JPH0778648B2 - Full color toner kit and developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a full-color electrophotographic toner kit, and in particular, using yellow, magenta, cyan, and black toners, a clear and wide range of color tone and high-definition color copy can be obtained. The present invention relates to a full color toner kit and a developer.

[Conventional technology]

In recent years, the development from mono-color copying to full-color copying is rapidly progressing in copying machines and the like, and two-color copying machines and full-color copying machines are being studied and put into practical use. For example, there are reports of color reproducibility and gradation reproducibility such as "Electrophotographic Society Journal" Vol22, No.1 (1983) and "Electrophotographic Society Journal" Vol25, No.1, P52 (1986).

However, it is not immediately contrasted with the real thing like TV, photographs and color prints, and for those who can see color images that are more beautifully processed than the real ones, the full-color electrophotographic images currently in practical use are not always necessary. It is not satisfactory.

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

In the method, first, light from a document is formed on a photoconductive layer through a color separation light transmitting filter having a complementary color relationship with a color of a toner. Next, the toner is held on the support through the developing and transfer steps. Next, the above-mentioned steps are sequentially carried out a plurality of times, and the final full-color image is obtained by superposing the toners on the same support while fixing the resists and fixing the toners once.

The developing method used at this time is U.S. Pat. No. 2,618,55.
The cascade developing method described in US Pat. No. 2, the magnetic brush method described in US Pat. No. 2,874,063, and the touchdown method are also available.

Of these, the most widely used method is the magnetic brush method. In this method, magnetic particles such as steel and ferrite are used as carriers. The developer consisting of toner and magnetic carrier is held by a magnet, and the magnetic field of the magnet causes the developer to be arranged in a brush shape. When this magnetic brush contacts the electrostatic latent image surface on the photoconductive layer, toner is attracted from the brush to the electrostatic latent image for development.

However, in this method, the developing efficiency is extremely low because the ratio of the consumable toner in the magnetic brush in the developing section is small. For example, only 1 to 5% of the total developer may be used. If a large amount of developer is used to improve the developing efficiency, the developing device becomes large and heavy, which is not suitable for making the copying machine compact and lightweight.

In particular, a full-color copying machine requires at least three developing devices, so it is not desirable to make the full-color copying machine compact.

In terms of image quality, traces of rubbing by a magnetic brush are generated in the developed image like sweeps, and strong mixing of toner and carrier inside the developing unit causes charge deterioration and toner adheres to non-image areas. It has problems such as easy occurrence.

In color electrophotography, which requires development of a plurality of times and superposition of several toner layers of different colors on the same support, the following items are necessary and sufficient conditions for the color toners to have: Can be mentioned.

(1) The fixed toner needs to be in a state of almost complete melting such that the shape of the toner particles cannot be discriminated so as not to diffusely reflect light and prevent color reproduction. .

(2) It must be a colored toner having transparency that does not interfere with the 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.

The electrophotographic characteristics of the toner include the following items.

(4) It is necessary to have good charging characteristics with little environmental dependence.

(5) It is necessary that the replenishment from the hopper to the developing device can be smoothly performed and that the carrier and the residual developer can be easily mixed with each other so that they can be easily mixed with each other.

(6) The toner must have good storage stability without caking or cohesion during handling or storage.

(7) In the cleaning process for removing the residual toner on the photoconductor, the toner must not adhere to the photoconductor or cause cleaning failure.

However, at present, there is no color toner kit that satisfies the above performances.

For example, as disclosed in JP-A-59-26757, a color toner kit comprising three types of toners of three primary colors is used as a full-color toner.

However, while these combinations are relatively balanced for tone reproduction, their electrophotographic properties are:
There are still points to be improved in charging properties other than storage stability and durability in repeated copying.

Further, the above-mentioned proposal obtains a black color by superimposing toners of three colors. Therefore, the subtle difference of these three colors and the difference of superimposition at the time of development-transfer-fixing are reflected in the black color tone, The complexity of color matching of each color toner in the manufacturing process and the development-transfer process and fixing process of the copying process must be highly accurate, which naturally complicates the process and causes a cost increase.

Also, there are many applications for monochromatic color toners such as JP-A-53-68234 and U.S. Pat. No. 4,518,672, but at least three full color toners, preferably four color toners, are well balanced in color balance. There is no point in discussing color reproducibility and electrophotographic characteristics of only one color.

In principle, if there are three primary colors, yellow, magenta, and cyan, it should be possible to reproduce almost all colors by the subtractive color mixing method, and therefore full-color copying machines currently on the market. Is configured to use color toners of three primary colors in an overlapping manner. This should ideally be able to achieve all colors in all density ranges, but in reality, it still improves the spectral reflectance characteristics of toner, the color mixing properties of toner when superposed, and the decrease in saturation due to subtractive color mixing. Have a point.

Obtaining a black color by superimposing three colors requires more difficulty as described above. In selecting the colorant that determines the color tone of these color toners, the hue of the toner in the above 6 items,
When the emphasis is placed on spectral reflection characteristics and color reproduction, electrophotographic characteristics cannot be sufficiently imparted, and there are problems with respect to charging characteristics, durability characteristics due to repeated copying, toner transportability, and storage characteristics. When the electrophotographic characteristics as described above are emphasized, it is unavoidable to select a coloring agent having a bad tint. That is, it is extremely difficult to satisfy both color reproducibility and electrophotographic characteristics.

Furthermore, recently, a digital color copier that forms a latent image on a photoconductor using a laser beam has been put into practical use.
Since it was not possible to faithfully reproduce the laser spot on the photoconductor with the conventional toner, it was difficult to obtain a high-definition copy.

[Object of the Invention]

The inventors of the present invention have conducted extensive studies to improve these problems, and have a wide range of color reproducibility and have a wide range of color reproducibility by using a black toner newly for black ink addition in addition to the three primary color toners. In particular, the present invention has reached a full-color toner kit exhibiting particularly preferable characteristics.

An object of the present invention is to provide a full-color toner kit having preferable spectral reflection characteristics.

Another object of the present invention is to provide a full-color toner kit which exhibits good color mixture and fixability in four-color toner kits of yellow, magenta, cyan and black, and which can obtain a wide range of color tone reproducibility.

Another object is to provide a full-color toner kit having sufficient triboelectric charge characteristics.

Another object is to provide a full-color toner kit having good transportability.

Yet another object is to provide a full color toner kit that is clean.

Another object is to provide a full-color toner kit with less scattering.

Another object is to provide a full-color toner kit with high gloss that significantly enhances image quality.

Another object of the present invention is to provide a full-color toner kit which has excellent durability and is hard to spend on the carrier even after repeated copying.

Another object is to provide a full-color toner kit that does not cause toner sticking on the photoconductor or cleaning failure.

Another object is to provide a full-color toner kit that faithfully reproduces the latent image on the drum and enables high-definition color copying.

[Outline of Invention]

The feature is that at least yellow toner,
A full-color toner kit for multicolor electrophotography having a magenta toner, a cyan toner and a black toner, wherein the yellow toner has yellow colorant-containing resin particles and two or more types of fluidity improvers, and the particle size distribution thereof is a volume average. 40% of particle size is 6.0 to 10.0μ and number average distribution is 5.04μ or less
Below, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to
1.5 g / cm ³ , and the apparent viscosity of the yellow toner at 100 ° C. and 90 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5
Within the range of × 10 ⁶ poise, DSC endothermic peak value is 58 to 72
C., the gloss is 5.0% or more, the yellow colorant is contained 0.1 to 12.0 parts by weight with respect to 100 parts by weight of the binder resin, the chromaticity of the yellow toner is a ^* -6.5 to -26.5, b ^* 73.0-93.0
And L ^* 77.0 to 97.0, having 250 or more mesh carrier particles of 65% by weight or more and 400 or less mesh particles of 20% or less by weight, and having a triboelectric property of -10 to styrene resin coated ferrite carrier. −
50 μc / g, the magenta toner contains magenta colorant-containing resin particles and two or more types of fluidity improvers, and the particle size distribution is volume average particle size 6.0 to 10.0 μ and number average distribution 5.04 μ or less. Is 40
% Or less, 12.7 μ or more of the volume average distribution is 10% or less,
Liquidity index of 5% to 25%, apparent density of 0.2
~ 1.5 g / cm ³ , 100 ° C and 900 ° C of the magenta toner
Apparent viscosity in 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ⁴ to
It is in the range of 5 × 10 ⁶ poise and the endothermic peak value of DSC is 58〜.
The temperature is 72 ° C, the glossiness is 5.0% or more, and the magenta colorant is contained in 0.1 to 15.0 parts by weight with respect to 100 parts by weight of the binder resin.
The chromaticity of the magenta toner is a ^* 60.0 to 80.0, b ^* -12.0 to −3.
2.0 and L ^* 40.0 to 60.0, 250 mesh, 350 mesh particles of 65% by weight or more of carrier particles, 400 mesh is 20% by weight or less styrene-based resin coated ferritic carrier triboelectric charge characteristics -10 ~ −
50 μc / g, the cyan toner contains cyan colorant-containing resin particles and two or more types of fluidity improvers, and the particle size distribution thereof is a volume average particle size of 6.0 to 10.0 μ and a number average distribution of 5.04 μ or less. Is 40% or less, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to 1.5.
g / cm ³ , the apparent viscosity of the cyan toner at 100 ° C. and 90 ° C. is in the range of 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5 × 10 ⁶ poise, and the endothermic peak value of DSC is 58 to 72 ° C., gloss of 5.0% or more, and 0.1 to 15.0 parts by weight of a cyan colorant with respect to 100 parts by weight of a binder resin, and the chromaticity of the cyan toner is a ^* −8 to −28.0. , b ^* −30.0 to −50.0 and L ^* 3
9.0-59.0, 250 mesh, 350 mesh particles 65 wt% or more of the carrier particles, 400 mesh is 20 wt% or less styrene resin coat Ferrite carrier triboelectric charge characteristics to -10 ~ -50μc / g The black toner is resin particles containing carbon black,
It contains a fluidity improver and a friction reducing agent, and its particle size distribution is volume average particle size of 6.0 to 10.0μ, number average distribution of 5.04μ or less is 40% or less, and volume average distribution of 12.7μ or more is 10% or less. , The liquidity index is 5% or more and 25% or less, and the apparent density
0.2 to 1.5 g / cm ³ , and the apparent viscosity of the toner at 100 ° C. and 90 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5 × 10 ⁶
It is in the range of poise, the endothermic peak value of DSC is 58 to 72 ° C, and the carbon black is 0.1 to 100 parts by weight of the binder resin.
~ 10.0 parts by weight, the chromaticity of the black toner is a ^* -2.0 ~
Friction against styrenic resin coated ferrite carriers having 3.0, b ^* −1.0 to 3.0 and L ^* 26.0 to 45.0, having 65 or more wt% carrier particles of 250 mesh pass or 350 mesh pass and 400 wt% or less of 400 mesh pass. A full-color toner kit characterized in that the toner has a charge amount characteristic of −10 to −50 μc / g.

A further object of the present invention is to provide a two-component type developer having each color toner used in the above full-color toner kit and a resin-coated ferrite carrier.

[Specific Description of the Invention]

An example of a full-color electronic copying machine to which the color electrophotographic method according to the present invention is applied will be described with reference to FIG.

The electrostatic latent image formed on the photosensitive drum 1 by an appropriate means is visualized by the developer in the developing device 2-1 attached to the developing unit 2 which reciprocates in the direction of the arrow. This developing toner is transferred by the transfer charger 8 onto the transfer material held by the electrostatic charging device 7 on the transfer drum 6 by electrostatic attraction.

Next, as the second color, the developing unit moves and the developing unit 2-2
Faces the photosensitive drum 1. Then, the toner image is developed by the developer in the developing device 2-2, and this toner image is also transferred onto the same transfer material as described above.

Further, the third and fourth colors are similarly processed. In this manner, the transfer drum 6 is rotated by a predetermined number while holding the transfer material, and images of a predetermined number of colors are transferred in multiple. The multiple-transferred transfer material is separated from the transfer drum 6 by the separation charging device 9 and passes through the fixing device 10 to form a final full-color copy image.

Further, the replenishment toner supplied to the developing devices 2-1 to 2-4 is supplied from the replenishment hopper 3 provided for each color to the developing device 2-1 through the toner conveying cable 4 in a fixed amount based on the replenishment signal. It is replenished when the developing machine arrives at the developing position in the transport screen (16 in FIG. 2). This replenishment toner is uniformly mixed with the developer in the developing device in advance in the developing device by the mixing-conveying screws 16 and 17 shown in FIG. 2 so as to have a predetermined developer concentration.

At this time, the mixing ratio of the carrier and the toner is an extremely important factor from the viewpoint of the developing effect.

That is, the developer adhering to the surface of the sleeve containing the magnet rubs the electrostatic latent image to make the latent image visible with toner. As a result, the toner is gradually consumed from the developer, the ratio of the toner to the carrier decreases, that is, the density of the developer decreases, and the density of the developed image gradually decreases. Therefore, the toner is appropriately replenished, but in this case, if the toner is replenished more than appropriate amount, the density of the image becomes too high and fog increases. Therefore, it is necessary to accurately detect the density of the developer in order to continuously obtain images of a desired color tone.

As a method of detecting the developer concentration, there is a method of detecting the reflection or transmission density of the developer in the infrared region as described in JP-A-53-107853. According to this method, the change of the reflectance depending on the developer concentration, that is, the change of the reflected light amount can be made large, so that not only the detection accuracy can be improved but also the color copy can be used in addition to the black and white copy. However, this method reflects the toner in the infrared region,
Or, because it detects transmitted light, it is not possible to use carbon black, iron black, nigrosine dye, etc., which are widely used as black colorants in the past, and it is necessary to use colorants that reflect or transmit in the infrared region. There was a big problem that it had to be done.

As a method for solving this, Japanese Patent Application Laid-Open No. 48-63727,
As disclosed in JP-A-57-11936, two or more kinds of coloring agents such as dyes and pigments that reflect or transmit infrared light and are not black are appropriately mixed with a binder resin and mixed and kneaded. There is a means of using a blackened toner. It is possible to obtain a substantially black toner by combining a coloring material that is not black.

However, the use of two or more colorants is difficult to disperse in the binder resin, and the cost is higher than that of a toner using a carbon black which is not completely black and is slightly colored. occured.

In addition, as a method of detecting the developer concentration, there is a method of detecting the developer concentration by performing development on the photoconductor once and measuring the concentration. This method has the advantage that the copy density is stable because the actual development is performed and the measurement is performed. Further, it is possible to use carbon black or the like for the black toner. However, the use of this method with four colors has the drawback that the development process of the copier becomes very complicated.

In order to solve the above problems, yellow, magenta,
Each cyan toner uses a method that detects the reflection or transmission density of the developer in the infrared region, and black toner uses the method that develops once on the photoconductor and then measures the density. A method of detecting the concentration has been proposed. That is, the above-mentioned detection method can be realized by using the color toner kit of the present invention.

That is, each of the yellow, magenta, and cyan toners has a sufficient spectral reflectance in the near infrared region, and by using the carbon black for the black toner, it is possible to achieve complete blackness at low cost. it can.

The yellow, magenta, and cyan toners each preferably have a spectral reflectance of 40% or more in the near infrared region, particularly in the range of 900 to 1000 nm, more preferably 60% or more, and particularly preferably 70% or more.

Theoretically, the difference between the spectral reflectances of the toner and the carrier should be small, but if it is 40% or less, the detection capability of the detection device, that is, the spectral transmittance of the fiber, the spectral transmittance of the dichroic mirror. , S / of electrical signal processing circuit
The total power of factors that determine the detection accuracy, such as the N ratio and the assembly tolerance of the detection device, becomes less than the limit, and the carrier and toner cannot be stably discriminated, and the developer concentration cannot be quantitatively determined.

The fluidity index, which has a close effect on the toner transportability and the mixing property with the carrier, is preferably 5% or more and 25% or less.

The fluidity index is one of the indicators of fluidity. The higher the value, the poorer the fluidity. If the value is too low, the fluidity is too good, and the toner scattering in the apparatus tends to occur.

FIG. 2 shows an example of a replenishment-development system using the full-color toner kit of the present invention. Conveyance-mixing screws 16 and 17
When the replenishment toner and the developer already in the developing device are uniformly mixed via the, if the fluidity index is 25% or more, the mixing property with the developer, that is, some toner is already left on the carrier surface. The mixability of the replenished toner into the electrically-adhered particle aggregates deteriorates, and as a result, it becomes impossible to achieve a constant and uniform developer concentration in a short time. High and low occur.

This causes the developing sleeve to have a weaker developing ability, which causes uneven development with respect to the same latent image potential, resulting in problems such as partial fog and uneven density in image quality.

On the other hand, if the fluidity index is 5% or less, during development, scattering of the developing sleeve 12 from the inside of the machine is promoted, which causes contamination of the wire of the charging corotron. Further, the fluidity is so good that the toner easily passes through the toner transport cable 4 in a jet state and overflows at the toner supply port 5.

Toner replenishment from the replenishment hopper 3 to the developing device 2 is performed by rotating the supply screen 13 in the toner carrying cable 4 for a predetermined time in accordance with the signal from the developer concentration detector. Is 0.2 or less, the retention of the toner in the supply screen 16 becomes insufficient, and even if the screen rotates for a certain time, a larger amount of toner than the required amount is supplied into the developing device.

If it is 1.5 or more, the toner stays too much in the screw 13, and the supply screw is disconnected due to the clogging of the toner conveying cable and the overload caused by the clogging. Therefore, the preferable range of the apparent density is 0.25 to 1.0, and more preferably 0.3 to
0.8.

As means for achieving the fluidity index and the apparent density of the present invention, the binder resin particles having preferable fluidity, the type of the fluidity improver described in the specification of the present invention, the addition amount, the present invention The particle size distribution of the color toner, further the amount of the contained colorant transferred to the surface of the resin particles and exposed, in other words, the compatibility of the colorant with the binder resin,
It can be obtained by selecting and controlling the type of colorant.

As the particle size distribution of the full-color toner kit used in the present invention, the volume average diameter is 6.0 μ to 10.0 μ, preferably 7.0 μ.
~ 9.5μ, more preferably 7.5μ ~ 9.0μ, 5.04μ or less of the number average distribution is 40% or less, preferably 30% or less,
More preferably 25% or less, the volume average distribution of 12.7μ
The above is 10% or less, preferably 7% or less, and more preferably 5% or less.

By reducing the particle size of the toner as described above, it is possible to faithfully reproduce the laser spot on the photoconductor in the digital color copying machine, and it is possible to obtain a much finer color copy than before.

Volume average diameter of 10.0μ or more and / or volume average distribution of 12.7
When μ is 10% or more, the laser spot cannot be sufficiently reproduced, and the tendency that the so-called scatter and the blur of the image and the character portion and the so-called scattering are increased.

Also, the distribution amount of 5.04μ or less of the number average distribution, so-called fine powder amount is closely related to the scattering amount, and the fine powder amount of 40% or more is
It has been found that the amount of scattering is more than twice the amount of 20% fine powder in the more preferable embodiment. These are not able to move due to contamination of the charger wire, contamination of the developer concentration detector fiber section, accumulation of scattered particles on the sliding section, and scattered toner adhered to the non-image area of the electrostatic latent image on the photosensitive drum. However, the life of the copying machine is significantly shortened by causing fog and poor cleaning.

According to a study by the present inventors, it has been found that the service life and the interval of regular cleaning are 1/2 to 1/4 or less when the amount of scattering is doubled.

On the other hand, if the volume average diameter is 6.0 μm or less, the amount of ultrafine powder increases during toner production, causing fog and image quality deterioration, and at the same time, a great amount of time and energy are required for the pulverization process during the toner production process, which leads to cost increase.

The present invention provides a particle size distribution effect, for example, by the following developing method (hereinafter
When it is applied to J / B development), extremely favorable results are obtained.

In full-color development, the particle size, particle size distribution, cohesion degree, apparent density, triboelectric charge amount, apparent viscosity, etc. of each of the yellow, magenta, cyan and black toners are substantially the same values due to the necessity of using the same image forming method. It is preferable to have Therefore, it is preferable to optimize the types and amounts of the colorant, charge control agent, fluidity improver, etc., as described above.

That is, in FIG. 2, a bias electric field composed of an AC component and a DC component is applied between the developing sleeve 14 and the photosensitive drum 11 having an electrostatic latent image, and the developing sleeve 14 and the photosensitive drum 11 are
The volume occupied by the carrier in the developing portion of the developing sleeve 14 is 0.5 to 40%, preferably 1.0 to 30% with respect to the volume of the space formed by and the electric field of the AC component has a frequency of 1000 to 3000 Hz. The peak-to-peak voltage is a voltage that does not destroy the electrostatic latent image and moves the carrier between the developing sleeve 14 and the photosensitive drum 11 in the developing area. This is a method of transferring and developing the toner adhering to the surface onto the photosensitive drum 11.

The volume ratio of the carriers present in the developing section is (M / h) ×
It can be calculated by (I / ρ) × [C / (T + C)].

Where M is the amount of developer applied per unit area of the developing sleeve (g / cm ² ), h is the height of the developing space (cm), ρ is the true density of the carrier (g / cm ³ ), C / (T + C) is the weight ratio (%) of the carrier in the developer on the sleeve.

As an example of using the kit and developer of the present invention, M is 0.03 to 0.09 g / cm ² , h is 0.02 to 0.10 cm, and ρ is 4
^{~6g / cm 3, C / (} T + C) can be mentioned value of 91 to 98%.

The charge amount of the toner on the developing sleeve in J / B development is measured by directly absorbing the developer from the sleeve, separating the toner from the carrier, and then introducing the toner to a Faraday gauge. The charge amount of the toner in the developer on the sleeve in the J / B development when the developer of the present invention is used may be a value of −10 to −50 μc / g.

This developing method has a high developing efficiency, is very useful in terms of weight saving and / or downsizing of the apparatus, and is preferable for downsizing of a full-color copying machine. In terms of image quality, it is a method capable of obtaining high image density and less negative development and fogging. The range of the triboelectrification amount characteristics of the full-color toner kit of the present invention with respect to the styrene resin coated ferrite carrier having 250 mesh and 350 mesh particles of the carrier particles of 70% by weight or more and 400 mesh particles of 20% by weight or less is -10 to -50 μc. / g, preferably -15 to -4
It is 5 μc / g, more preferably −20 to −35 μc / g.

The above coated ferrite carrier has an effect of characteristically drawing out the color toner charging characteristics in J / B development.

If it is -10 μc / g or less, scattering from the developing sleeve during development is not remarkable, and scattering in the copier is caused under a high temperature and high humidity environment (30 ° C., 80% RH), making it practically unusable.

Further, if it is -50 μc / g or more, it is practically normal temperature and low humidity environment (2
At 0 ° C., 10% RH), the toner electrostatically and firmly adheres to the carrier surface, making it impossible to transfer the toner onto the photosensitive drum having an electrostatic latent image. FIG. 3 shows the tendency of environmental dependence of the triboelectric charge amounts of the examples and comparative examples.

In order to achieve the above charge amount, it is necessary to use two or more kinds of fluidity improvers. A small particle diameter toner having a volume average of 6.0 to 10.0 μ, such as the toner of the present invention, tends to have an excessive charge amount due to an increase in surface area, especially under low humidity. Therefore, it is necessary to use a fluidity improver having a low charging property such as alumina or titanium oxide. Also, since the toner particle size is small, there are many points of contact between the toner particles, and the fluidity is poor. However, the above-mentioned alumina, titanium oxide and the like do not sufficiently improve the fluidity. Further, on the contrary, there may occur a case where the charge amount is too low. Therefore, it is necessary to jointly use a negatively chargeable fluidity improver having a high fluidity imparting effect such as hydrophobic silica.

That is, by using two or more kinds of fluidity improvers together, it is possible to make the charge amount appropriate and to provide sufficient fluidity. However, in the case of a black toner using a carbon black, since the carbon black is conductive, the charge amount does not become excessive, and it is not necessary to add a low-charge substance.

As the low-charged fluidity improver used in the present invention, all known ones can be used, but preferred examples include alumina and titanium oxide. Preferably BE
The specific surface area by the T method is preferably in the range of 30 to 200 m ² / g,
The range of 80 to 150 m ² / g is more preferable. The reason is that alumina having a BET specific surface area of more than 200 m ² / g and titanium oxide have sufficient fluidity, but the adverse effects tend to result in a toner that easily deteriorates. Degradation is manifested as development in which the amount of charge changes significantly and the fluidity of the developer deteriorates when copying is continued while toner consumption is low.

Further, with alumina having a BET specific surface area smaller than 30 m ² / g and titanium oxide, it is difficult to obtain sufficient fluidity even when used in combination with other fluidity imparting agents. In addition, the fluidity-imparting agent is likely to be insufficiently dispersed, resulting in fog in the image.

As the fluidity-improving agent having a high fluidity-imparting property, all the known fluidity improvers having a negative charging property can be used, but a fine powder produced by vapor phase oxidation of a silicon halogen compound is preferable. The so-called dry process silica or fumed silica, which is produced by a conventionally known technique, can be mentioned. 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 composite powder of silica and another metal oxide is obtained. It is possible to obtain, and they are included.

The particle size is preferably in the range of 0.001 to 2 μ as an average primary particle size, and particularly preferably, silica fine powder in the range of 0.002 to 0.2 μ is used.

Furthermore, 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 powders so that the hydrophobicity measured by the methanol titration test has a value in the range of 30 to 80 are particularly preferable.

As a method of hydrophobizing, it is imparted by reacting with silica fine powder or chemically treating with an organic silicon compound which physically adsorbs.

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 include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane,
Allylphenyldichlorosilane, benzyldimethylchlorosilane, brommethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorgano Silyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane,
Hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane and 2 to 12 siloxane units per molecule, one for each unend unit There is dimethylpolysiloxa containing a hydroxyl group bonded to Si. These are used alone or as a mixture of two or more.

The treated silica fine powder preferably has a particle size in the range of 0.003 to 0.1 μ. As a commercial product,
Taranox-500 (Tarco), AEROSIL R-972
(Japan Aerosil).

It is also preferable to add a friction reducing agent to the toner according to the present invention in order to prevent toner sticking on the photoconductor and cleaning failure during the cleaning process for removing the residual toner on the photoconductor. It is also preferred to add a friction reducing agent. Friction reducing agents include iron oxide, chromium oxide,
Examples thereof include calcium titanate, strontium titanate, barium titanate, magnesium titanate, cerium oxide, zirconium oxide and zinc oxide.

The friction reducing agent is often used in black single-color copies, and the other three colors already have two or more types of fluidity improvers added as described above, which makes it difficult to disperse them sufficiently. It is desirable to add it to the toner.

In the full-color toner kit, the fixability of the toner is a very important factor from the viewpoint of color mixing.

The toner is laminated in multiple layers on the transfer support, and the color is mixed by one fixing, and various colors are expressed according to the toner coating amount on the transfer material. Therefore, the toner particles can be distinguished under a microscope. If the fixing property is not so good, the fixing toner particles diffusely reflect light, resulting in a murky image with reduced saturation, which in turn leads to a reduction in color reproducibility.

Also, when copying to an OHP film, if the fixing property is poor, the light transmission is poor, and although the desired color tone is reproduced with reflected light, dark gray may occur with transmitted light.

However, if only the fixing property is taken into consideration, a high temperature offset, winding around the fixing roller, and provision of a device for applying a large amount of oil to prevent such a situation would complicate the fixing device and increase the cost. Further, the quality of the image is deteriorated due to traces of oil on the copied image.

However, the present invention has an apparent viscosity at 90 ° C. of 5 × 10 ⁴ to
5 × 10 ⁶ poise, preferably 7.5 × 10 ⁴ to 2 × 10 ⁶ poise,
It is more preferably 10 ⁵ to 10 ⁶ poise, and the apparent viscosity at 100 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, preferably 10 ^{4 to} 3.0.
The fixing property, the color mixing property and the high temperature offset resistance of the full-color toner are ensured by adjusting the density to 10 ⁵ poise, more preferably 10 ⁴ to 2 10 ⁵ poise.

Especially, the absolute value of the difference between the apparent viscosity P _{1 at} 90 ° C and the apparent viscosity P _{2 at} 100 ° C is 2 × 10 ⁵ <| P ₂ −P ₁ | <4 × 1
It is preferably in the range of 0 ⁶ .

At the same time, the endothermic peak value in DSC (Differential Thermal Analysis) also correlates with the fixability. Too high a peak value deteriorates the fixability, and if it is too low, there is a problem with storage stability, especially during shipping. There is a case where the temperature rises in the hold and blocking occurs in the toner bolt.

However, for the fixability of color toner,
Good results cannot be expected unless both the apparent viscosity of 00 ° C and the endothermic peak temperature of DSC are satisfied.

In the present invention, it is desirable that the temperature of the endothermic peak of DSC is in the range of 58 to 72 ° C, preferably 61 to 70 ° C, more preferably 70 to 62 ° C.

In order to achieve the apparent viscosity at 90 ° C. and 100 ° C. and the endothermic peak value of DSC of the present invention, the monomer composition of the binder resin, the monomer species, the cross-linking agent, the selection of the initiator, and the production conditions must be carefully set. I have to. Common prints and photographs have a fairly glossy surface, which serves to enhance image quality.

Since the image forming method of the full-color copying method is different from that of printing, the image glossiness is a much more important factor in improving the quality of a color electrophotographic image than in printing or photography.

The gloss range is 5.0% or more, more preferably 7.0% or more. If it is 5.0% or less, the reproducibility of the color tone is poor and the image is sunk and dull, and the image quality is significantly deteriorated.

This glossiness is closely correlated with the thermal properties of the binder resin and the compatibility of the colorant contained in the resin, and in order to obtain the preferred embodiment, the thermal properties of the present invention can be satisfied and the kneading properties It is also necessary to consider dispersibility.

When a full-color toner kit is used, its chromaticity determines the range of color reproducibility, and it is necessary that each color such as yellow, magenta, cyan, and black be balanced.

If the saturation of the yellow, magenta or cyan toner is extremely reduced or the hue is deviated, the degree of freedom in color reproducibility of the color hexagon shown in FIG. 4 is limited.

Green is obtained by superimposing cyan and yellow toners, but the saturation is most likely to be reduced even when compared with other superimposing colors, that is, blue and red.

Therefore, unless the chromaticity of cyan and yellow is above a certain level, a green with good color tone and saturation is not desirable.

Therefore, the colorant selection should be as saturated as possible and take into account the color balance. Specifically, the chromaticity color circle in Fig. 4 should be a preferable hexagon to obtain the maximum area. Must be selected.

Furthermore, each color of magenta, cyan, and yellow must be such that the reflectance is 40% or more, which can be sufficiently distinguished from the carrier in the developer detection.

Therefore, the range of chromaticity of each toner used in the present invention must have the following values.

Yellow toner: a ^* is -6.5 to -26.5, preferably -11.5 to -21.5, more preferably -12.5 to -20.5, b ^* is 73.0 to 93.0, preferably 78.0 to 88.0, more preferably 79.0 to 87.0, L ^* Is 77.0-97.0, preferably 82.0-92.0, more preferably 83.0-91.0, magenta toner: a ^* is 60.0-80.0, preferably 65.0-75.0, more preferably 66.0-74.0, b ^* is -12.0--32.0 , Preferably −17.0 to −27.0, more preferably −18.0 to −26.0, L ^* is 40.0 to 60.0, preferably 40.0 to 55.0, more preferably 44.0 to 54.0, cyan toner: a ^* is −8 to −28.0, Preferably -10.0 to -27.0, more preferably -14.0 to -25.0, b ^* is -30.0 to -50.0, preferably -33.0 to -45.0, more preferably -35.0 to -44.0, L ^* is 39.0 to 59.0, Preferably 44.0-59.0, more preferably 45.0-57.0, black toner: a ^* is -2.0-3.0, preferably -1.0-2. 0, b ^* is -1.0 to 3.0, preferably 0 to 2.0, L ^* is 26.0 to 45.0, preferably 30.0 to 40.0 Furthermore, the relationship between the color toners of the color kit of the present invention is as follows.
It is preferable that the following conditions are satisfied on the chromaticity diagram.

(I) The angle between cyan and yellow: 145 ° ± 15 ° (ii) The angle between cyan and magenta: 95 ° ± 15 ° (iii) The angle between magenta and yellow: 120 ° ± 10 ° where The angle formed by cyan and yellow means the angle formed by the two straight lines connecting the cyan coordinate and the zero point and the yellow coordinate and the zero point on the chromaticity diagram with straight lines. Is. The same applies to cyan and magenta and magenta and yellow.

As the binder resin for toner of the present invention, the following resins can be used within the range not impairing the gist of the present invention.

For example polystyrene, chloropolystyrene, poly-α-
Methylstyrene, styrene-chlorostyrene copolymer,
Styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-
Vinyl acetate copolymer, styrene-maleic acid copolymer,
Styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate Copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer Etc.), styrene-α-chloromethyl acrylate copolymers, styrene-styrene resins such as acrylonitrile-acrylic acid ester copolymers (styrene or styrene-substituted homopolymers or copolymers),
Vinyl chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenyl resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl There are acrylate copolymers, xylene resins, polyvinyl butyral resins and the like. In the practice of the present invention, particularly preferable resins include styrene-acrylic acid ester resins and polyester resins.

In particular, (Wherein R is an ethylene or propylene group, x and y are positive integers of 1 or more, and the average value of x + y is 2 to 10) or a bisphenol derivative or a substituted product thereof. Is a diol component, and a carboxylic acid component consisting of di- or higher-valent galbonic acid or its acid anhydride or its lower alkyl ester (eg, fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid) And the like) are more preferable because they have a sharp melting property.

As the carrier used in the present invention, for example, surface-oxidized or unoxidized metals such as iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earths, and alloys or oxides thereof, and ferrites can be used. Alternatively, there are no particular restrictions on the manufacturing method.

Further, the system in which the surface of the carrier is coated with a resin or the like is particularly preferable in the above-mentioned J / B developing method. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a solvent and applying the coating material to adhere it to the carrier, or a method of simply mixing with a powder can be applied.

The substance adhered to the carrier surface varies depending on the toner material, but for example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal complex of ditertiary butylsalicylic acid, styrene resin, Acrylic resins, polyamides, polyvinyl butyral, nigrosine, amino acrylate resins, basic dyes and their lakes, silica fine powder, alumina fine powder and the like are suitable, but not limited thereto.

The amount of the above compound to be treated may be appropriately determined so that the carrier satisfies the above conditions, but generally, the total amount is preferably 0.1 to 30% by weight (preferably 0.5 to 20% by weight) based on the carrier of the present invention.

The average particle size of these carriers is 20-100μ, preferably 25
It is preferred to have ˜70 μ, more preferably 30-65 μ.

In a particularly preferred embodiment, Cu-Zn-Fe ternary ferrite is used, and the surface thereof is made of styrene-based resin such as styrene-2-ethylhexyl acrylate or styrene-2-ethylhexyl acrylate-methyl methacrylate. .
A coated ferrite carrier having an average particle size of 01 to 5% by weight, preferably 0.1 to 1% by weight, and having 250 mesh or 350 mesh particles having a carrier particle content of 65 weight% or more and 400 mesh particle content of 20 weight% or less. There are some.

The above-mentioned coated ferrite carrier has a sharp particle size distribution, and has a preferable triboelectrification property for the color toner kit of the present invention, and further has an effect of improving electrophotographic characteristics.

When a two-component developer is prepared by mixing with the color toner according to the present invention, the mixing ratio is 2.0 wt% to 9 wt%, preferably 3.0 wt% to 8.0 wt% as the toner concentration in the developer.
Good results are usually obtained with a weight percentage. If the toner density is 2.0% or less, the image density will be too low to be practical and 9.0%.
In the above, the fog and the scattering in the machine are increased, and the useful life of the developer is shortened.

The amount of addition to the colorant-containing resin particles, the resin particles 10
It is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, relative to 0 parts by weight. If it is less than 0.01 parts by weight, there is no effect on improving the fluidity, and if it is more than 10 parts by weight, fog and bleeding of letters and scattering in the machine are promoted.

Examples of magenta, cyan, and yellow colorants suitable for the purpose of the present invention include the following pigments and dyes. still,
In the present invention, CI Disperse Y164, CISo having poor light resistance
Colorants such as lvent Y77 and CI Solvent Y93 are non-promotional.

Examples of the dye include CI direct red 1, CI direct red 4, CI acidic red 1, CI basic red 1, CI modern red 30, CI direct blue 1, CI direct blue 2, CI acidic blue 9, CI acidic blue 15, CI basic blue. Blue 3, CI Basic Blue 5, CI Modern Blue 7
Etc.

As pigments, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Permanent Orange G
TR, Pyrazolone Orange, Benzene Orange G, Permanent Red 4R, Watching Red Calcium Salt, Brilliant Carmine 3B, Quinacridone Red, Fast Violet B, Methyl Violet Lake, Phthalocyanine Blue, Farst Sky Blue, Indance Lane Blue BC etc.

Disazo yellow, insoluble azo, quinacridone, copper phthalocyanine are suitable as pigments, and basic dyes and oil-soluble dyes are suitable as dyes.

CI Pigment Yellow 17, CI Pigment Yellow 15, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 12, CI Pigment Red 5, CI Pigment Red 3, CI Pigment Red 2, CI Pigment Red 6, CI Pigment 7, CI Pigment Red 122, CI Pigment Red 202, CI Pigment Blue 15, CI Pigment Blue 16, or structural formula (I) shown below, having a carboxybenzamide methyl group in the phthalocyanine skeleton 2 A copper phthalocyanine pigment, which is a Ba salt having 3 to 3 substitutions.

Examples of the dye include CI solvent red 49, CI solvent red 52, CI solvent red 109, CI basic clad 12, CI basic clad 1, and CI basic clad 3b.

The content of the yellow toner, which is sensitively reflected by the transparency of the OHP film, is 12 parts by weight or less, preferably 0.5 to 7 parts by weight based on 100 parts by weight of the binder resin.
Parts by weight are desirable.

If it is 12 parts by weight or more, the reproducibility of green and red, which is a mixture of yellow, and human skin color as an image is poor.

For other magenta and cyan color toners,
The amount is preferably 15 parts by weight or less, more preferably 0.1 to 9 parts by weight or less with respect to 100 parts by weight of the binder resin.

As the carbon black used in the black toner of the present invention, all known carbon blacks such as channel black, furnace black and lamp black can be used. The content thereof is preferably 10 parts by weight or less, more preferably 7 parts by weight or less with respect to 100 parts by weight of the binder resin.

It is also preferable to blend a charge control agent in the toner according to the present invention in order to stabilize the negative charge characteristics. At this time, a colorless or pale-colored negatively chargeable control agent that does not affect the color tone of the toner is preferable. Examples of the negative charge control agent include organic metal complexes such as metal complexes of alkyl-substituted salicylic acid (for example, chromium complex or zinc complex of ditersialybutylsalicylic acid). When compounding the negative charge control agent with the toner, 0.1 to 10 parts by weight per 100 parts by weight of the binder resin is used.
It is preferable to add 0.5 part by weight, preferably 0.5 to 8 parts by weight.

Each measuring method (1) to (10) of the present invention will be described below.

(1) Particle size distribution measurement: An interface (manufactured by Nikkaki) and a CX-1 personal computer (Canon) which output a number average distribution and a volume average distribution using a Coulter Counter TA-II type (manufactured by Coulter) as a measuring device Made) and the electrolytic solution is 1
Prepare a 1% NaCl aqueous solution using graded sodium chloride.

As a measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate as a dispersant is added to 100 to 150 ml of the aqueous solution of the electric field, and 0.5 to 50 mg of a measurement sample is further added.

The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the Coulter Counter TAII type is used to make the dispersion 2 to 40 by using a 100 μ aperture.
The particle size distribution of μ particles is measured to obtain the volume average distribution and number average distribution.

From these volume distribution and number distribution, volume average particle size, number average distribution of 6.35μ or less, volume average distribution of 20.2μ
The above values are obtained.

(2) Measurement of fluidity index: The fluidity index is used as one means for measuring the fluidity characteristics of a sample (a toner having an external additive, etc.). The larger the value of the fluidity index, the more the fluidity of the sample. Judge as bad.

A powder tester (manufactured by Hosokawa Micron Co., Ltd.) is used as the measuring device.

The measurement environment is 23 ℃ and 60% RH.

(1) After leaving the toner in the measurement environment for 12 hours, weigh 5.0 g accurately.

(2) From the top, set a sieve of mesh 150μ, wire diameter 104μ (100 mesh), mesh opening 75μ, wire diameter 52μ (200 mesh), mesh 38μ, wire diameter 27μ (400 mesh) from above. .

(3) Gently weigh 5.0 g of toner onto a sieve (100 mesh), and vibrate for 15 seconds with an amplitude of 1 mm.

(4) Gently weigh accurately the amount of toner remaining on each sieve.

Fluidity index (%) = a + b + c (3) Apparent density measurement: The apparent density is measured using a powder tester (manufactured by Hosokawa Micron). For the measurement, place 60 mesh sieve on the vibrating table, and place an apparent density measuring cup (internal capacity 100cc) whose weight is measured directly underneath.

Next, adjust the rheostat scale to 2.0 and start vibration. The measurement sample is gently discharged from the vibrating upper part of the 60 mesh sieve so as to enter the measurement cup.

When the cups are filled with the sample, the vibration is stopped, the upper surface of the cups is scraped off with a blade, and the balance is accurately weighed.

Since the measuring cup has an internal capacity of 100 cc, it can be calculated from the apparent density (g / cm ³ ) = sample weight ÷ 100.

In addition, the sample used was left for about 12 hours in an environment of 23 ° C. and 60% RH, and the measurement environment was 23 ° C. and 60% RH.

(4) Apparent viscosity measurement: A flow tester CFT-500 type (manufactured by Shimadzu Corporation) is used.
As for the sample, weigh about 60 to 60 g of bath product. Using a molding machine, this is pressed for 1 minute with a load of 100 kg / cm ² .

This pressurized sample is stored under normal temperature and humidity conditions (temperature approx.
A flow tester measurement is performed at 20 to 30 ° C and a humidity of 30 to 70% RH to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the apparent viscosities at 90 ° C. and 100 ° C. are determined and used as the apparent viscosities with respect to the temperature of the sample.

RATE TEMP 6.0D / M (℃ 1 minute) SET TEMP 70.0DEG (℃) MAX TEMP 200.0DEG INTERVAL 3.0DEG PREHEAT 300.0SEC (sec) LOAD 20.0KGF (kg) DIE (DIA) 1.0MM (mm) DIE (LENG) 1.0MM PLUNGER 1.0CM ² (cm ² ) (5) Chromaticity measurement: Yellow, magenta, cyan, black, and magenta = yellow, magenta = cyan, cyan = yellow, which is a combination of red and blue green. Prepare a solid image of.

At this time, using a laser color copying machine (made by Canon),
Yellow, magenta, cyan, black developer density 9 ~
Set to 10%, potential contrast 150-250V, 23 ℃, 60%
It is preferable to use an image rendered in an RH environment.

The spectral reflectances of these solid images are measured in the range of 390 to 730 nm with a CA-35 type high-speed spectrophotometer (manufactured by Murakami Color Research Laboratory).

The transfer paper used at the time of measurement should be plain paper such as sunflower paper and should have an image density of 1.5 ± 0.2. Image density is RD-914 type reflection densitometer (manufactured by Macbeth)
Is preferably used.

Next, based on JIS standard Z-8722, "Method of measuring object color by 2 degree visual field XYZ system", stimulus values of X, Y, Z are obtained, and chromaticity (a ^* , b ^* , L ^* ) is obtained. .

That is, first, a C light source is used as a light source, a 2-degree visual field is used as a color matching function, and X, Y, and Z stimulus values are obtained from the spectral reflectance of the sample at intervals of 10 nm from 390 to 730 nm according to the following equation.

However, C light source is S (λ), color matching function is (λ),
(Λ), (λ), and the spectral reflectance of the sample is R (λ).

Furthermore, from these X, Y, and Z values, the chromaticity (a ^* , b ^* ,
L ^* ).

a ^* = 500 [(X / X ₀ ) ¹ / 3- (Y / Y ₀ ) ^1/3 ] b ^* = 200 [(Y / Y ₀ ) ¹ / 3- (Z / Z ₀ ) ^1/3 ] L ^* = 116 (Y / Y ₀ ) ^1/3 −16 where X ₀ , Y ₀ and Z ₀ are the stimulus values of the light source color, And

(6) Measurement of endothermic peak value by DSC: DSC is an abbreviation for differential thermal analysis.

In the present invention, measurement is performed using a differential thermal analysis measuring device (DSC measuring device), DSC-7 (manufactured by Birkin Elmer Co., Ltd.).

A measurement sample is precisely weighed in an amount of 5 to 20 mg, preferably 10 mg.

This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rising rate of 10 ° C / min under a normal temperature and normal humidity in a measurement temperature range of 30 ° C to 200 ° C.

The temperature at which the endothermic peak of the main peak in the temperature range of 40 to 100 ° C. is obtained in this temperature rising process is taken as the endothermic peak value of the present invention.

(7) Measurement of triboelectric charge amount: The measuring method will be described in detail with reference to the drawings.

FIG. 6 is an explanatory diagram of an apparatus for measuring the triboelectric charge amount of toner. First, a metal measuring container 22 having a screen 23 of 500 mesh at the bottom is mixed in the same mixing ratio as that when the toner and the carrier for which the triboelectric charge is to be measured are actually used as a developer, and the volume is 50 to 100 ml. In a polyethylene bottle and shaken by hand for about 10 to 40 seconds, and about 0.5 to 1.5 g of the mixture (developer) is put into the lid 24 made of metal. At this time, the total weight of the measurement container 22 is weighed and set as W ₁ (g). Next, in the suction device 21 (at least the portion in contact with the measurement container 22 is an insulator), suction is performed from the suction port 27 to adjust the air volume control valve 26, and the pressure of the vacuum gauge 25 is set to 250 mmAq. In this state, the toner is suctioned sufficiently, preferably for 2 minutes to remove the toner by suction. The potential of the electrometer 29 at this time is V (volt).
Here, 28 is a condenser, and the capacity of is C (μF)
And In addition, weigh the entire measuring container after suction and
₂ (g). The triboelectric charge amount (μc / g) of this toner is calculated by the following formula.

The carrier used for the measurement is a styrene resin-coated ferrite carrier having 250-mesh paths and 350-meshion carrier particles having 70 to 90% by weight of carrier particles. That is, a ferrite carrier coated with 0.2 to 0.7% by weight of styrene-2-ethylhexyl acrylate-methyl methacrylate is used.

The sample toner and carrier used for measurement should be left for at least 12 hours in an environment of 23 ° C and 60% RH before being used for measurement of charge amount.

Also, the measurement of triboelectrification amount is performed in an environment of 23 ° C and 60% RH.

(8) Gloss measurement: Using a VG-10 type gloss meter (manufactured by Nippon Denshoku Co., Ltd.), each solid image used for chromaticity measurement is used as a sample image for measurement.

For measurement, first set to 6V with a constant voltage device.

Then set the projection angle and the reception angle to 60 °.

Using the 0-point adjustment and the standard plate, after the standard setting, the sample image is placed on the sample table, three white papers are overlaid and measured, and the numerical value shown in the marking part is read in%.

At this time, S, S / 10 switch SW is set to S, and angle and sensitivity switch SW
Adjust to 45-60.

Use a sample with an image density of 1.5 ± 0.1.

(9) Spectral reflectance measurement: After transfer of each of yellow, magenta, cyan, and black, an unfixed image is prepared.

Since the developer density is detected by measuring the reflectance in the near infrared region of each color toner particle and the carrier, it is necessary to measure the unfixed image and read the reflectance of the toner particle on the transfer material.

As a device, DK-2A spectrophotometer (manufactured by Beckmann)
Is used to measure the spectral reflectance in the range of 700 to 1050 nm.

(10) Hydrophobicity measurement: The methanol titration test is an experimental test for confirming the hydrophobicity of silica fine powder having a hydrophobized surface.

Defined herein to evaluate the degree of hydrophobicity of treated silica fines. The "methanol titration test" is performed as follows. 0.2 g of the fine silica powder to be tested is added to 50 ml of water in an Erlenmeyer flask having a volume of 250 ml. Methanol is titrated from the bath until the total amount of silica is wet. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by suspending the total amount of silica fines in the liquid and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

Hereinafter, the present invention will be described in detail with reference to examples and drawings. In addition, "%" and "part" show a weight% and a weight part.

In the present invention, each color toner may be stored in a toner container such as an individual bolt at the time of storage, or a four-color toner kit may be formed in the copying machine after the toner is replenished in the copying machine. Also, one toner container may be divided into four chambers, and each chamber may contain magenta, cyan, yellow, or black toner to form a full-color toner kit form. In any case, finally, in the full-color copying machine, the toners of four colors are present as kits to form the full-color toner kit of the present invention.

Example 1 A 100% by weight of a polyester resin obtained by condensing propoxylated bisphenol and fumaric acid was used to obtain a full-color toner kit using the following formulation amounts of a colorant and a charge control agent.

The production method is as follows. The above prescription amounts are sufficiently premixed with a Henschel mixer, melt-kneaded with a three-roll mill at least twice, and after cooling, coarsely pulverized to about 1 to 2 mm using a hammer mill, It was pulverized to a particle size of 40 μm or less with an air jet type pulverizer. Further classifying the resulting finely pulverized product, selecting 2 ~ 23μ so as to have the particle size distribution of the present invention, silica fine powder treated with hexamethyldisilazane as a fluidity improver 100 parts by weight of each classified product 0.5 parts by weight, magenta, cyan, and yellow toners, 0.3 parts by weight of fine alumina powder having a specific surface area of 100 m ² / g by the BET method, and black toner, 0.5 parts by weight of strontium titanate, respectively. Toner.

Also, about 0.5 wt% of styrene-2-ethylhexyl acrylate-methyl methacrylate (copolymerization ratio 45:25:35) was coated, Cu-Zn-Fe based ferrite carrier (average particle size 47μ; 250 mesh pass, 350 mesh pass). 77 wt%; 400 mesh pass 13 wt%; true density of 5.1 g / cm ³ was mixed to obtain a toner concentration of 4% for magenta, 5.5% for cyan and yellow, and 5% for black to obtain a developer.

FIG. 5 shows the spectral reflectance in the near infrared region of these color toners other than black and the coated carriers used. It was found that the difference in reflectance was large at 900 to 1000 nm.

A copying test was carried out using a color electrophotographic apparatus having an OPC photosensitive drum and a replenishment-developing system shown in FIGS.

Development and transfer of each color toner were performed in the order of magenta toner, cyan toner, yellow toner, and black toner. At the time of transfer, transfer commutation to be passed through a transfer corotron was performed at 140 mA for magenta toner, 180 mA for cyan toner, 230 mA for yellow toner, and 290 mA for black toner.

An example of the replenishment-developing system used in the present invention will be described.
The replenishment toner sent by the supply screw 13 in the toner conveying cable 4 is connected to the developing device 2 through the toner replenishing port 5 and is supplied into the developing device.

When the developing device rotates and comes to a position facing the photosensitive drum 1, the replenishment toner is uniformly mixed with the developer within an extremely short time by the mixing-conveying screws 16 and 17, so that the developer having a constant developer concentration is developed. Become an agent.

The developer is applied to the developer regulating blade 15 on the developing sleeve 12.
Causes a certain amount of developer, and the negatively-charged toner is transferred onto the photosensitive drum by the reversal development method using the J / B development method at the facing portion of the photosensitive drum 1 having the negatively-charged electrostatic latent image. is there. In this embodiment, the distance between the sleeve and the photosensitive drum in the developing area is set to 600 μm.

Using this method, a full-color image with a much higher definition than that of the conventional one, which faithfully reproduces the original color chart without fog even after printing 20 million sheets in full-color mode, was obtained. Further, conveyance in the copying machine and detection of developer concentration were good, and stable image density was obtained. The transparency of the toner was very favorable even when the OHP film was used. In addition, cleaning failure did not occur.

The triboelectric charge amounts of the yellow, magenta, cyan and black toners of the present invention are −28.5 μc / g, −29.2 μc / g and 30.1 μc / g, respectively.
g, −29.8 μc / g. FIG. 3 shows the environmental dependence of the cyan toner on the triboelectric charge amount.

The chromaticity diagram at this time is shown in FIG. 4, and the values and the glossiness of each color toner are as follows.

Each value of each color developer in the developing area in this embodiment is shown below.

The apparent viscosities at 90 ° C and 100 ° C and the endothermic peak values of DSC were as follows.

Further, the particle size distribution, aggregation degree, and apparent density of the toner composition of the present invention are as follows.

Example 2 A durability test was conducted in the same manner as in Example 1 except that the magenta colorant was changed to 1.0 part by weight of CI Basicktlets 12 and 0.3 parts by weight of CI disperse violet 31. A good image was obtained. The physical properties of the toner used are shown in Table 4.

Example 3 The colorant for cyan was changed to 5.5 parts of CI Pigment Blue 15, and the colorant for yellow was CI Disperse Yellow 54.
Was tested in the same manner as in Example 1 except that the amount was 2.5 parts. An image with good fog-free color balance was obtained. The physical properties of the toner used are shown in Table 4.

Example 4 The same test as in Example 1 was carried out except that the colorant for yellow was changed to 5.0 parts by weight of CI Pigment Yellow 13; however, a durable transportability and a performance having no problem in developer mixing property were obtained. It was The physical properties of the toner used are shown in Table 4.

Example 5 A 15,000-sheet durability test was conducted in the same manner as in Example 1 except that the colorant for black was changed to 3.2 parts of channel carbon black, and a high-definition and fog-free image was obtained. In addition, cleaning failure did not occur. The physical properties of the toner used are shown in Table 4.

Comparative Example 1 In Example 1, the black toner has a volume average diameter of 12.2μ and a particle size distribution of 5.04μ or less 31.1%, 12, 7μ or more 15.1%, and a broad particle size distribution. Caused the backside of the transfer paper to be smeared at 0.5 million sheets. Also, the laser spot was not faithfully reproduced, and the halftone reproducibility was deteriorated.

Comparative Example 2 When only the fine silica powder was added to the cyan toner in Example 1, a charge gap with the carrier was generated, and the image density was considerably reduced to 0.7 or less according to the Macbeth reflection densitometer.

Comparative Example 3 The same test as in Example 1 was conducted except that the colorant for magenta was changed to 3.0 parts by weight of CI Pigment 57, but the color saturation was deteriorated and the color reproducibility was poor. Magenta toner a ^*
Was 63.1, b ^* was -3.5, and L ^* was 24.0, all of which deviated from the values specified in the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a color electrophotographic copying machine to which the color toner kit of the present invention is applied.
FIG. 3 is an enlarged cross-sectional view of the replenishing system-developing system portion of the copying machine shown in FIG. 1, and FIG. 3 is an environmental change and triboelectric charging of the cyan toner of Example 1 and the magenta toner of Comparative Example 2. FIG. 4 is a graph showing the relationship with the amount, and FIG. 4 shows the chromaticity of the yellow toner, magenta toner, cyan toner, and black toner in Example 1, the chromaticity of the red color due to the superposition of magenta toner and yellow toner, and magenta toner. 5 is a chromaticity diagram showing the chromaticity of blue color due to the superposition of cyan toner and cyan toner, the chromaticity of green color due to the superposition of cyan toner and yellow toner, and the chromaticity of the magenta toner of Comparative Example 3. FIG. FIG. 6 is a graph showing the relationship between the spectral reflectance and the wavelength of each toner and carrier other than black used in Example 1, and FIG. 6 schematically shows an apparatus for measuring the triboelectric charge amount of toner. It is a diagram.

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Claims (5)

[Claims] 1. A full-color toner kit for multicolor electrophotography comprising at least a yellow toner, a magenta toner, a cyan toner and a black toner, wherein the yellow toner comprises yellow colorant-containing resin particles and two or more fluidity improvers. It has a volume average particle size of 6.0 to 10.0μ and a number average distribution of 5.04μ or less is 40%.
Below, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to
1.5 g / cm ³ , and the apparent viscosity of the yellow toner at 100 ° C. and 90 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5
Within the range of × 10 ⁶ poise, DSC endothermic peak value is 58 to 72
C., the gloss is 5.0% or more, and contains 0.1 to 12.0 parts by weight of a yellow colorant with respect to 100 parts by weight of the binder resin,
The chromaticity of the yellow toner is a ^* −6.5 to 26.5, b ^* 73.0 to 93.0
And L ^* 77.0 to 97.0, and 250 or 350 mesh particles of the carrier particles are 65% by weight or more and 400 mesh particles are 20% or less by weight, and the triboelectric property of styrene resin coated ferrite carrier is -10 to -50μ.
The magenta toner has magenta colorant-containing resin particles and two or more types of fluidity improvers, and its particle size distribution is a volume average particle size of 6.0 to 10.0 μ and a number average distribution. 40% is 5.04μ or less
Below, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to
It is 1.5 g / cm ³ , and the apparent viscosity of the magenta toner at 100 ° C. and 90 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5
Within the range of × 10 ⁶ poise, DSC endothermic peak value is 58 to 72
C., the gloss is 5.0% or more, 0.1 to 15.0 parts by weight of a magenta colorant with respect to 100 parts by weight of the binder resin, the chromaticity of the magenta toner is a ^* 60.0 to 80.0, b ^* -12.0 ~ −32.
0 and L ^* 40.0 to 60.0, having a content of 250 mesh, 350 mesh of carrier particles of 65% by weight or more and 400 mesh of 20% by weight or less, the triboelectrification characteristic of the styrene resin coated ferrite carrier is -10 to −50
The cyan toner has a cyan colorant-containing resin particle and two or more types of fluidity improvers, and its particle size distribution is a volume average particle size of 6.0 to 10.0 μ and a number average distribution. 5.04μ or less is 40% or less, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to 1.5.
g / cm ³ , the apparent viscosity of the cyan toner at 100 ° C. and 90 ° C. is in the range of 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5 × 10 ⁶ poise, and the endothermic peak value of DSC is The temperature is 58 to 72 ° C., the gloss is 5.0% or more, and the cyan colorant is contained in an amount of 0.1 to 15.0 parts by weight based on 100 parts by weight of the binder resin, and the chromaticity of the cyan toner is a ^* −8 to −. 28.0, b ^* −30.0 to −50.0 and L
^* 39.0 to 59.0, 250 mesh, 350 mesh particles of 65% by weight or more of carrier particles, 400 mesh of 20% by weight or less, styrene resin coated Ferlite carrier friction charge amount characteristics -10 ~ -50μc / g
Wherein the black toner is resin particles containing carbon black,
It has a fluidity improver and a friction reducing agent, and its particle size distribution is 4 to 10% in volume average particle size and 5.04μ or less in number average distribution.
0% or less, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is
0.2 to 1.5 g / cm ³ and the apparent viscosity of the black toner at 100 ° C. and 90 ° C. is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ^{4 to} 5
Within the range of × 10 ⁶ poise, DSC endothermic peak value is 58 to 72
C., 0.1 to 10.0 parts by weight of carbon black per 100 parts by weight of the binder resin, and the chromaticity of the black toner is a ^* -
2.0 ~ 3.0, b ^* -1.0 ~ 3.0 and L ^* 26.0 ~ 45.0, 65 wt% carrier particles of 250 mesh pass, 350 mesh pass.
A full-color toner kit having the above characteristics and having a triboelectric charge characteristic of −10 to −50 μc / g with respect to a styrene-based resin-coated ferrite carrier having 400 mesh paths of 20% by weight or less. 2. A yellow developer having a yellow toner and a resin-coated ferrite carrier, wherein the resin-coated ferrite carrier is a styrene-based resin-coated ferrite carrier, and the yellow toner comprises yellow-based colorant-containing resin particles and two or more types of toner particles. With a fluidity improver, the particle size distribution of the toner is volume average particle size of 6.0 to 10.0 μ, number average distribution of 5.04 μ or less is 40% or less, and volume average distribution of 12.7 μ or more is 10% or less. The sex index is 5% or more and 25% or less, and the apparent density is
0.2-1.5 g / cm ³ of the yellow toner at 100 ° C. and 90
The apparent viscosity at ℃ is 10 ⁴ ~5 × 10 ⁵ poise, 5 × 10 ⁴
~ 5 × 10 ⁶ Poise, DSC endothermic peak value is 58
To 72 ° C., a glossiness of 5.0% or more, a yellow colorant is contained in an amount of 0.1 to 12.0 parts by weight with respect to 100 parts by weight of a binder resin, and the chromaticity of the yellow toner is a ^* −6.5 to −26.5, b ^* 73.0
~ 93.0 and L ^* 77.0-97.0, 250 mesh pass, 350
More than 65% by weight of carrier particles of methushion and 40
0 The styrene-based resin coated with 20% by weight or less of mesh pass has a triboelectrification property of -10.
A yellow developer characterized by having a content of -50 μc / g. 3. A magenta developer having a magenta toner and a resin-coated ferrite carrier, wherein the resin-coated ferrite carrier is a styrene-based resin-coated ferrite carrier, and the magenta toner comprises magenta-based colorant-containing resin particles and two or more types of magenta toners. The toner contains a fluidity improver and has a volume average particle diameter of 6.0 to 10.0 μ, a number average distribution of 5.04 μ or less is 40% or less, and a volume average distribution of 12.7 μ or more is 10% or less, The sex index is 5% or more and 25% or less, the apparent density is 0.2 to 1.5 g / cm ³ , and the magenta toner has a temperature of 100 ° C and
Apparent viscosity at 90 ℃ is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10
^{It is in} the range of ^{4 to} 5 × 10 ⁶ poise, and the endothermic peak value of DSC is 5
8 to 72 ° C., a glossiness of 5.0% or more, containing 0.1 to 15.0 parts by weight of a magenta colorant with respect to 100 parts by weight of a binder resin, and the chromaticity of the magenta toner is a ^* 60.0 to 80.0, b ^* -12.0
~ -32.0 and L ^* 40.0-60.0, 250 mesh pass, 35
0 65% by weight or more of carrier particles of mesh and 4
00 styrene resin coat with 20 wt% or less of mesh path
Magenta developer characterized in that it is from -50 μc / g. 4. A cyan developer having a cyan toner and a resin-coated ferrite carrier, wherein the resin-coated ferrite carrier is a styrene-based resin-coated ferrite carrier, and the cyan toner comprises cyan-based colorant-containing resin particles and two or more kinds of cyan toner. The toner contains a fluidity improver and has a volume average particle size of 6.0 to 10.0μ and a number average distribution of 5.04μ or less.
0% or less, 12.7μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is
0.2-1.5 g / cm ³ , 100 ° C and 90 ° C of the cyan toner
Apparent viscosity in 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10 ⁴ to
It is in the range of 5 × 10 ⁶ poise and the endothermic peak value of DSC is 58〜.
The temperature is 72 ° C., the gloss is 5.0% or more, and the cyan colorant is contained in an amount of 0.1 to 15.0 parts by weight based on 100 parts by weight of the binder resin, and the cyan toner has a chromaticity of a ^* −8 to −28.0, b. ^* −30.0 to −50.
0 and L ^* 39.0 to 59.0, having 250 or more mesh particles of 65 wt% or more carrier particles and 400 or less mesh particles of 20 wt% or less, the triboelectrification characteristic of styrene resin coated ferrite carrier is -10 to −50
A cyan developer characterized in that the toner is μc / g. 5. A black developer having a black toner and a resin-coated ferrite carrier, wherein the resin-coated ferrite carrier is a styrene-based resin-coated ferrite carrier, and the black toner is a resin particle containing carbon black,
A toner containing a fluidity improver and a friction reducing agent, and having a particle size distribution of the toner having a volume average particle size of 6.0 to 10.0 μ and a number average distribution of 5.04.
μ or less is 40% or less, 12.7 μ or more of the volume average distribution is 10% or less, the fluidity index is 5% or more and 25% or less, and the apparent density is 0.2 to 1.5 g / cm ³ , 100 ° C and
Apparent viscosity at 90 ℃ is 10 ^{4 to} 5 × 10 ⁵ poise, 5 × 10
^{It is in} the range of ^{4 to} 5 × 10 ⁶ poise, and the endothermic peak value of DSC is 5
8 to 72 ° C., 0.1 to 10.0 parts by weight of carbon black per 100 parts by weight of the binder resin, and the chromaticity of the black toner is a
^* −2.0 to 3.0, b ^* −1.0 to 3.0 and L ^* 26.0 to 45.0, 25
Characteristic of triboelectricity is -10 to -50 μc / g for styrene resin coated ferrite carrier with 0 mesh and 350 mesh particles of 65 wt% or more of carrier particles and 400 mesh of 20 wt% or less. Black developer.