JPH08234490A - Toner for full-color development - Google Patents

Abstract

PURPOSE: To obtain a toner stably giving a satisfactory full-color image excellent in transparency, color reproducibility and light resistance. CONSTITUTION: In this toner used in a full-color image forming device in which development is carried out for every specified color with at least a cyan toner, a magenta toner and a yellow toner, polyester resin having 1-30mgKOH/g acid value, a number average mol.wt. Mn of 3,000-6,000, 50-70 deg.C glass transition temp. and 90-110 deg.C softening point is used as the resin binder of each of the cyan, magenta and yellow toners, and a cyan pigment, a magenta pigment and a yellow dye are used as colorants in the cyan, magenta and yellow toners, respectively. The ratio (Mw/Mn) of the wt. average mol.wt. Mw of the polyester resin to the number average mol.wt. Mn is 2-6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a full-color developing toner used in a full-color image forming apparatus such as a full-color copying machine or a full-color printer, and more particularly to a predetermined color using at least a cyan toner, a magenta toner and a yellow toner. The present invention relates to a full-color developing toner used in a full-color image forming apparatus that develops each time to form a full-color image.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic method has been used in which an electrostatic latent image formed on a photoconductor is developed with toner and the toner image is transferred onto a recording member such as recording paper to form an image. Image forming apparatuses such as copying machines, printers, and facsimiles are widely used. In recent years, full-color image forming apparatuses such as full-color copying machines and full-color printers that perform full-color image formation using toners of a plurality of colors have been developed. It came to be used.

There are various types of such full-color image forming apparatuses, and generally, a predetermined means such as a writing means for irradiating a charged photosensitive member with a light beam such as a laser is used. An electrostatic latent image corresponding to a color is formed, and a predetermined toner selected from magenta toner, cyan toner, yellow toner and, if necessary, black toner is supplied to the electrostatic latent image for development. The latent image forming step and the developing step are performed for each color, and these toner images are superposed to obtain a full-color image.

With respect to the full-color developing toner used for forming such a full-color image, it is possible to stably form a full-color image and to obtain a good full-color image having good durability. ,
In addition to being excellent in heat-resistant storage property, fixing property, light resistance, etc.,
The magenta toner, the cyan toner, and the yellow toner are required to have excellent light-transmitting properties and color-mixing properties in order to obtain a full-color image by superimposing these toner images.

Further, in the above-described full-color image forming apparatus, a full-color image may be formed on a transparent overhead projector sheet (hereinafter abbreviated as an OHP sheet) in addition to the recording paper which is generally used. When a full-color image is formed by superposing toner images of a plurality of colors on the OHP sheet as described above, each toner has a spectral reflectance corresponding to a desired color and As described above, when the toner images of the respective colors are superposed on each other, the above-mentioned respective color toners are required to have further excellent translucency so that the color of the toners located therebelow is not hidden by the toners located thereabove.

Here, various pigments and dyes have been conventionally used as colorants in the color toners including the magenta toner, the cyan toner and the yellow toner, but each has various drawbacks.

For example, when a pigment is used as a colorant in each of the above color toners, an image generally superior in heat resistance and light resistance is obtained as compared with the case where a dye is used.
When the toner image is formed on the OHP sheet, the projection image becomes dark and the saturation is reduced because the pigment is dispersed in the toner in a particle state. When the toner image is formed on the recording member, the spectral reflection characteristics deteriorate due to the light scattering in the pigment particles dispersed in the toner, and the color of the document is accurately corrected. There was a problem that it could not be reproduced.

On the other hand, when a dye is used as the colorant in each of the above color toners, the dye is generally present in a state of being dissolved in the binder resin, and therefore, compared with the case where the pigment is used, the translucency and Although images with excellent color saturation etc. can be obtained, heat resistance and light resistance are low, and even if images with excellent saturation are obtained, fading due to light occurs and good images are long-lasting. There is a problem that it cannot be maintained for a period of time, and because it has low heat resistance, the dye sublimes to contaminate the inside of the device when fixing the toner image, and the dye dissolves in the silicone oil used during fixing. There was also a problem such as doing.

[0009]

SUMMARY OF THE INVENTION The present invention is a full-color image forming apparatus for forming a full-color image by performing development for each predetermined color using at least cyan toner, magenta toner and yellow toner. It is an object of the present invention to solve the above problems in developing toner.

That is, according to the present invention, in the above-described full-color developing toner, at least a cyan toner, a magenta toner, and a yellow toner are used to form a full-color image in which the toner images are superposed. In addition, each toner has sufficient heat-resistant storage property and fixing property, and also has excellent translucency and color mixing property. Even when a toner image as described above is superposed on an OHP sheet to form a full-color image. It is an object of the present invention to provide a full-color developing toner that has sufficient translucency and does not cause a projected image to become dark or have a reduced saturation, and that a full-color image can be stably maintained for a long period of time. It is what

[0011]

In order to solve the above problems, the present invention develops a predetermined color for each color using at least cyan toner, magenta toner and yellow toner to form a full color image. In the full-color developing toner used in the full-color image forming apparatus, the binder resin in each of the cyan toner, the magenta toner and the yellow toner has an acid value of 1 to 30 mgKOH / g and a number average molecular weight Mn.
Is 3000 to 6000, the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is 2 to 6, the glass transition point is 50 to 70 ° C., and the softening point is 90 to 110 ° C. while using a polyester resin, A cyan pigment is used as the colorant in the cyan toner, a magenta pigment is used as the colorant in the magenta toner, and a yellow dye is used as the colorant in the yellow toner.

In the present invention, the acid value of the binder resin of each of the above toners is 0.1% bromthymol blue with respect to a solution prepared by dissolving 10 g of the resin weighed in 50 ml of toluene. Pre-standardized N / using a mixed indicator of phenol red
Titrate with 10 potassium hydroxide / alcohol solution,
The acid value was calculated from the consumption amount of N / 10 potassium hydroxide / alcohol by the following formula. Acid value = 5.61 (mg) × KOH
(Ml) x N / resin amount (mg)

The number average molecular weight Mn and the weight average molecular weight Mw of the binder resin of each toner are measured by gel permeation chromatography (JASCO Corporation: 807-IT type), and the column is 40. Keeping the temperature at ℃, flowing tetrahydrofuran as a carrier solvent at 1 kg / cm ² , dissolve 30 mg of the sample to be measured in 20 ml of tetrahydrofuran, and add 0.5 m of this solution.
g was introduced together with the above carrier solvent, and the value was calculated in terms of polystyrene.

The glass transition point of the binder resin of each toner is measured with a differential scanning calorimeter (DSC-200 manufactured by Seiko Denshi KK) to obtain a sample of 10 m.
Accurately weigh g, put it in an aluminum pan,
Alumina placed in an aluminum pan was used as a reference, and the temperature was raised from room temperature to 20
After raising the temperature to 0 ° C, cool it and raise the temperature at 10 ° C.
The temperature was measured at 20/120 ° C./min, and the shoulder value of the main endothermic peak in the range of 30-80 ° C. during this temperature rising process was taken as the glass transition point Tg.

Regarding the softening point of the binder resin of each toner, a flow tester (manufactured by Shimadzu Corporation:
CFT-500), 1.0 g of the sample to be measured is weighed, a 1.0 mm × 1.0 mm die is used, and the temperature rising rate is 3.0 ° C./min, the preheating time is 180 seconds, and the load is 30 kg.
The measurement was carried out by the above flow tester under the condition of the measurement temperature range of 60 to 140 ° C., and the temperature at which the above sample flowed out in half was defined as the softening point Tm.

In the full-color developing toner of the present invention, a polyester resin having an acid value of 1 to 30 mgKOH / g is used as the binder resin in each of the cyan, magenta and yellow color toners. Has an acid value of 30 mg KO
The use of one having a value higher than H / g impairs the environmental stability of the obtained toner, particularly the stability of the amount of charge with respect to humidity, while the use of one having an acid value of less than 1 mgKOH / g causes coloring of the binder resin. The dispersibility of the agent becomes poor, and the dispersion state of the colorant in each toner particle becomes non-uniform. As a result, the charge in each toner particle becomes non-uniform, and fogging easily occurs in the formed image. It is preferable to use a polyester resin having an acid value of 2 to 25 mgKOH / g.

The binder resin is a polyester resin having a number average molecular weight Mn of 3,000 to 6000. When the number average molecular weight Mn of less than 3,000 is used, the bending fixing property of the obtained toner is lowered. Then, when the recording member on which the full-color image is formed is bent, the toner in the image portion is easily peeled off to cause an image defect, while the number average molecular weight Mn is 60.
This is because the use of a polymer having a number average molecular weight of more than 00 lowers the heat melting property of the toner during fixing and lowers the fixing strength of these toners to the recording member, and is preferably a polyester having a number average molecular weight Mn of 3500 to 5500. Use resin.

Further, the polyester resin having the ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn of 2 to 6 is used as the binder resin when the resin having the ratio smaller than 2 is used. When an image is formed using this toner, high-temperature offset is likely to occur, while when the ratio is larger than 6, the sharp melt property at the time of fixing the toner is deteriorated and the toner is fixed. The translucency and color mixing of the toner in the image decrease,
This is because the color reproducibility is deteriorated and a good full-color image cannot be obtained, and this ratio (Mw / M
A polyester resin having n) of 2.5 to 5.5 is used.

Further, the polyester resin having a glass transition point Tg of 50 to 70 ° C. is used as the binder resin, and when a resin having a glass transition point Tg lower than 50 ° C. is used, the heat resistance of the obtained toner is high. The glass transition point Tg is 70 ° C. while the toner tends to agglomerate during storage.
If the higher one is used, the fixing strength of the obtained toner to the recording member is lowered, and the color mixing property of each toner is also lowered, the color reproducibility is deteriorated, and a good full color image cannot be obtained. Yes, it is preferable to use a polyester resin having a glass transition point Tg of 55 to 65 ° C.

The softening point Tm of 90 to 110 ° C. is used as the binder resin.
If m is lower than 90 ° C., high-temperature offset tends to occur when an image is formed using this toner, while if softening point Tm is higher than 110 ° C., meltability of this toner is high. The characteristics are lowered, the fixing strength to the recording member is lowered, and the translucency, color mixture and gloss of the toner in the fixed image are lowered,
This is because the color reproducibility is deteriorated and a good full-color image cannot be obtained, and the softening point Tm is preferably 90.
Use a polyester resin of ~ 105 ° C.

Here, as the polyester resin used as the binder resin in each of the above color toners,
The molecular weight, the glass transition point Tg, and the softening point Tm are in the above-mentioned ranges, so that a toner having sufficient sharp melt characteristics, translucency, color mixture, and the like, and having sufficient strength and heat resistance can be obtained. Therefore, it is preferable to use a polyester resin using etherified diphenols as the alcohol component and aromatic dicarboxylic acids as the acid component.

The etherified diphenols used for this polyester resin are, for example, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3).
-2,2-bis (4-hydroxyphenyl) propane,
Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-
Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane and the like can be used.

In order to adjust the glass transition point Tg and the softening point Tm of this polyester resin, an alcohol component other than the above etherified diphenols is used.
For example, ethylene glycol, diethylene glycol,
Diols such as triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol; sorbitol, 1,2,3,6-hexanetetrol, 1,
4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-
Butanetriol, 1,2,5-pentanetriol,
Add a small amount of polyhydric alcohol such as glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene. Good.

On the other hand, as the above-mentioned aromatic dicarboxylic acids, for example, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, their acid anhydrides or their lower alkyl esters, etc. can be used.

In order to adjust the glass transition point Tg and softening point Tm of this polyester resin, in addition to the above aromatic dicarboxylic acids, for example, fumaric acid, maleic acid, succinic acid, alkyl having 4 to 18 carbon atoms. Alternatively, a small amount of an aliphatic dicarboxylic acid such as alkenylsuccinic acid or an acid anhydride thereof or an aliphatic dicarboxylic acid such as a lower alkyl ester may be added.

Further, in order to adjust the acid value of the polyester resin and to improve the resin strength thereof, in addition to the above, for example, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2 , 5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
1,2,4-naphthalene tricarboxylic acid, 1,2,4-
Butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1, Polyvalent carboxylic acids such as 2,7,8-octanetetracarboxylic acid, pyromellitic acid, their anhydrides or lower alkyl esters thereof may be added in a small amount within a range that does not impair the translucency of the toner. .

In the present invention, cyan and magenta pigments are used as the colorants in the cyan toner and magenta toner, while the yellow dye is used as the colorant in the yellow toner instead of the yellow pigment.
Generally, the particle size of the yellow pigment is larger than that of the cyan pigment or magenta pigment, and in the yellow toner in which this yellow pigment is dispersed in the binder resin, the light scattering on the surface of the yellow pigment is larger than that of the cyan toner or magenta toner. However, when the full color image is formed using this yellow toner, the spectral reflection characteristics deteriorate due to light scattering in the yellow pigment and the color of the original is reproduced accurately. This is because the projection image becomes dark and the saturation becomes low especially when a full-color image is formed on the OHP sheet. Also, the colors of things in the world are yellow, cyan,
When reproducing using magenta, since yellow is generally used frequently, the characteristics such as translucency of the yellow toner have a great influence on the obtained full-color image, and the above problems are remarkable. become.

Therefore, in the present invention, the yellow dye is used as the colorant in the yellow toner, and when the yellow dye is used as the colorant in this manner, the yellow dye is dissolved in the binder resin to form a uniform state. A yellow toner that is present and has excellent transparency can be obtained, and when a full-color image is formed, it exhibits excellent color reproducibility in combination with a cyan toner or a magenta toner, and also has an excellent light-transmitting property. A full-color image can be obtained.

The amount of the yellow dye contained in the yellow toner is generally 100 parts by weight of the binder resin so that the yellow dye is sufficiently dissolved in the binder resin and exhibits a sufficient color. 1 to 6 parts by weight, preferably 2 to 5 parts by weight.

On the other hand, when a pigment is used as a colorant in cyan toner or magenta toner, the particle size of the cyan pigment or magenta pigment is smaller than that of the yellow pigment, and sufficient translucency and color reproducibility can be secured. This is because it is possible to obtain a toner having excellent heat resistance and light resistance as compared with the case where a dye is used.

The amounts of the cyan pigment and magenta pigment contained in the cyan toner and magenta toner are as follows.
In order for each toner to have sufficient translucency and sufficient color, and to allow each pigment to be well dispersed in the binder resin, generally 1 to 6 parts by weight, preferably 100 parts by weight of the binder resin, is preferable. Is contained in an amount of 2 to 5 parts by weight.

Here, as the magenta pigment, for example,
C. I. Pigment Red 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 1
6, 17, 18, 19, 21, 22, 23, 30, 3
1, 32, 37, 38, 39, 40, 41, 48, 4
9, 50, 51, 52, 53, 54, 55, 57, 5
8, 60, 63, 64, 68, 81, 83, 87, 8
8, 89, 90, 112, 114, 122, 123, 1
63, 184, 202, 206, 207, 209 and the like can be used. Particularly, in terms of color reproducibility and translucency,
C. I. Pigment Red 122, 202, 206, 2
Quinacridone pigments such as 07 and 209, and C.I. I. Pigment Red 64, 184 and other azo pigments are preferably used.

As the cyan pigment, for example, C.I.
I. Pigment Blue 2, 3, 15, 16, 17 and the like can be used. Particularly, from the viewpoint of color reproducibility and translucency, C.I. I. Pigment Blue 15, 16 and the like are preferably used.

As the yellow dye, for example,
C. I. Solvent Yellow 2, 6, 14, 15, 1
6, 19, 21, 33, 56, 61, 77, 79, 8
0, 93, 162 and the like can be used, and particularly light resistance,
From the viewpoint of enhancing heat resistance, oil solubility resistance, etc., C.I.
I. It is preferable to use Solvent Yellow 162.

In the cyan toner and the magenta toner described above, in order to uniformly disperse the respective pigments in the binder resin, the dispersibility of the pigment used is improved by a flushing treatment, and the pigment is used. It is preferable to perform a masterbatch treatment in which a masterbatch in which is dispersed in a binder resin at a high concentration is manufactured in advance, the masterbatch is melt-kneaded with the binder resin, and the pigment is dispersed in the binder resin. In addition,
With respect to the yellow toner, a dye is used as a colorant, and since this dye has solubility in the binder resin, it is not necessary to perform the above treatment.

Further, in the present invention, in addition to the binder resin and the colorant as described above, a charge control agent, a post-treatment agent or the like for adjusting the chargeability of the toner or improving the fluidity of the toner. Various additives can be added.

Here, as the charge control agent, a colorless, white or light color charge control agent is preferably used so as not to adversely affect the color tone and light transmittance of toners of various colors. A charge control agent such as a salicylic acid metal complex of a salicylic acid derivative and a metal such as zinc, a calixarene compound, a boron compound, or a fluorine-containing quaternary ammonium salt compound can be used.

As the salicylic acid metal complex, for example, those described in JP-A-53-127726 and JP-A-62-145255 can be used as the calixarene-based compound. 2-2
Examples of the boron compound include those described in, for example, JP-A No. 2-221967, and examples of the fluorine-containing quaternary ammonium salt compound include those described in JP-A No. Those described in JP-A-1162, etc. can be used alone or in combination. Further, in order to adjust the charge amount of the toner and improve the rising property of the charge, a fluorine-containing quaternary ammonium salt compound is used in combination with a charge control agent such as a salicylic acid metal complex or a calixarene compound. It is also possible.

Here, when the charge control agent as described above is added, a binder is usually used so that the toner has proper chargeability and the charge control agent is well bound to the binder resin. 0.1 to 10 parts by weight, preferably 0.5 to 5.0, relative to 100 parts by weight of the resin.
Part by weight is added.

As the post-treatment agent, for example, silica, alumina, titania, tin oxide, zirconium oxide or the like can be used alone or in combination of two or more kinds. It is preferable to use those that have been subjected to a hydrophobizing treatment in order to enhance stability, and as the hydrophobizing agent, various coupling agents such as silane-based, titanate-based, aluminum-based, zircoaluminate-based, and silicone oil, etc. Can be used.
In particular, as the above-mentioned post-treatment agent, it is preferable to use hydrophobic silica and hydrophobic titania in combination, and hydrophobic silica and hydrophobic alumina in combination, from the viewpoints of fluidity of the toner and environmental stability against charging. Regarding the amount of the post-treatment agent added, 0.2 to 3.0% by weight is added to the toner in order to increase the fluidity of the toner and prevent the post-treatment agent from being released and adversely affecting the toner. It is preferable to do so.

In producing the full-color developing toner of the present invention, it is preferable to produce the toner by a kneading / pulverizing method from the viewpoints of reducing the production cost and improving the production stability.

Here, when the toner is produced by the kneading and pulverizing method, the above polyester resin, the colorant and, if necessary, the above various additives are added and mixed with a mixer such as a Henschel mixer. After the mixture is melted and kneaded, the kneaded product is cooled, then coarsely pulverized, and the coarsely pulverized particles are finely pulverized, and the obtained finely pulverized particles are classified to obtain a toner. Particularly, for the cyan toner and the magenta toner using a pigment as the colorant, it is preferable to perform the master batch process as described above. Further, when the toner is manufactured in this way, from the viewpoint of enhancing the reproducibility of a highly delicate image,
It is preferable to adjust the volume average particle diameter of the toner to be in the range of 5 to 10 μm.

Further, each toner in the present invention can be used as a two-component developing toner used together with a carrier or as a one-component developing toner not using a carrier.

Here, as the carrier used in combination with the toner in the present invention, a known carrier which has been generally used as a carrier for two-component development can be used, and examples thereof include iron and ferrite. It is possible to use a carrier composed of magnetic particles, a resin-coated carrier prepared by coating such magnetic particles with a resin, a binder-type carrier prepared by dispersing magnetic fine powder in a binder resin, and the like.

Among these carriers, a silicone resin, a copolymer resin of organopolysiloxane and vinyl monomer, or a polyester resin is used as a coating resin from the viewpoint of suppressing spent formation by toner. It is preferable to use a resin-coated carrier or a binder-type carrier that uses a polyester resin as a binder resin. From the viewpoint of durability, environmental stability and spent resistance, organopolysiloxane and vinyl monomer are used. It is preferable to use a resin-coated carrier coated with a resin obtained by reacting a copolymer resin with the above with isocyanate. Regarding the average particle size of the carrier used, it is preferable to use an average particle size of 30 to 60 μm in order to obtain high image quality and prevent fogging by the carrier.

In the present invention, at least the cyan toner, the magenta toner, and the yellow toner may be used as described above, but the black toner may be further used.

Here, in this black toner,
Although the same binder resin as each of the above color toners can be used, it is preferable to use one having a higher durability than each of the above full color toners in consideration of forming a monochrome image alone.

As the colorant for the black toner, a mixture of a cyan pigment, a magenta pigment and a yellow pigment can be used, but in this case, the content of the colorant is large and the cost is high. Adhesion and toner fixability are also adversely affected, and when a monochrome image is further formed, the blackness thereof is insufficient, and the reproducibility of character images and the like may decrease. Use carbon black.

And as this carbon black,
From the viewpoint of increasing the blackness, the average primary particle size is 15 to 80 nm.
It is preferable to use RAVEN1060 having an average primary particle size of 28 nm (manufactured by Columbia Carbon Co., Ltd.) and RAVEN500 having an average primary particle size of 56 nm.
(Manufactured by Columbia Carbon Co., Ltd.), average primary particle size is 47 nm
MA # 25 (manufactured by Mitsubishi Chemical Corporation), average primary particle size is 68n
m RAVEN420 (manufactured by Columbia Carbon Co.) or the like can be used. Further, the amount of such carbon black to be added is 2 to 8 parts by weight, preferably 100 parts by weight of the binder resin, in order to have sufficient blackness and hiding power and to exhibit excellent fixability. Is contained in an amount of 2 to 6 parts by weight.

Also in the case of this black toner, as in the case of each color toner described above, in addition to the binder resin and the colorant, in order to adjust the chargeability of the toner and to improve the fluidity of the toner. Various additives such as a charge control agent and a post-treatment agent can be added. In the case of a black toner, it is less necessary to consider the influence on the color, and therefore, a charge control agent or the like having a color such as black can be used.

The full-color developing toner according to the present invention forms an electrostatic latent image corresponding to a predetermined color on the uniformly charged photoconductor by a writing means such as irradiating a light beam. The latent image is developed with a predetermined toner selected from magenta toner, cyan toner, yellow toner and black toner as required, and each step of transferring this toner image onto an intermediate transfer member is sequentially performed for each color. After that, an image forming apparatus for transferring and fixing the toner image superposed on the intermediate transfer body onto the recording member, or an electrostatic image corresponding to a predetermined color formed on the photosensitive body in the same manner as the above apparatus. The latent image was developed with a predetermined toner selected from magenta toner, cyan toner, yellow toner and, if necessary, black toner, and this toner image was held on the intermediate transfer member. An image forming apparatus for fixing the toner image superimposed on the recording member after sequentially performing the process of transferring to the recording member for each color, or a predetermined color formed on the photoconductor in the same manner as the above apparatus. The electrostatic latent image corresponding to is developed with a predetermined toner selected from magenta toner, cyan toner, yellow toner and, if necessary, black toner, and the latent image forming step and the developing step are performed for each color to be exposed. Form a superposed toner image on the body,
It can be used in an image forming apparatus or the like that transfers and fixes this toner image on a recording member.

[0052]

In the full-color developing toner of the present invention, the acid value, the number average molecular weight Mn, the weight average molecular weight Mw and the number average molecular weight Mn are contained in the binder resin of each color toner of cyan toner, magenta toner and yellow toner.
Since a polyester resin having a ratio (Mw / Mn), a glass transition point and a softening point satisfying the above conditions is used, each toner exhibits sufficient heat resistant storage property, fixing property, light transmitting property and color mixing property. become.

Further, in the present invention, since the yellow dye is used as the colorant in the yellow toner and the cyan and magenta pigments are used as the colorants in the cyan toner and the magenta toner, respectively, the light transmitting property and the color mixing property are excellent. , When a full-color image is formed on an OHP sheet, a good full-color image can be obtained without causing the projected image to be dark and having low saturation, and the color of the document cannot be accurately reproduced. .

[0054]

EXAMPLES The present invention will be specifically described below with reference to examples, but the invention is not limited thereto.

Here, as binder resins in the toners of Examples and Comparative Examples, polyester resins A to F produced as described below were used.

(Polyester Resins A to E) In producing these polyester resins A to E, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene ( 2.
0) -2,2-bis (4-hydroxyphenyl) propane, fumaric acid, and terephthalic acid in molar ratios of 5.0: 5.0: 5.0: 4.0, respectively. And put these in a 2 liter, 4-necked flask,
A reflux condenser, a water separator, a nitrogen gas introducing pipe, a thermometer, and a stirrer were attached to this four-necked flask, and while heating and stirring them while introducing nitrogen into the flask from the above-mentioned nitrogen gas introducing pipe. I was allowed to react.

Then, the reaction state was traced while measuring the acid value during this reaction, and when the predetermined acid value was reached, the reaction was terminated to obtain polyester resins A to E shown in Table 1.

(Polyester Resin F) In producing the polyester resin F, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) is used.
Propane and polyoxyethylene (2.0) -2,2-
The molar ratios of bis (4-hydroxyphenyl) propane and terephthalic acid were set to 2.0: 8.0: 9.0, and other than that, the polyester resins A to E were used. Similarly, polyester resin F
I got

With respect to the polyester resins A to F, the number average molecular weight Mn, the weight average molecular weight Mw, the glass transition point Tg, the softening point Tm and the acid value were measured as described above, and the weight average molecular weight Mw and the number were measured. Average molecular weight Mn
The ratio (Mw / Mn) was calculated and the result is shown in Table 1 below.
It was shown to.

[0060]

[Table 1]

Next, using the above polyester resins A to F, cyan toners C1 to C6, magenta toners M1 to M6, yellow toners Y1 to Y7, and black toners B1 to B6 are obtained as shown below. It was

(Cyan Toner C1) This Cyan Toner C
In producing 1, the above polyester resin A
And a cyan colorant (manufactured by Toyo Ink Mfg. Co., Ltd .: CI Pigment Blue 15-3) were charged in a pressure kneader at a ratio of 7: 3, these were kneaded, and this kneaded product was pulverized with a feather mill. A pigment masterbatch was obtained.

10 parts by weight of this pigment masterbatch, 93 parts by weight of polyester resin A, and 2 parts by weight of a charge control agent composed of a zinc salicylate complex (E-84 manufactured by Orient Chemical Co.) were used. Was mixed with a Henschel mixer, and this mixture was kneaded with a twin-screw extrusion kneader.

Next, after cooling the kneaded material thus kneaded, the kneaded material is roughly pulverized by a feather mill and further finely pulverized by a jet mill, which is classified to have a volume average particle diameter of 8.0 μm. The obtained toner particles are obtained.

Then, to the toner particles, hydrophobic silica (H1303 manufactured by HDK Co.) was added as an external additive.
4% by weight, hydrophobic titania (manufactured by Titanium Industry Co., Ltd .: STT3)
0A) was added at a ratio of 0.6% by weight, and these were mixed by a Henschel mixer to carry out an addition treatment to obtain a cyan toner C1.

(Cyan Toner C2) This Cyan Toner C
2 is manufactured by replacing the polyester resin A in the cyan toner C1 with the polyester resin B.
Cyan Toner C2 was obtained in the same manner as the above Cyan Toner C1.

(Cyan Toner C3) This cyan toner C
3 is manufactured by replacing the polyester resin A in the cyan toner C1 with the polyester resin C.
Cyan toner C3 was obtained in the same manner as the cyan toner C1 except for the above.

(Cyan Toner C4) This cyan toner C
4 is manufactured by replacing the polyester resin A in the cyan toner C1 with the polyester resin D.
Cyan Toner C4 was obtained in the same manner as the above Cyan Toner C1.

(Cyan Toner C5) This cyan toner C
5 is manufactured by replacing the polyester resin A in the cyan toner C1 with the polyester resin E.
Cyan toner C5 was obtained in the same manner as the cyan toner C1 except for the above.

(Cyan Toner C6) This cyan toner C
6 is manufactured by replacing the polyester resin A in the cyan toner C1 with the polyester resin F.
Cyan Toner C6 was obtained in the same manner as the above Cyan Toner C1.

(Magenta Toner M1) In producing this magenta toner M1, a magenta pigment (CI Pigment Red 184, manufactured by Dainippon Ink and Chemicals, Inc.) is used as a colorant, and otherwise, A magenta toner M1 using the polyester resin A was obtained in the same manner as the cyan toner C1.

(Magenta Toner M2) In manufacturing the magenta toner M2, the polyester resin B is used in place of the polyester resin A in the magenta toner M1, and otherwise the same as the magenta toner M1. To obtain magenta toner M2.

(Magenta Toner M3) In manufacturing the magenta toner M3, the polyester resin C is used instead of the polyester resin A in the magenta toner M1, and otherwise the same as the magenta toner M1. To obtain magenta toner M3.

(Magenta Toner M4) In manufacturing this magenta toner M4, the polyester resin D is used in place of the polyester resin A in the above magenta toner M1, and otherwise the same as in the above magenta toner M1. To obtain magenta toner M4.

(Magenta Toner M5) In manufacturing this magenta toner M5, the polyester resin E is used in place of the polyester resin A in the magenta toner M1, and otherwise the same as the magenta toner M1. To obtain magenta toner M5.

(Magenta Toner M6) When manufacturing this magenta toner M6, the polyester resin F is used instead of the polyester resin A in the above magenta toner M1, and otherwise the same as in the above magenta toner M1. To obtain magenta toner M6.

(Yellow Toner Y1) In manufacturing this yellow toner Y1, a yellow dye (CI Solvent Yellow 16 manufactured by Hoechst Co., Ltd.) is used as a colorant.
2), 2 parts by weight of this yellow dye,
100 parts by weight of the polyester resin A and 2 parts by weight of a charge control agent composed of a zinc salicylate complex (Orient Chemical Co., Ltd .: E-84) were mixed in a Henschel mixer, and the mixture was biaxially extruded. After kneading with a kneader and cooling the kneaded product, this is coarsely pulverized with a feather mill, finely pulverized with a jet mill, and classified to obtain toner particles having a volume average particle diameter of 8.0 μm. It was

Then, to the toner particles, a hydrophobic silica (H1303 made by HDK) as an external additive was added.
4% by weight, hydrophobic titania (manufactured by Titanium Industry Co., Ltd .: STT3)
0A) was added at a ratio of 0.6% by weight, and these were mixed by a Henschel mixer to carry out an addition treatment to obtain a yellow toner Y1.

(Yellow Toner Y2) When manufacturing this yellow toner Y2, the polyester resin B is used in place of the polyester resin A in the above yellow toner Y1, and otherwise the same as the above yellow toner Y1. Yellow toner Y2 was obtained.

(Yellow Toner Y3) In manufacturing the yellow toner Y3, the polyester resin C is used in place of the polyester resin A in the yellow toner Y1, and otherwise the same as the yellow toner Y1. Yellow toner Y3 was obtained.

(Yellow Toner Y4) In manufacturing this yellow toner Y4, a yellow pigment (CI Pigment Yellow 17 manufactured by Toyo Ink Mfg. Co., Ltd.) is used instead of the yellow dye, and otherwise, Yellow toner Y4 using polyester resin C was obtained in the same manner as in the case of cyan toner C3.

(Yellow Toner Y5) In manufacturing this yellow toner Y5, the polyester resin D is used instead of the polyester resin C in the above yellow toner Y4, and otherwise the same as the above yellow toner Y4. Yellow toner Y5 was obtained.

(Yellow Toner Y6) In manufacturing the yellow toner Y6, the polyester resin E is used instead of the polyester resin C in the yellow toner Y4, and otherwise the same as the yellow toner Y4. Yellow toner Y6 was obtained.

(Yellow Toner Y7) In manufacturing the yellow toner Y7, the polyester resin F is used in place of the polyester resin C in the yellow toner Y4, and otherwise the same as the yellow toner Y4. Yellow toner Y7 was obtained.

(Black Toner B1) In the production of this black toner B1, 100 parts by weight of the above polyester resin A was used as a colorant, carbon black (RAVEN1060 manufactured by Columbia Carbon Co., Ltd.).
Was used in the same manner as in the case of the above-mentioned yellow toner Y1 and black toner B1 was obtained.

(Black Toner B2) In producing this black toner B2, the polyester resin B is used in place of the polyester resin A in the above black toner B1, and otherwise the same as the above black toner B1. Black toner B2 was obtained.

(Black Toner B3) In producing this black toner B3, the polyester resin C is used in place of the polyester resin A in the black toner B1, and otherwise the same as in the black toner B1. Black toner B3 was obtained.

(Black Toner B4) In manufacturing this black toner B4, the polyester resin D is used in place of the polyester resin A in the above black toner B1, and otherwise the same as the above black toner B1. Black toner B4 was obtained.

(Black Toner B5) In manufacturing this black toner B5, the polyester resin E is used in place of the polyester resin A in the above black toner B1, and otherwise the same as the above black toner B1. Black toner B5 was obtained.

(Black Toner B6) In manufacturing this black toner B6, the polyester resin F is used in place of the polyester resin A in the above black toner B1, and otherwise the same as in the above black toner B1. Black toner B6 was obtained.

Next, with the above cyan toners C1 to C6,
Magenta toners M1 to M6 and yellow toners Y1 to Y
7 and black toners B1 to B6 as shown in Table 2 below, cyan toner, magenta toner, yellow toner, and black toner are selected to perform full color development of Examples 1 to 3 and Comparative Examples 1 to 4. To obtain toner for use.

[0092]

[Table 2]

A resin-coated carrier manufactured as described below was used as a carrier to be mixed with each of the above toners.

(Production of Carrier) First, 10 ml of methyl ethyl ketone was placed in a 500 ml volumetric flask equipped with a stirrer, a condenser, a thermometer, a nitrogen introducing tube and a dropping device.
While adding 0 part by weight, separately from this, in a nitrogen atmosphere at 80 ° C
In 100 parts by weight of methyl ethyl ketone, 36.7 parts by weight of methyl methacrylate, 5.1 parts by weight of 2-hydroxyethyl methacrylate, 58.2 parts by weight of 3-methacryloxypropyltris (trimethylsiloxy) silane and 1,1 A solution having 1 part by weight of'-azobis (cyclohexane-1-carbonitrile) dissolved therein was prepared, and this solution was added dropwise to the above flask over 2 hours to give 5
Aging was performed for a time to obtain a resin.

Next, for the obtained resin, isophorone diisocyanate / trimethylolpropane adduct (IPDI / TMP system: NCO% = 6.1) was used as a crosslinking agent.
%) Was added so that the OH / NCO molar ratio was 1/1 and then diluted with methyl ethyl ketone to obtain a coating resin solution having a solid ratio of 3% by weight.

Then, the above coating resin solution was applied to the core material made of fired ferrite powder (F-300 manufactured by Powder Tech Co., Ltd.) having an average particle diameter of 50 μm so that the coating resin amount became 1.5% by weight. Then, it was applied with a Spira coater (manufactured by Okada Seiko Co., Ltd.), dried, and the obtained carrier was left standing in a hot air circulation oven at 160 ° C. for 1 hour to be baked, and the baked product was cooled, The ferrite powder bulk was crushed using a sieve shaker equipped with screen meshes with openings of 106 μm and 75 μm to obtain a resin-coated carrier.

Then, the above Examples 1 to 3 and Comparative Examples 1 to 1
The heat-resistant storability of each full-color developing toner of No. 4 was examined, and 94 parts by weight of the resin-coated carrier produced as described above was mixed with 6 parts by weight of each of the above-mentioned toners in each full-color developing toner. Each full-color developing toner mixed with the resin-coated carrier is commercially available full-color copying machine (CF manufactured by Minolta Co., Ltd .: CF
70) and image formation was performed, and the translucency, red reproducibility and green reproducibility of the obtained image were examined, and the results are shown in Table 3 below.

Regarding the heat-resistant storage property, when 5 g of each of the above toners was placed in a glass bottle and left in an environment of 50 ° C. for 24 hours, toner coagulation occurred ×, and slight toner coagulation occurred. When there is no problem in practical use, it is indicated by Δ, and when toner aggregation does not occur, it is indicated by ◯.

Regarding the translucency, a solid image is formed on an OHP film by the above-mentioned full color copying machine,
Visually evaluate the vividness of the color when projected with an overhead projector, and ○ when the color reproducibility is excellent, Δ when practically usable, and × when the saturation is poor.
Displayed in.

Regarding the red reproducibility and the green reproducibility, the developing amounts of the magenta toner and the yellow toner were 0.7 mg / cm by the above-mentioned full-color copying machine.
² for a red image, and the development amount for each of the cyan and yellow toners is 0.7 mg / cm
^A green image is formed on a recording paper so as to be ^2, and the color coordinate of the La ^* b ^* coordinate space is measured for each of the obtained images of each color by a spectrocolorimeter (CM-1000 manufactured by Minolta Co., Ltd.), Each saturation c ^* was calculated based on the following formula. c ^* = (a ^{* 2} + b ^{* 2} ) ^1/2

Regarding the red color reproducibility, the case where the above-mentioned saturation c ^* is 65 or more, which is excellent, is ○, and the saturation c ^* is 6
When the value is 0 or more and less than 65 and can be practically used, the value is Δ, and the saturation c ^*
When the value is less than 60 and there is a problem in practical use, it is indicated by x. Regarding the green reproducibility, when the above-mentioned saturation c ^* is 70 or more and excellent, it is ○, and when the saturation c ^* is 60 or more and less than 70. When practically usable, Δ is shown, and when the saturation c ^* is less than 60 and practically problematic, x is shown.

[0102]

[Table 4]

As is clear from these results, when an image was formed using each of the full-color developing toners of Examples 1 to 3 in which a dye was used as the colorant in the yellow toner, a pigment was added to the colorant in the yellow toner. Compared with the case where images were formed using the full-color developing toners of Comparative Examples 1 to 4 used, the translucency of the obtained images was remarkably improved, and the red reproducibility and the green reproducibility were also improved. And a good full-color image with good color reproducibility was obtained.

[0104]

As described above in detail, in the full-color developing toner according to the present invention, the polyester resin satisfying the above conditions is used as the binder resin in each color toner of cyan toner, magenta toner and yellow toner. Therefore, each color toner exhibits sufficient heat resistant storage stability, fixability, translucency, and color mixing property, and a yellow dye is used in the yellow toner as a colorant in each color toner, and a cyan toner and a magenta toner are used. In the above, since cyan and magenta pigments are used, when a full-color image is formed, the color toners are mixed well so that the color reproducibility is good and the durability is good. And, in particular, a full-color image is formed on the OHP sheet. Case also, without that saturation in the projected image becomes dark or becomes low, so the color reproduction is also good stable full-color image obtained is excellent in transparency.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Arai, 2-3-13 Azuchi-cho, Chuo-ku, Osaka, Osaka International Building Minolta Co., Ltd. (72) Inventor Junichi Tamaki 2-3-3, Azuchi-cho, Chuo-ku, Osaka No. 13 Osaka International Building Minolta Co., Ltd. (72) Inventor Ichiro Izumi 2-3-3 Azuchi-cho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd.

Claims (1)

[Claims] 1. A full-color developing toner used in a full-color image forming apparatus for forming a full-color image by developing at least a predetermined color using at least a cyan toner, a magenta toner, and a yellow toner. The binder resin in each color toner such as toner, magenta toner and yellow toner has an acid value of 1 to
30 mgKOH / g, number average molecular weight Mn is 3000 to 6
000, the ratio (Mw / Mn) of the weight average molecular weight Mw and the number average molecular weight Mn is 2 to 6, and the glass transition point is 50 to 70 ° C.
And a polyester resin having a softening point of 90 to 110 ° C., a cyan pigment as a colorant in the cyan toner, a magenta pigment as a colorant in the magenta toner, and a yellow dye as a colorant in the yellow toner. Toner for full color development.