JPH03213875A - Toner for full color development - Google Patents

Abstract

PURPOSE:To improve image reproducibility in full color development by specifying the range of the electrical conductivity of a binder resin. CONSTITUTION:The binder resin having the electrical conductivity which satisfies a 1.0X10<-9> to 5.0X10<-9>(s/cm) range is used. The toner for full color is used by mainly superposing the toner for cyan, the toner for magenta, the toner for yellow, and the toner for black on an image. The particularly important requirement is that electrical conductivity of the binder resin satisfies the 1.0X10<-9> to 5.0X10<-9>(s/cm) range and particularly the 1.0X10<-9> to 3.0X10<-9>(s/cm). The fluctuation in the transfer quantity of the respective toner is eliminated in this way and the full color toner having the excellent reproducibility of the image is obtd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a full-color developing toner that is used in layers with various toners, and more specifically, the present invention relates to a full-color developing toner that is used in layers with various toners, and more specifically, the present invention relates to a full-color developing toner that is used in layers with various toners, and more specifically, the present invention relates to a full-color developing toner that is used in layers with various toners, and more specifically, the present invention relates to a full-color developing toner that is used in layers with various toners. , relates to a full-color developing toner with excellent image reproducibility.

[Prior Art] In the fields of electrophotography and electrostatic printing, toner is used for the purpose of visualizing an electrostatic latent image formed on an image carrier. In this toner, various resins such as styrene resin and polyester resin are used as the resin medium, and the coloring agent is carbon black or other organic resin. Alternatively, inorganic colored pigments are used.

Furthermore, in recent years, full-color development has been carried out in which magenta, cyan, yellow, and black color toners are superimposed to form an image.

Full-color development involves exposing a multicolor document to light using color separation filters, repeating this process multiple times using cyan, yellow, and magenta color developers and black toner, and superimposing the toner images to create a multicolor image. The purpose is to obtain a color image. In toners used for such full color development, organic pigments are used as colorants for cyan, yellow, and magenta toners.
Carbon black is used as the black toner.

FIG. 1 is a diagram showing a developing section and a transfer section of an image forming apparatus that obtains a full-color image. An electrostatic latent image formed on a photosensitive drum 1 by an appropriate means is transferred to a developing device 3a of a vertically moving developing unit 2. , 3b, 3c, and 3d, and is transferred by the transfer charger 5 onto a transfer material held on the transfer drum 4 by the gripper 6 and neutralized by the charger 7. Furthermore, 2
The colors are 3a, 3b, and 3c, which are different from the first color.

The toner image developed by the developer of any of the developing devices 3d is also transferred to the transfer material by the transfer charger, and
The color and the fourth color are also applied in the same manner. In this way, toner images of a predetermined number of colors are multiple-transferred onto the transfer material held on the transfer drum 4, and the transfer material is conveyed to a runner process (not shown) to obtain a full-color image. Generally, in the above-mentioned transfer process, toner of a different color is further transferred onto the toner layer transferred onto the transfer material. In this operation, the electric charge of the toner already transferred onto the transfer material may lower the effective transfer electric field in the next toner transfer operation, so that an image with a desired hue may not be reproduced. For this reason, a method is sometimes taken in which the transfer voltage is increased sequentially or after the third time when the toner layer becomes thicker in the transfer process.

However, the behavior of toner in the actual transfer process is delicate, and even if a predetermined transfer voltage is applied and the voltage value of the transfer voltage is further increased in the subsequent process, the various characteristics of each color toner (charging characteristics, electrical characteristics) ), scattering of the toner often causes transfer defects, and it has not yet been possible to obtain a satisfactory result in obtaining a toner image of the desired color.

Furthermore, as described in Japanese Patent Publication No. 1-32981, the charge of the toner to be developed and transferred is made larger than the absolute value of the charge amount of the toner that has already been developed and transferred to compensate for the decrease in the actual transfer electric field. A method for stabilizing the transfer process has also been proposed, but in this method, the development conditions for each color (photoconductor charging characteristics, development bias, photoconductor -
If you try to standardize the developer carrier (sliding condition), the toner's IF current characteristics will be significantly different, resulting in uneven developability (insufficient density in solid areas, thickening of line and dot images, toner dust around the periphery of the image area) This may cause toner to scatter inside the machine, resulting in hue shifts and blurred images.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the difference in the electrical properties of toner, improve the development properties,
To provide a full-color developing toner that has substantially the same transfer characteristics and can form an image without causing hue shift or image density unevenness under a state where development conditions and transfer conditions are substantially the same.

A further object of the present invention is to provide a full-color developing toner that can stably maintain desired characteristics under set development conditions and transfer conditions and exhibits little change in hue.

[Means for Solving the Problems] According to the present invention, there is provided a full-color developing toner in which a colorant is contained in a binder resin and which is used in combination with another toner containing a different colorant, The conductivity of the binder resin is 1. OX 10-9 to 5.0×1O-9 (s/cm
) A full-color developing toner is provided that satisfies the following range.

The full-color developing toner may be characterized in that the binder resin contains a charge control agent, and the charge control agent is a zinc compound of salicylic acid.

In the full-color developing toner, there is provided a magenta toner characterized in that the colorant contains a quinacridone pigment as a main component.

In the full-color developing toner, a cyan toner is provided, characterized in that the colorant contains a copper phthalocyanine pigment as a main component.

In the toner for full color development, there is provided a toner for yellow, characterized in that the colorant contains a hengedine pigment as a main component.

[Function] In the present invention, the conductivity of the binder resin is 1. By using a toner that satisfies the range of OX 10-9 to 5, Ox 1O-9 (s/cm), it is possible to obtain toner for full-color development of each color with extremely similar electrical properties, and to improve image reproducibility in full-color development. This is based on the knowledge that good products can be obtained.

The full-color toner is mainly used by superimposing a cyan toner, a magenta toner, a yellow toner, and a black toner on an image.

In the present invention, the conductivity of the binder resin is 1, OX
10-9 to 5. It is important to satisfy the range of Ox 1O-9 (s/cm), especially 1. It is desirable to satisfy the range of OX 10-9 to 3.0×1O-9 (s/cm). If the conductivity of the binder resin is smaller than the above range, there will be a large difference in the conductivity of the various toners that are superimposed. For example, as seen in sample 1-3 of the experimental example described below, the binder resin
When a low conductivity m is used, carbon black increases the conductivity of the entire toner by 1.2×1O-9
Set to s/cm. On the other hand, the conductivity of other toners such as cyan, magenta, and yellow is on the order of 10-10 s/cm, and various colorants do not significantly raise the conductivity of the entire toner like carbon black. For this reason, a difference occurs in the conductivity of the four toners stacked on top of each other.

On the other hand, if a binder resin with conductivity within the above range is used,
Even when various colorants such as black, cyan, magenta, and yellow are used, Experimental Examples 1-1 and 1-2
As seen in Figure 2, there is no difference in the conductivity of the various toners. In development and transfer operations using full-color development toners with no difference in conductivity, under the same development conditions, toner scattering and image fog do not occur, the amount of developed toner is constant, and each color is The transferability of the toner is similar, and the hue and image density are stabilized.

Furthermore, if the conductivity is greater than the above range, even if a charge is applied to the toner, the charge will escape quickly! The electrical state becomes unstable, making toner scattering and image fogging more likely to occur.

Note that it is desirable that the binder resin of the toner for full color development has the above-mentioned electrical conductivity and is excellent in light transmittance. Toner for full color development is desired to have light transmittance in the binder resin so as not to impair the color development of other toner colors on paper. Therefore, it is sufficient that the binder resin of the toner has a conductivity within the above range and has a certain degree of light transmittance.
More than one type may be used.

Also, add 2f of binder resin! Even when used as a mixture of resins of the same or higher grade, the electrical conductivity of the mixed resin satisfies the above range.

The binder resin of the toner for full color development may be the same type as the binder resin of other toners used at the same time, or may be of a different type. However, if the resins are different, the electrical conductivity of both resins must satisfy the above range.

Further, in the present invention, it is desirable to use a zinc compound of salicylic acid as the charge control agent.

Conventionally, charge control agents have been used in toners to control the state of charge, and in particular, negative charge control agents have been widely used. However, among the conventionally known charge control agents,
It not only changes the amount of charge of the toner, but also significantly changes other electrical properties such as conductivity, and if such a charge control agent is used in the toner, problems similar to those described above may occur. However, when a zinc compound of salicylic acid is used in combination with the above-mentioned binder resin, it is not only possible to control the charging property, which is the original function, but also to suppress changes in other electrical properties of the toner. At the same time, this state can be maintained for a long period of time, and it can be fully used as a toner for full color development. The zinc compound of salicylic acid may be a salt or a complex compound, and is preferably contained in an amount of 1.0 to 5.0% by weight, particularly 1.5 to 4.0% by weight based on the resin. .

One of the features of the present invention is that a copper phthalocyan pigment is used as the cyan colorant. Among conventional cyan colorants, some affect the charge control agent, or the combination with the binder resin and the charge control agent causes the toner color to lack sharpness.

However, the copper phthalocyanine pigment does not significantly affect the binder resin and charge control agent, and the color tone is not impaired by these. Therefore, the copper phthalocyanine pigment can be contained in the toner while effectively maintaining the aforementioned conductivity and charging properties, thereby providing a cyan toner suitable for full color development.

Another feature of the present invention is that a quinacridone pigment is used as the magenta colorant.

Among conventional magenta colorants, when combined with a binder resin and a charge control agent, the toner color may lack sharpness or the hue may shift.

However, the quinacridone pigment does not have much influence on the binder resin and the charge control agent, and the color tone is not impaired by these, and in particular, no change in color or hue is observed. Therefore, the quinacridone pigment can be contained in the toner while effectively maintaining the aforementioned conductivity and charging properties, providing a magenta toner suitable for full color development.

Furthermore, one of the features of the present invention is that a benzidine pigment is used as a yellow colorant. Among conventional yellow colorants, when the colored resin and charge control agent are combined, the toner color lacks sharpness;
Some may be found that affect charge control agents.

However, the benzidine pigment does not affect the binder resin and charge control agent, and the color tone is not inhibited by these. Therefore, the benzidine pigment is contained in the toner while effectively maintaining the aforementioned conductivity and charging properties, thereby providing a yellow toner suitable for full color development.

[Actual A mode The present invention will be explained in detail below.

The toner of the present invention is mainly used in combination with other toners of different colors. That is, the target is toner that constitutes the basic color in full-color development. There are four main types of basic full-color toner: magenta, cyan, yellow, and black. In full-color development, these toners are sequentially superimposed and developed to reproduce the tonal image quality of the original.

These toners contain a colorant and a charge control agent in a binder resin, and further contain or are added with well-known toner compounding agents.

Binder Resin As mentioned above, the binder resin of the present invention has an N conductivity of 1 and OX
10-' to 5. It is important to satisfy the range of OX 10-' (s/cffl), in particular: 1. OX1
It is desirable to satisfy the range of 0-9 to 3.0×1O-9 (s/cm). In addition, the binder resin is preferably one with excellent light transmittance, and examples of the resin having such characteristics include one selected from polyester, polystyrene, acrylic, polyether, polyamide, olefin, etc.
More than one type can be selected or used in combination.

As a specific polyester resin, the acid component thereof is an aromatic dicarboxylic acid, a fatty acid, or the like. More specific acid components include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, etc., and terephthalic acid is mainly used. Examples of the diol component include ethylene glycol, propylene glycol, diethylene glycol, butanediol, cyclohexane dimetatool, hexylene glycol, triethylene glycol, glycerol, mannitol, and pentaerythol.

Specific styrene-based resins include monomers such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o-, m-, p-chlorosdecyne, ethylstyrene, divinylstyrene, etc. alone or in combination. A polymerized product is used.

Examples of acrylic resins include ethyl acrylate,
Polymers of methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, acrylic acid, methacrylic acid, etc. may be used alone or in combination. In addition to those mentioned above, ethylenically unsaturated carboxylic acids and their anhydrides, such as maleic anhydride, fumaric acid, maleic acid, crotonic acid, and itaconic acid, can also be used.

Specific vinyl ether resins include vinyl-n-
Butyl ether, vinyl phenyl ether, vinyl cyclohexacyl ether, etc. are used.

Specific examples of polyamide-based resins include well-known resins consisting of diamines and dicarboxylic acids, and nylon 6 polymerized from lactam-based resins.

Specific olefin resins include ethylene, propylene, butene-1, pentene-1, methylpentene-1
etc.

Some of the above resins can be used alone, or a binder resin can be obtained by combining resins of 2 f1 or more and mixing the resins so as to have the above-mentioned conductivity.

In the present invention, it is particularly preferable to use polyester resin in terms of conductivity, light transmittance, and viscosity characteristics.

Colorant The colorant to be contained in the colored resin is a known colorant that has been conventionally used in this field. Furthermore, colorants can be broadly classified into cyan, magenta, yellow, and black pigments.

Next, specific colorants will be shown.

Colorants for magenta include red iron, cadmium red, red lead, mercury cadmium sulfide, permanent red 4R, permanent red FNG1, resol red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, and rhodamine. Rake, brilliant cardin 3
B. Spironred. Furthermore, purple-based manganese purple, Fast Violet B1 Methyl Violet Lake, and orange-based red yellow lead, molybdenum orange, permanent orange GTR, pyrazolo orange, palkan orange, inthethrene brilliant orange RK, benzidine orange G1 indus Examples include Len Brilliant Orange GK.

Further, as the magenta colorant, it is desirable to use a quinacridone pigment in the binder resin in order to fully achieve the above object.

Typical examples of quinacridone pigments include the following general formula: The following compounds are mentioned.

Specifically, C,1, Pigment Red 122, C,I.

pigment violet, etc.

Examples of the cyan colorant include navy blue, cobalt pull, alkali blue lake, phthalocyanine pull, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky pull, and industhrene blue BC.

Further, as the cyan colorant, it is desirable to use a copper phthalocyanine pigment in the binder resin in order to fully achieve the above object. Copper phthalocyanine is represented by the following formula, and the benzene nucleus in the structural formula may be substituted with alkyl or halogen.

Specific examples of copper phthalocyanine pigments include phthalocyanine blue, heliodan blue 01 fast sky blue, and the like.

Colorants for yellow include yellow lead, zinc yellow, cadmium yellow, navel yellow, and naphthol yellow S.
1 Hansa Yellow G1 Hansa Yellow 10G1 Benzidine Yellow G1 Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NGO, Tartrazine Lake, and the like.

In particular, as the yellow colorant, it is desirable to use a benzidine pigment in the binder resin in order to fully achieve the above object. Specific examples of benzidine pigments include Benzidine Yellow G and Benzidine Yellow G.
Examples include R.

Examples of the black colorant include carbon black, lamp black, and aniline black.

The mixing ratio of these colorants and fixing resin is 1:100 to 3
0:100, especially 3:100 to 20:10G
used in a weight ratio of

Charge control agent The binder resin may contain a charge control agent for controlling the charging of the toner. Examples of charge control agents include oil-soluble dyes such as nigrosine base (CI 50415) oil black (C126150) and Subiron black, naphthenic acid metal salts, metal soaps, metal-containing azo dyes,
Pyrimidine compounds, metal compounds of alkylsalicylic acids are used.

In particular, as the charge control agent, salts of salicylic acid and zinc or zinc complex compounds, and salts of alkyl salicylic acid and zinc or zinc complex compounds are desirable. These charge control agents are preferably contained in an amount of 1.0 to 5.0% by weight based on the binder resin.

The full-color toner formed from the above components preferably has a particle size in the range of 5 to 20 μm, particularly 8 to 15 μm in volume-based median diameter measured with a Coulter counter, and the particle shape is melt-kneaded.・It may be an amorphous one manufactured by pulverization or a spherical one manufactured by dispersion or suspension polymerization. Also, the surface of the toner is sprinkled with hydrophobic silica particles to improve its fluidity. You may let them.

When the above toner is mixed with a magnetic carrier and used as a two-component developer, a known magnetic carrier used in this field can be used, but it is usually preferable to use ferrite particles that can form a soft magnetic brush. preferable.

[Effects of the Invention] According to the present invention, the electrical conductivity is 1. OX 1G-' to 5.
By using a resin that satisfies the Ox 10-” (s/ca+) range as the binder resin for full-color toner,
Differences in electrical properties between toners used in layers can be reduced. Such a reduction in the difference in electrical properties allows the development conditions for each toner to be substantially constant during full color development. Furthermore, variations in the amount of each toner transferred can be reduced, and full-color toner with excellent image reproducibility can be provided.

An experimental example is shown below.

(Experimental Example 1) Experimental Example 1-1 Ioo parts by weight of polyester resin with an electrical conductivity of 1.5x 1O-9s/cm was used as the binder resin, 5 parts by weight of carbon black was used as the colorant, and salicylic acid was used as the charge control agent. Using 2 parts by weight of the zinc complex, these components were melt-kneaded, cooled, pulverized, and classified in a conventional manner to prepare a toner having an average particle size of 10 μm. The conductivity of this toner was 1.8x 1O-9s/cm.

Furthermore, in the above formulation, the colorants were changed to 5 parts by weight of a copper phthalocyanine pigment, 5 parts by weight of a quinacridone pigment, and 3.5 parts by weight of a benzidine pigment to create a cyan toner.
A magenta toner and a yellow toner were created respectively. These toner conductivities are 1.5xlO-', respectively.
It was 1.6 x lO-9,1.5 x 10-9 s/cm.

Then, these toners and a known magnetic ferrite carrier are mixed to form a two-component developer, and using a full-color electrophotographic copying machine that performs image exposure with a semiconductor laser, 20% of each color toner is used as a document (image area 20%: A4 ), and the density and vividness (stabilization of hue) of full-color images were evaluated when a color photographic original was used. Incidentally, the development conditions and transfer conditions were performed within the following ranges.

・Development conditions Photoconductor drum: Organic photoconductor for negative charging, photoconductor surface potential knee 700 to -850V, development bias potential: DC bias potential knee 500 to -650V: AC bias potential (frequency 1 kHz) -t5o to - 650V, developing sleeve circumferential speed/photosensitive drum circumferential speed = 2.5 to 4.0°・Transfer conditions Static elimination charger: -5kV to +500V
(2k) lz), transfer charger = 1st to 3rd color 5.
5-6.2kV.

4th color 6.0-6.5 kV.

Experimental Example 1-2 Using 100 parts by weight of a mixture of polymethyl methacrylate (MMA) and polyethylene acrylate (EA) with a conductivity of 2.7 x 10-'' s/cm as a binder resin,
Other formulations were the same as in Experimental Example 1-1 to prepare black toner, cyan toner, magenta toner, and yellow toner, and full color development was performed. The conductivity of these black toner, cyan toner, magenta toner, and yellow toner is 2.9X 10", respectively.
2.7X 10-', 2.6X10-9. 2.6x
It was 10-'s/cm.

Experimental Example 1-3 A toner was prepared in the same manner as in Experimental Example 1-1, except that a polyester resin with an electrical conductivity of 3.2 x 10-'' s/cm was used as the binder resin, and full color development was performed in the same manner. The conductivity of each of these black toner, cyan toner, magenta toner, and yellow toner was 1.2.
xlO-', 3.1xlO-", 3.2x10-
”s/cm.

Experimental Example 1-4 A toner was prepared in the same manner as in Experimental Example 1-1, except that polyester with an electrical conductivity of 8.9 x 10-'' s/cm was used as the binder resin, and full color development was performed in the same manner. The conductivity of these black toner, cyan toner, magenta toner, and yellow toner is 3.5x 1.
0-9. 8.8x 10-”.8.9x10”, 8
．． 7×10-”, s/cm.

Experimental Example 1-5 A toner was prepared in the same manner as in Experimental Example 1-1, except that polyester with an electrical conductivity of 5.8 x 10-'' s/cm was used as the binder resin, and full color development was performed in the same manner. The electrical conductivity of these black toner, cyan toner, magenta toner, and yellow toner is 6.Ox 1.
0-95.9x 10-95゜8x10-", 5.8
xlO-9s/cm.

Table 1 shows the results.

When using the toners of Experimental Examples 1-1 and 1-2, the amount of developed toner and transfer efficiency of each color toner are similar, and when full-color development is performed by overlapping, the outputted full-color image is vivid and can be printed on the original. It was faithful. On the other hand, in Experimental Examples 1-3, 1-4 and t-S toners, the amount of developing toner and transfer efficiency of each color toner were different, and the output full-color image could not faithfully reproduce the original and was vivid. It lacked quality.

(Experimental Example 2) Experimental Example 2-1 A toner was prepared in the same manner as in Experimental Example 1-1, except that polyester with an electrical conductivity of 1.6 x 10-" s/cm was used as the binder resin, and Full-color development was performed.The conductivity of each of these black toner, cyan toner, magenta toner, and yellow toner is 1.8X.
10-', 1.6X 10-'', 1.6X10
-', 1.5x 1O-9s/cm. Then, a stiff toner and a known magnetic ferrite carrier are mixed to form a two-component developer, and full-color development is carried out using a full-color electrophotographic copying machine that performs image exposure using a semiconductor laser in the same manner as in Experimental Example 1. I looked at the change in image quality for 1000 images.

Experimental Example 2-2 The same binder resin as in Experimental Example 2-1 was used, the same charge control agent as in Experimental Example 2-1 was used for the black toner and the yellow toner, and the cyan toner and magenta toner were A toner was prepared in the same manner except that 2 parts by weight of the metal-containing monoazo dye was used.

The conductivity of these black toner, cyan toner, magenta toner, and yellow toner is 1.8X.
10-92.2X 10-92.1X 10-91.
It was 5 x 1O-9s/cal. Image formation was performed in the same manner.

The results are shown in Table 2.

From Table 2, the toner using the zinc complex of salicylic acid is
It can be seen that the developability and transferability do not change even during continuous copying, and a good image is stably maintained.

On the other hand, it can be seen that when a monoazo metal dye is used, the developability and transferability of the toner fluctuate, resulting in a decrease in image reproducibility.

Table 2 (Experimental Example 3) Experimental Example 3-1 5 parts by weight of a quinacridone pigment as a coloring agent and a charge control agent to 100 parts by weight of polyester with a conductivity of 1.6x 1O-9s/cm as a binder resin. Using 2 parts by weight of a zinc complex compound of salicylic acid, melt-kneading, cooling, pulverization, and classification were performed in a conventional manner to obtain a toner having an average particle size of 8.5 μm. The conductivity of this toner is 1.6x 10-
'(s/cm).

Furthermore, a black toner, a cyan toner, and a yellow toner were prepared in the same manner except that the colorants in the above formulation were changed to 5 parts by weight of carbon black, 5 parts by weight of copper phthalocyanine pigment, and 4 parts by weight of benzidine pigment. . The conductivity of these toners is 1.8X 10
-', 1.7x 10-91.6x 1O-9(s/c
m). Then, these toners and a known magnetic ferrite carrier are mixed to form a component developer, and full-color development is carried out using a full-color electrophotographic copying machine that performs image exposure using a semiconductor laser in the same manner as in Experimental Example 1.
I looked at the change in image quality for 1000 images.

Experimental Example 3-2 Zinc complexation of 5 parts by weight of a quinacridone pigment as a coloring agent and salicylic acid as a charge control agent to 100 parts by weight of a polyester resin with an electrical conductivity of 4.2 x 10-'s/cm as a binder resin. Using 2 parts by weight of the compound, melt-kneading, cooling, pulverizing, and classifying were performed in a conventional manner to obtain an average particle size of 9.0μ.
m toner was obtained. The conductivity of this toner is 4.2x 1
0-'(s/cI11).

Furthermore, in the above formulation, the colorants were changed to 5 parts by weight of carbon black, 5 parts by weight of copper phthalocyanine pigment, and 5 parts by weight of benzidine pigment, and black toner, cyan toner, and yellow toner were prepared in the same manner as above. Created with. The conductivity of these toners is 4.2x 10-';
4.1x 10-"4.2x10-'(s/c
m). Thereafter, image formation was performed in the same manner as in Experimental Example 3-1.

Experimental Example 3-3 Conductivity of binder resin is 8.9x 10-” s/cm
Various toners were produced in the same manner as in Experimental Example 3-3 except that the polyester resin was used.

The conductivity of magenta toner, black toner, cyan toner, and yellow toner is 9.3X 10-
”, 9.6×10−”, 9.2×10−” and 9.3×10−”s/cm.

Full color development was performed in the same manner as in Experimental Example 3-1.

Experimental Example 3-4 A magenta toner was produced in the same manner as in Experimental Example 3-1, using polyester with a conductivity of 1.3×10-”s/cm as the binder resin. However, a magenta toner containing a charge control agent was used. The metal azo dye was 2 parts by weight.The conductivity of the magenta toner was 9.
．． 8x 1G-” s/cm, the particle size is 8.5μm
Met.

Furthermore, in the above formulation, the colorant was changed to 5 parts by weight of carbon black, 5 parts by weight of copper phthalocyanine pigment, and 5 parts by weight of benzidine pigment, and the charge control agent in the cyan toner and yellow toner was changed to a zinc salicylate compound. A black toner, a cyan toner, and a yellow toner were prepared in the same manner except for the following. The conductivities of these toners are 9.8xlO-', 1.2xlO-',
IJxlO-9 (s/cm).

Experimental Example 3-5 4 parts by weight of a quinacridone pigment as a coloring agent and 2 parts by weight of a metal-containing azo dye as a charge control agent were added to 100 parts by weight of a polyester resin having an electrical conductivity of 5.5 x 10-'' s/cm as a binder resin. A toner with an average particle size of 8.5 μm was obtained by melt-kneading, cooling, pulverizing, and classifying using parts by weight in a conventional manner.The electrical conductivity of this toner was 5.5 x 10-" (
s/cm).

Furthermore, in the above formulation, the conductivity of the binder resin is 3.9 x
The colorant was changed to 5 parts by weight of carbon black, 5 parts by weight of copper phthalocyanine pigment, and 5 parts by weight of benzidine pigment, and 2 parts by weight of a zinc complex compound of salicylic acid was added as a charge control agent. A black toner, a cyan toner, and a yellow toner were prepared in the same manner. The conductivity of each toner is 4. OX10
-', 3.9x 10-", 3.8x 10-'
(s/cm). Then, these toners and a known magnetic ferrite carrier are mixed to form a two-component developer,
Full-color development was performed using a full-color electrophotographic copying machine that performs image exposure using a semiconductor laser.

(Experimental Example 4) Experimental Example 4-1 100 parts by weight of polyester having an electrical conductivity of 1.5 x 10-'s/cm as a binder resin, 5 parts by weight of copper phthalocyanine pigment as a coloring agent, and 5 parts by weight of a copper phthalocyanine pigment as a charge control agent. Using 2 parts by weight of a zinc complex compound of salicylic acid, melt-kneading, cooling, pulverizing, and classifying were performed in a conventional manner to obtain an average particle size of 8.5μ.
m toner was obtained. The conductivity of this toner is 1.6X
10-' (s/cm).

Furthermore, black toner, magenta toner, and yellow toner were prepared in the same manner except that the colorants in the above formulation were changed to 5 parts by weight of carbon black, 5 parts by weight of quinacridone pigment, and 4 parts by weight of benzidine pigment. . The conductivity of these toners is 1.7X 10-
', 1.6X 10-'1.6x 10-'' (s/cm
)Met. Then, these toners and a known magnetic ferrite carrier are mixed to form a two-component developer, and full-color development is carried out using a full-color electrophotographic copying machine that performs image exposure using a semiconductor laser in the same manner as in the experimental example.
I saw the image quality change for 000 images.

Experimental example 4-2 Conductivity of binder resin is 5.5x 1G-”s/ca+
To 100 parts by weight of the polyester resin, 5 parts by weight of copper phthalocyanine pigment as a coloring agent and 2 parts by weight of a metal-containing azo dye as a charge control agent were melt-kneaded, cooled, pulverized, and classified in a conventional manner to obtain an average A toner having a particle size of 8.5 μm was obtained. The conductivity of this toner is 5.5 x 1G
-' (s/cm).

Furthermore, 100 parts by weight of a polyester resin having an electrical conductivity of 3.9 x 10"" (s/cm) was used, and as colorants, 5 parts by weight of carbon black, 5 parts by weight of benzidine pigment, and 5 parts by weight of quinacridone pigment were added. A black toner, a magenta toner, and a yellow toner were prepared in the same manner using 2 parts by weight of a zinc complex compound of salicylic acid as a charge control agent.

The conductivity of each toner is 4. OX 10-”,
3.8x10-9. 3.8x 10-” (s/cm)
Met.

Table 4 below shows the results of full color development.

(Experimental Example 5) Experimental Example 5-1 3.5 parts by weight of a benzidine pigment as a coloring agent and a charge control agent to 100 parts by weight of a polyester resin with an electrical conductivity of 3.8x 1O-9s/cm as a binder resin. Using 2 parts by weight of a zinc complex compound of salicylic acid, melt-kneading, cooling, pulverization, and classification were carried out in a conventional manner to obtain an average particle size of 9.0.
A μm toner was obtained. The conductivity of this toner is 3.9X
10-'' (s/cm).

Furthermore, as a binder resin, the electrical conductivity is 3.5x 1O-9s/
cm of polyester resin, 5 parts by weight of carbon black as a coloring agent, 5 parts by weight of a copper phthalocyanine pigment, 5 parts by weight of a quinacridone pigment, and 2 parts by weight of a zinc complex compound of salicylic acid as a charge control agent. A black toner, a cyan toner, and a magenta toner were prepared in the same manner as above. The conductivity of these toners is 3.7X10-", 3.8 xl
O-', 3.8X10-9 (s/cm),
Then, these toners and a known magnetic ferrite carrier were mixed to form a two-component developer, and full-color development was carried out in the same manner as in Experimental Example 1 to observe variations in image quality over 1 to 1000 sheets.

Experimental Example 5-2 Conductivity of binder resin is 5.5 x 1G-'s/cm
To 100 parts by weight of the polyester resin, 4 parts by weight of a benzidine pigment as a coloring agent and 2 parts by weight of a metal-containing azo dye as a charge control agent were melt-kneaded, cooled, pulverized, and classified in a conventional manner to obtain an average particle size. A toner having a diameter of 8.5 μm was obtained. The conductivity of this toner is 5.6 x 10-'(s
/cm).

Furthermore, in the above formulation, the colorant was changed to 5 parts by weight of carbon black, 5 parts by weight of copper phthalocyanine pigment, and 5 parts by weight of quinacridone pigment, and 2 parts by weight of zinc complex compound of salicylic acid was used as the charge control agent. A black toner, a cyan toner, and a magenta toner were created. The conductivity of each toner is 4. OX 10”
”, 3.9X 10-'3.8 X 10-'(s/c
m), and these toners and a known magnetic ferrite carrier were mixed to form a two-component developer, and Experimental Example 1
Full-color development was carried out using a full-color electrophotographic copying machine that performs image exposure using a semiconductor laser in the same manner as described above.

The following results are shown in Table-5.

[Brief explanation of drawings]

FIG. 1 is a principle diagram showing a developing section and a transfer section of an image forming apparatus for obtaining a full-color image.

Claims (4)

[Claims] (1) A full-color developing toner in which a coloring agent is contained in a binder resin and which is used in combination with another toner having a different color tone, wherein the conductivity of the binder resin is 1.0×1.
A toner that satisfies a range of 0^-^9 to 5.0 x 10^-^9 (s/cm). (2) The toner according to claim 1, further comprising a zinc compound of salicylic acid as a charge control agent. (3) The toner according to any one of claims 1 to 2, wherein the colorant is copper phthalocyanine. (4) The toner according to any one of claims 1 to 2, wherein the colorant is a benzidine pigment. (5) The toner according to any one of claims 1 to 2, wherein the colorant is a quinacridone pigment.