite large.
When an original document with a high image area ratio is continuously copied under high humidity, charging is not sufficiently applied and toner scatters, which is unsatisfactory.

The reason why the carrier coated with the nitrogen-containing compound of the present invention in a fluorine-containing block polymer is extremely effective in stabilizing charging is because the fluorine-containing block polymer has a small surface energy. This is because the nitrogen-containing compound of the present invention compensates for the slowness in imparting charge to the toner. Furthermore, it has surprisingly been found that the nitrogen-containing compound of the present invention also plays a role in lowering the absolute triboelectric value especially under low humidity conditions. The reason for this is not yet clear, but it is presumed that the nitrogen-containing compound of the present invention acts as a leak site that causes the toner to charge up.

In the present invention, in order to make the above-mentioned charging rise function and leakage function sufficiently effective, the nitrogen-containing compound must have 3 to 30 carbon atoms, preferably 6 to 24 carbon atoms per nitrogen atom. It is necessary to contain

If the number of carbon atoms is less than 3, the moisture resistance properties, especially under high temperature and high humidity conditions, will deteriorate, and problems such as toner scattering due to triboelectric deterioration will occur.

In addition, if the number of carbon atoms is more than 30, the characteristics at high temperatures will be improved and the charging rise will be good, but the leakage function will be reduced, resulting in problems such as a decrease in image density due to increased triboelectricity at low temperatures and low humidity. will occur.

As the nitrogen-containing compound used in the present invention, general compounds such as a compound having an amine structure and a compound having a pyridine ring structure can be used.

Particularly preferred compounds for the present invention are compounds having an amine structure, and are represented by I below.

The block copolymer used as the coating resin for the carrier surface of the present invention can be divided into a main segment and a subordinate segment that share functions.

The ratio of main segment to total block copolymer is 51
% to 95%, preferably 55 to 90%. More preferably, it is 60 to 80%.

As the main segment, styrene, acrylic ester, methacrylic ester, etc. can be used alone or in combination of two or more. For example, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polystyrene, chloropolystyrene,
Poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer , styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, styrene-α-methyl chloroacrylate copolymer, etc. can give.

Examples of the secondary segment include homopolymers or copolymers consisting of at least one polymer selected from tetrafluoroethylene, vinylidene fluoride, vinyl fluoride, trifluorochloroethylene, dichlorodifluoroethylene, etc. .

In the present invention, the above-mentioned fluorine-containing block polymer and other resins may be blended and used.

For example, styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p
-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p- methoxystyrene,
p-chlorostyrene, 3,4-dichlorostyrene, m-
Styrene derivatives such as nitrostyrene, 0-nitrostyrene, and p-nitrostyrene; ethylene and unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; unsaturated diolefins such as butadiene and isoprene; vinyl chloride; Vinyl halides such as vinylidene chloride and vinyl bromide; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate: methacrylic acid and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, α-methylene aliphatic monocarboxylic acid esters such as isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, conyaacrylate, methyl acrylate, acrylic Ethyl acid, n-butyl acrylate, isobutyl acrylate,
Acrylic acid esters such as propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate: maleic acid, maleic acid half ester: vinyl methyl ether,
Vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; Vinyl naphthalenes; Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; Acrolein Polymerized products using one or more of the following are used.

Acrylic resins such as styrene-methacrylate copolymers and styrene-acrylate copolymers are preferred because they have excellent durability and long service life.

The average molecular weight of the above copolymer is determined to be a number average molecular weight of 10.
00-100,000, preferably 17,000-75
,000, weight average molecular weight is 25,000 to 300,0
00. It is preferably 49,000 to 150,000.

If the average molecular weight is smaller than the above range, the adhesion with the surface of the carrier core material will improve, but the carrier particles will tend to coalesce (at the same time, toner spent will tend to occur and charging will become non-uniform.On the other hand, if the average molecular weight If it is larger than the above range, the coating strength increases, but cracks are likely to occur in the coating resin due to impact (not only this, but also the coating properties become unstable).

In particular, the material of the magnetic particles used in the present invention is 9
8% or more Cu-Zn-Fe (metal composition ratio (5-20)
Ferrite particles having a composition of + (5 to 20) : (30 to 80) are preferred in order to easily make the surface uniform and to stabilize the charging ability.

As the fluid improver used in the present invention, the above-mentioned 1! :
Any material may be used as long as it satisfies the electrical properties.

For example, inorganic oxides such as silica, alumina, titanium oxide, zirconium oxide, boron nitride, and silicon carbide may be used as they are or may be surface-treated to a desired amount of charge.

Suitable for the present invention are titanium oxide and alumina, which can relatively easily obtain a sharp particle size distribution, and particularly suitable is titanium oxide, which has the same polarity as the toner.

Although there are no particular restrictions on its manufacturing method or crystal structure, titanium oxide manufactured from titanium alkoxide by a gas phase method at 600° C. or lower is particularly suitable because it has a sharp particle size distribution and high sphericity.

Specific examples of the titanium alkoxide include titanium tetramethoxide, titanium tetraethoxide, titanium tetrapropoxide, titanium tetrabutoxide, and jetoxytitanium oxide.

In particular, in the present invention, as an additive, an average particle size of 20
~200mμ, preferably 20-150mμ and 300~
Specific electrical resistance 106~ with two peaks at 800 mμ
It is even more effective to externally add positively chargeable organic resin particles having a resistance of 1014 Ωm.

The reason for this is that the charge-up caused by excessive rubbing between the binder resin and the carrier used in the present invention is further neutralized by the organic resin particles.

Furthermore, by adding the organic resin particles, the rise in charging of the toner is further promoted, and extremely stable charging characteristics are achieved from the initial stage.

The number of particles constituting the resin particles used in the present invention is not particularly limited, but must be selected in consideration of the amount of charge of the toner, etc. Specific examples of monomers having addition polymerizability that can be used in the present invention include the following:
can be mentioned.

That is, styrene and its derivatives, such as alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, fluorostyrene, chlorostyrene. , bromostyrene, dipromostyrene, halogenated styrene such as iodostyrene, and nitrostyrene, acetylstyrene, methoxystyrene and the like.

Additionally, addition-polymerizable unsaturated carboxylic acids, namely acrylic acid, methacrylic acid, α-ethyl acrylic acid, crotonic acid,
Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as α-methylcrotonic acid, α-ethylcrotonic acid, isocrotonic acid, tiglic acid, and ungellic acid, or maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and glutaconic acid. addition-polymerizable unsaturated aliphatic dicarboxylic acids such as dihydromuconic acid and dihydromuconic acid.

Furthermore, metal salts of these carboxylic acids can also be used, and this metal salt formation can be carried out after the completion of polymerization.

Further, examples thereof include esterified products of the above-mentioned addition polymerizable unsaturated carboxylic acid and alcohols such as alkyl alcohols, halogenated alkyl alcohols, alkoxyalkyl alcohols, aralkyl alcohols, and alkenyl alcohols. Specific examples of the above alcohol include methyl alcohol, ethyl alcohol, propyl alcohol,
Alkyl alcohols such as butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol: Halogenated alkyl alcohols that are further halogenated from these alkyl alcohols: methoxyethyl alcohol, Alkoxyalkyl alcohols such as ethoxyethyl alcohol, ethoxyshethoxydiethyl alcohol, methoxypropyl alcohol, and ethoxypropyl alcohol; aralkyl alcohols such as benzyl alcohol, phenylethyl alcohol, and phenylpropyl alcohol; alkenyl alcohols such as allyl alcohol and crotonyl alcohol. It will be done.

Also, amides and nitriles derived from the addition-polymerizable unsaturated carboxylic acids; ethylene, propylene, butene,
Aliphatic monoolefins such as isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2-dichloroethylene, 1,2-dibromoethylene, 1,2-short ethylene, isopropenyl chloride, isopropenyl bromide , allyl chloride, allyl bromide, vinylidene chloride, vinyl fluoride, vinylidene fluoride; 1.
3-butadiene, 1,3-pentadiene, 2-methyl-
1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 3-methyl-2,4-
Examples include conjugated diene aliphatic diolefins such as hexadiene.

Further examples include vinyl acetate, vinyl ethers; nitrogen-containing vinyl compounds such as vinyl carbazole, vinyl pyridine, and vinyl pyrrolidone.

The fine powder according to the present invention may be obtained by polymerizing one or more of these mercury.

The resin particles used in the present invention are not limited to using only one type, but multiple types can be used in combination.

Furthermore, the resin particles used in the present invention can be produced by any method that can produce spherical fine particles, such as spray drying, suspension polymerization, emulsion polymerization, soap-free polymerization, seed polymerization, and mechanical pulverization. It can also be used in methods. Among these, a soap-free polymerization method is particularly suitable, as there is no residual emulsifier, so it does not inhibit the chargeability of the toner and has little environmental variation in specific electrical resistance, but is not particularly limited.

In order to make the resin particles used in the present invention have two peaks, two types of particles may be dry-blended or wet-blended and then dried. However, it is preferable to convert the emulsion state after polymerization into a mixture of primary particles during drying. It is more preferable to achieve two peaks. Further, heat treatment or crushing treatment may be performed as necessary.

The resin particles may be subjected to particle surface treatment if necessary. Examples of surface treatment methods include iron, nickel, cobalt,
A method of surface treatment of metals such as copper, zinc, gold, and silver by vapor deposition or plating, or fixation of the above metals, magnetic materials, metal oxides such as conductive zinc oxide, etc. by ion adsorption or external addition. Alternatively, a triboelectrically chargeable organic compound such as a pigment or dye, or even a polymer resin may be supported by coating or external addition.

Further, the molecular weight distribution of the resin particles used in the present invention needs to have a peak molecular weight in the range of 10,000 to 5,000,000, preferably in the range of 20,000 to 1,000,000. If the peak molecular weight is larger than 5 million, it will have an adverse effect on the fixing properties of the color toner, and if it is smaller than 10,000, the magnetic particles will be contaminated or the blocking resistance will deteriorate.

As the binding substance used in the colorant-containing resin particles of the present invention, various resin materials conventionally known as toner binding resins for electrophotography are used.

For example, styrene copolymers such as polystyrene, styrene/butadiene copolymer, styrene/acrylic copolymer, ethylene copolymers such as polyethylene, ethylene/vinyl acetate copolymer, and ethylene/vinyl alcohol copolymer. , phenolic resin, epoxy resin, acrylic phthalate resin, polyamide resin, polyester resin,
Maleic acid resin, etc. Furthermore, there are no particular restrictions on the manufacturing method of any of the resins.

Among these resins, the effect of the present invention is particularly great when a polyester resin having a high negative charging ability is used. That is, although polyester resin has excellent fixing properties and is suitable for color toner, it has a strong negative charging ability and tends to be overcharged. However, when polyester resin is used in the structure of the present invention, the disadvantages are improved and an excellent Toner is obtained.

In particular, the following formula (wherein 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 a diol component, and a carboxylic acid component consisting of a bivalent or higher carboxylic acid, its acid anhydride, or its lower alkyl ester (e.g., fumaric acid, maleic acid, maleic anhydride). A polyester resin obtained by cocondensation polymerization with phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) is more preferable because it has sharp melting characteristics.

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. In the present invention, the present invention becomes even more effective when a negatively charged developer is used, and the negative charge control agent at that time may be, for example, a metal complex of alkyl-substituted salicylic acid (for example, Z-T).
Examples include organometallic complexes such as chromium complexes or zinc complexes of ert-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 preparing a two-component developer by mixing with the toner according to the present invention, the mixing ratio is 2 as the toner concentration in the developer.
．． Good results are usually obtained between 0% and 12% by weight, preferably between 3% and 9%. Toner density is 2
．． If it is more than 0%, the image density is too low to be practical, and 12%
This increases fogging and in-machine scattering, and shortens the useful life of the developer.

As the colorant used in the present invention, a wide variety of known dyes and pigments can be used, such as phthalocyanine blue, industhrene blue, peacock blue, permanent red, lake red, rhodamine lake, banza yellow, permanent yellow, benzidine yellow, etc. . Its content is preferably 0.5 to 9% by weight.

In producing the toner of the present invention, the constituent materials are thoroughly kneaded using a thermal kneading machine such as a hot roll, kneader, or extruder, and then obtained by mechanical crushing and classification, or by adding color to the binder resin solution. After dispersing materials such as agents,
There are various methods such as spray drying, or polymerization toner manufacturing method, which obtains a toner by mixing a specified material with monomers that constitute the binder resin and then polymerizing this emulsified suspension. Can be applied.

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

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

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

FIG. 1 is an explanatory diagram of an apparatus for measuring the amount of triboelectric charge of toner. First, 50 g of a mixture of toner and carrier whose weight ratio is 1:19, whose triboelectric charge amount is to be measured, is placed in a metal measuring container 22 with a 500-mesh screen 23 at the bottom.
The mixture is placed in a polyethylene bottle having a capacity of 50 to 100 mA, shaken by hand 30 times and 500 times, and approximately 0.5 to 0.9 g of the mixture (developer) is added thereto, and a metal lid 24 is placed on the bottle.

The weight of the entire measuring container 22 at this time is measured as W+(g). Next, in the suction device 21 (at least the part in contact with the measurement container 22 is an insulator), suction is performed from the suction port 27, and the air volume control valve 26 is adjusted to adjust the pressure of the vacuum gauge 25 to 250 mm.
Let it be Aq.

In this state, suction is applied for a sufficient period, preferably about 2 minutes, to remove the toner. The potential of the electrometer 29 at this time is assumed to be ■ (volt). Here, 28 is a capacitor, and the capacitance is C (μF). In addition, the amount of triboelectric charge (μ
c/g) is calculated as shown below.

[Examples] The present invention will be described in detail below with reference to Examples and drawings. All percentages and parts are by weight.

was dissolved in a xylene/methyl ethyl ketone mixed solvent to obtain a weight average particle size of 45 μm and 135 μm or less, 4.2%, 35 to 4
0.5% to Cu-Zn-Fe-based ferrite carrier with particle size distribution of 0 μm, 9.5%, 34 μm or more and 0.2%.
% coated carrier was prepared.

On the other hand, the mixture was slightly mixed with a Henschel mixer, melt-kneaded with a twin-screw ratio kneader, and after cooling, coarsely pulverized with a hammer mill to approximately 1 to 2 mm, and then finely pulverized with an air jet method. It was finely ground. Furthermore, the obtained finely pulverized product is classified to have the particle size distribution of the present invention.
~10 μm was selected to obtain colorant synthetic resin particles.

0.7 parts of titanium oxide with a BET of 120 m2/g obtained by gas-phase decomposition of titanium tetraisopropoxide with a charge of -3.6 μc/g at 350 t, an average particle size of 55 mμ, and 1 charge +9゜μc on the above resin particles. /g of styrene/methyl methacrylate resin particles were combined to prepare a cyan toner.

N/L of this cyan toner and carrier (20℃/10
%), N/N (23℃/60%), H/H (30℃/
Table 1 shows the amount of charge under 80%).

Next, a commercially available color copying machine CLC using the above developer and toner and with the development contrast fixed at 300V was used.
-500 (manufactured by Canon) and an original document with an image area ratio of 50%, the above N/L, N/N%H7
When I made 20,000 speed-read copies under H, the image density was high and the image was clear with no fog. Display the results -
From Table 1 shown in Table 1, it can be seen that the above-mentioned developer exhibits small fluctuations due to environmental changes and is very good.

The following Examples and Comparative Examples are also shown in Table 1.

In Example 1 on JUI, image formation was carried out in the same manner as in Example 1 except that no tertiary amine was used, and the image density decreased to 1.25 under N/L.

In Example 1, titanium oxide was used, except that silicic acid fine powder (BET 170 m2/g, charge amount -7.5 μc/g) that had been hydrophobized with dimethyldichlorosilane was used. When image printing was carried out in the same manner as in Example 1, the image density decreased to 1.15 at 20° C./10%.

Comparative Example 3 When image printing was performed in the same manner as in Example 1 except that titanium oxide was not used, the initial results were good, but after about 500 sheets, toner scattering was severe and evaluation was discontinued. .

cold] 1 liter In Example 1, styrene-methyl methacrylate-tetrafluoroethylene-vinylidene fluoride (40:40
:15:5) was imaged in the same manner as in Example 1 except for using a block polymer photopolymerized.
Similar to Example 1, good results were obtained.

Ratio: 18M
10,000 copies were good, but when printing up to 20,000 copies, some toner scattering was observed compared to Example 1, especially under H/H, but there was no major problem on actual images.

For reference, an original document with an image area ratio of 25% was used to print out the image, and no toner scattering was observed.

In Example 1, Hinatsuritan produced titanium oxide (BET), which was hydrophobicized with a titanium coupling agent to a degree of hydrophobicity of 50%.
Good results were obtained when image formation was carried out in the same manner as in Example 1 except that a charge of 90 m2/g and a charge amount of -12 .mu.c/g was used.

(The following is a blank space) C Effects of the Invention The present invention provides stabilization of chargeability in various environments using a color developer containing a color toner having a specific external additive and a carrier having a specific additive component in the coating resin. image quality and obtain high-quality images.

[Brief explanation of the drawing]

′! Figure J1' is an explanatory diagram of an apparatus for measuring the amount of triboelectric charge of toner.

Claims (4)

[Claims] (1) Weight average particle size of an insulating non-magnetic color toner containing at least a colorant-containing resin particle and a flow improver and coated with an electrically insulating resin of 0.1 to 5.0% by weight based on the weight of the carrier core material. A color developer comprising a carrier having a diameter of 10 to 100 μm, [1] The carrier contains 3 to 30 carbon atoms per nitrogen atom in an organic resin containing a fluorine-containing block polymer. A carrier coated with a resin containing a nitrogen-containing compound in an amount of 0.3 to 15% by weight based on the total coating resin, [2] The fluidity improver is added to the carrier in an amount of 30 μc/
A color developer characterized in that it is a low tribo flow improver having an absolute value of g or less. (2) The color developer according to claim 1, wherein the fluidity improver is titanium oxide or alumina. (3) The color developer according to claim 1, wherein the fluidity improver is titanium oxide that is charged to the same polarity as the toner. (4) The flow improver is made of titanium alkoxide.
The color developer according to claim 1, wherein the color developer is an amorphous spherical titanium oxide obtained by a gas phase pyrolysis reaction at a temperature of 0° C. or lower and charged to the same polarity as the toner.