JPH0731420B2 - Color Toner - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color toner used for visualizing an electric latent image or other electric signals such as an electrophotographic method and an electrostatic recording method, and a color printed image. And form an equivalent image,
The present invention also relates to a color toner excellent in stability over time.

2. Description of the Related Art A color developing method is based on a three-color combining method such as a subtractive coloring method, and as described in US Pat. No. 2,962,374, at least three different electrostatic latent images are formed and then at least different. A method of developing with three color toners and synthesizing on a copy paper is common.

In this case, the performance required for the toner used is more severe than that for obtaining a black image. That is, the toner is required to exhibit and maintain proper color in addition to mechanical and electrical stability against external factors such as impact and humidity.

Examples of using a dye as a colorant include those described in JP-A-57-130043 and 57-130044, and examples of using a pigment include JP-A-
Those described in JP-A-49-46951 and JP-A-52-17023 are also included.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, as the colorant used in the color image toner as described above, those exhibiting a preferable hue and transparency and satisfying good chargeability and durability in continuous use. The current situation is that no has been obtained.

For example, when a dye is used as the colorant, the obtained image has excellent transparency and is clear. However, the image has a problem in durability, and the toner particles using the dye are
When used in an electrophotographic apparatus, carrier particles are used in the two-component developing method, and also in the one-component developing method.
Adhesion of the dye to the charging member makes it difficult to obtain a desired amount of charge, and there is a marked tendency to film each subsystem member or the photoconductor, which causes many problems in terms of stability of image formation over time.

On the other hand, a copy image obtained by a toner using a pigment as a colorant is excellent in light resistance, while the pigment is
Compared to dyes, it is more difficult to disperse in the toner binder resin and it is easier to form pigment aggregates. Such a pigment aggregate not only adversely affects the transparency of the image obtained by electrophotography,
Since the mechanical strength of the pigment agglomerate and the resin interface is weak, the pigment agglomerate is likely to appear on the toner surface during production. Therefore, if pigment aggregates are present in the color toner, then repeatedly,
During use, these pigment aggregates adhere to the carrier particles or the charging member, so that the desired charge amount cannot be obtained.

Further, dyes and pigments generally used as colorants have a great influence on the chargeability of the toner. Therefore, it is more difficult to control the toner chargeability of the color toner than the black toner.

After the toner is fixed on paper, film, etc., in order to achieve good image quality and color reproducibility, the type of coloring material in the toner,
In addition to the concentration and dispersion state, the influence of the binder resin is great.

That is, the toner is the heat, pressure,
Good color reproduction cannot be expected unless the toners of the same color and different colors contact and fix well, because they flow better than black toner due to the energy of the solvent, adhere to the material to be fixed such as paper and film, etc. . At this time, if the toner flows and expands in the lateral direction excessively, the image naturally becomes thick and causes deterioration of image quality such as resolution.

Due to such requirements, a resin having a relatively low molecular weight and / or a low glass transition temperature (Tg) is often used as the binder resin for the color toner. Of course, the transparency of the binder resin is required.

As a matter of course, when a low molecular weight and / or low Tg resin is used as the binder resin, various troubles caused by the bleeding and dropping of the coloring material such as the dyes and pigments described above are further amplified. Become. That is, even if good image quality and color reproducibility are initially obtained, stability over time during repeated use becomes a very serious problem. Also, this problem is
It is further promoted by environmental changes such as humidity.

As described above, a color developer which is satisfactory in both initial image quality and stability has not been obtained so far.

An object of the present invention is to provide a color toner having excellent color reproducibility comparable to that of high quality printing. Therefore,
Improvement of charging, development, transferability, etc., and stability over time,
Another object of the present invention is to provide a color toner having improved environmental stability, dispersibility of coloring material, and improved coloring property.

Means for Solving Problems Estimating the mechanical impact force when iron powder or nickel powder having a diameter of about 100 μm and a specific gravity of about 8 is used as carrier particles in a color developer, the carrier particles are applied to the toner particles. impact force to be generally from 100 kg / cm ^2, it is considered most 200 kg / cm ² or less.

On the other hand, the mechanical strength of toner particles is usually determined by the compression yield value.
It has been experimentally confirmed to be 200 kg / cm ² or more. That is, on average, there is no possibility that the carrier particles will cause the toner to be excessively pulverized, or that the toner particles will stick or stick to the carrier particles. However, in reality, due to stress concentration, hot spots, or the action of magnetic force or electrostatic force, weak portions or defective portions of toner particles are crushed or adhered to the surface of carrier particles, and the developer is considered to deteriorate.

Therefore, in order to improve the stability of the color developer during repeated use, it is sufficient to reduce weak portions and defective portions of the toner particles and prevent deterioration of the developer due to stress concentration and hot spots. In this regard, as a result of the inventors' earnest research, after treating the pigment with the polyester resin, a polyester resin having a lower molecular weight than that used for the treatment is used, and a diluted toner is used. Compared with the case where untreated pigment is used as a service toner,
It was found that the stability of the developer upon repeated use was improved, and that extremely good color reproducibility was obtained.

Therefore, the object of the present invention is achieved by surface-treating a pigment with a polyester resin and then diluting the pigment with a polyester resin having a molecular weight to obtain a toner. (Hereinafter, when the two polyester resins are separately expressed, the former is referred to as “polyester A” and the latter is referred to as “polyester B”.) Further, the toner obtained by the present invention is observed by an electron microscope to disperse the pigment. When the state was observed, it was found that the dispersion unit of the pigment was smaller than that of the conventional toner, and the particles were uniformly dispersed as primary particles of 0.05 to 0.2 μm.

Next, the composition of the color toner of the present invention will be described.

In the color toner of the present invention, as a colorant component,
CI Pigment Red 57: 1, CI Pigment Blue 15: 3
Or, using a pigment belonging to CI Pigment Yellow 12,
In the toner after diluting these pigments with polyester B,
It is preferable to contain 1 to 20% by weight. The above-mentioned pigment used here is extremely excellent in color developability as a single color at the time of image reproduction and color mixing property with color toners of other colors as compared with other organic or inorganic pigments or dyes, and also has light resistance and safety. Since it does not cause any problem in terms of sex, it is advantageously used.

Among the above-mentioned pigments, CI Pigment Red 57: 1 includes Suimei Carmine (Sanmizu dye), Brilliant Carmine 6BD (Sanyo dye), and Priliant Carmine T6B-R.
(Sumika Color), Sumika Print Carmine 6BC (Sumitomo Chemical), Seika First Carmine 6B1476T-7 (Dainichi Seika), No.800 Carmine 6B (Tokyo Color Material), Lionol Red 6B4201 (Toyo Ink), Carmine 6B- Examples include 100 (Japan Pigment), Priliant Carmine 6B (Noma Kagaku), Fuji Carmine 6B (Fuji Dye), and Resino Carmine 6B (Resino Color).

As CI Pigment Blue 15: 3, Lionol Blue FG-7350 (Toyo Ink), Cyanine Blue SSK
(Nippon Pigment), Resino Blue KP-25 (Resino Color), Cyanine Blue KRO (Sanyo Dye), Sumika Print Cyanine Blue GN-O (Sumitomo Chemical), Cyanine Blue
4938 (Dainichi Seika), Fastgen Blue TGR (Dainippon Ink), Heliogen Blue 7080 (BASE), Ingatite Blue GLSM (CIBAGEIGY), Hosta Perm Blue B2G (HO
CHST), Monastral Blue BG (ICI).

Furthermore, CI Pigment Yellow 12 includes Disazo Yellow L3G-G (Sumika Color), Sumika Print Yellow ST-0 (Sumitomo Chemical), No.205N Disazo Yellow, G
R (Daido Chemical), Seika Fast Yellow 2300 (Dainichi Seika), Shimura Fast Yellow GF Conc (Dainippon Ink and Chemicals), Lionol Yellow GR (Toyo Ink), Disazo Yellow GR (Nippon Pigment), Benzidine Yellow
1316 (Noma Chemicals), Resino Yellow GGS (Resino Color), Yellow 152 (Arimoto Chemicals), Suimei Yellow A
(Sanmizu dye) and Pigment Yellow GRT (Sanyo dye).

The pigment concentration in the toner depends on the toner binding resin, the specific gravity of toner constituent materials such as pigments, and the particle size distribution of toner particles,
Furthermore, since it is also affected by the amount of developing toner and the thickness of the toner particle layer, it is difficult to determine in a general way.However, assuming that the layer thickness of the developing toner particles is controlled to about two layers, for example, the average particle size d50 is For toner of about 10 μm, the pigment content is
A preferable range is about 2 to 8% by weight. If the average particle size of the toner is larger, the pigment concentration is naturally lower, and conversely, if the average particle size of the toner is smaller, the pigment concentration is adjusted higher.

When other pigments or dyes are used in combination for the purpose of color tone correction, it is desirable to add them at a concentration of 5% by weight or less in the toner.

The particle size of the toner is d50 = 1 μm
Basically, it is possible to develop coarse toner up to 50> 30 μm, but from the viewpoint of image quality such as resolution and color development, and the suitability of image forming system such as handleability and fixing property of toner particles. , The average particle size d50 of the toner is from about 5 μm to about 20 μm
It is desirable to adopt particles of about m. In addition, the particle size distribution
When expressed in d90 / d10, it is desirable to use a toner having a particle size distribution of d90 / d10 of 5.0 or less, preferably 3.0 or less. The particle size used here is based on the weight average particle size, and the particle size at which the cumulative weight distribution is 50% is represented by the average particle size d50. The particle size distribution is expressed by the ratio d90 / d10 of the particle sizes of 90% and 10% of the cumulative weight distribution. These particle size distributions can be measured by, for example, the Microtrac method.

In the present invention, any known method can be used for treating the pigment with the polyester resin. For example, a melt-kneading method using a two-roll roll, a three-roll roll, a kneader, a Banbury mixer, an extruder, a continuous mixer, or the like, which is usually used in the production of a pigment masterbatch, can be used. Further, the flushing method and the met flushing method, which are often used for the surface treatment of pigments, can also be applied.

For the purpose of helping the dispersion of the pigment in the binder resin, a method of using various solvents, treating with a ball mill, a kneader, a high-speed stirrer or the like and then removing the solvent may be used.

Further, the treatment may be performed by mixing the resin and the pigment in an emulsion state, or by polymerizing and condensing the binder resin in the state where the pigment coexists.

In order to achieve the object of the present invention, at least a part of the surface of the pigment is sufficiently covered with a polyester resin, but for the purpose of strengthening the treatment, a functional group on the pigment surface and a polyester are used. The resin may be chemically bonded by hydrogen bond, ionic bond, or covalent bond.

Incidentally, the ratio of the pigment and the polyester resin when the pigment is treated with the polyester resin has an optimum range depending on the physical properties of the resin used for the treatment, but in consideration of the desired pigment concentration after dilution, the pigment concentration by dilution is considered. Is at least 1 /
It is desirable to determine the ratio so that it becomes 2 or less.

In the present invention, as the polyester resin used for the treatment of the pigment surface and the dilution, all known polyester resins can be used.

For example, as the acid component constituting the polyester resin,
Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid and their derivatives, aliphatic dicarboxylic acids such as adipic acid, pimelic acid, succinic acid, azelaic acid, sebacic acid, decamethylenedicarboxylic acid, fumaric acid And derivatives thereof. As the alcohol component, aliphatic diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol and neopentyl glycol, and The derivative thereof, ethylene oxide or propylene oxide adduct stream of bisphenol A may be mentioned. In the present invention, as the acid component, trimellitic acid, pyromellitic acid, polycarboxylic acids such as benzophenonetetracarboxylic acid are used, or as the alcohol component, glycerin, trimethylolethane, trimethylolpropane, pentaerythriol, etc. It is possible to use a partially cross-linked polyester resin obtained by subjecting a monomer component to condensation polymerization by using the above polyol or both of them at the same time. In the case of unsaturated polyester, a vinyl-based monomer such as styrene or a polymer may be used as the crosslinked polyester resin. Furthermore, a branched polyester obtained by introducing a functional group into the acid component or the alcohol component or both can be used. Among others, aromatic polyesters based on bisphenol derivatives are conveniently used.

Regarding the binder resin, good transparency is
What is strongly demanded is that it is trivial for good color reproduction.

As these polyester resins, those having a glass transition temperature of about 50 ° C. or more are preferably used in order to prevent blocking or filming of the toner. However,
If the glass transition temperature is too high, the fixability and the color developability will be deteriorated. Therefore, particularly in the case of polyester B, it is desirable to control the glass transition point to about 50 to 70 ° C.

On the other hand, if the molecular weight is too low, the toner may be excessively pulverized or filmed at the time of use, causing deterioration of the developer. On the other hand, if the molecular weight is too high, the fixability, color development and color mixing properties deteriorate.

The polyester resin in the present invention has a polystyrene-equivalent molecular weight measured by gel permeation method (GPC), which can sufficiently assure the stability of the developer without impairing the fixability and the color developing property in the following cases. That is, in the case of polyester A, the number average molecular weight is about 2,000 or more, preferably about 3,000 or more, the weight average molecular weight is about 10,000 or more, more preferably about 30,000 or more, and in the case of polyester B, the number average molecular weight is The molecular weight is about 5000 or less, more preferably about 1000 or more to about 3500. The weight average molecular weight of the polyester B is not particularly limited because it varies depending on the developing method, fixing method, etc. of the toner.
It is preferably 10,000 or less, and particularly preferably 40,000 or less because a good color reproduction / fixed image can be obtained at a low temperature.

Both polyesters A and B are not necessarily linear polyesters and may be branched or crosslinked polyesters. In the case of a non-linear polyester, those having a number average molecular weight value by GPC measurement of a solvent-soluble portion such as tetrahydrofuran or chloroform may apparently fall within the above-specified range.

As described above, in the present invention, it is necessary to set the molecular weight of the polyester A larger than that of the polyester B. Only when the molecular weight of the polyester A is set in this way, the charging property of the developer, the stability with time, and the environmental stability can be obtained. The effect of improving the sex becomes remarkable.

In addition, polyester resin is usually -COOH at the end of the molecular chain.
Group and a —OH group. Therefore, it is relatively negatively charged and is used exclusively for negatively charged toner. The polar functional group not only has a great influence on the electrical properties of the toner such as charging property, but also the interaction between the pigment and the binder resin,
It also affects the dispersed state or the fixing property of the toner.
Therefore, it is desirable to set the acid value of polyester A to about 5 or more and the acid value of polyester B to about 5 to 30. When the polyester resin is used as a positively chargeable toner, it is desirable that the acid value be 5 or less by blocking or substituting the —COOH group, but at least when it is used as a negatively chargeable toner, it is appropriate. −COOH or −
The OH group has many advantages in controlling the physical properties of various toners described above. However, if the polar group concentration becomes too high, the humidity dependency becomes strong, or the hydrogen bond becomes too strong, so that a secondary obstacle is likely to occur, and the charging property is rather lowered. Therefore, it is particularly desirable that the polyester B has an acid value of about 5 to 30. Polyester B
When two or more kinds of polyesters are used as the component, even if one type has an acid value of 30 or more, if the acid value of the polyester B component as a whole is about 5 to 30, there is no particular problem.

As the binder resin component, in addition to polyester A and polyester B, if necessary, vinyl-based homopolymers and copolymers such as styrene and acrylic resins, polyamide resins, epoxy resins, phenolic resins, petroleum resins and Hydrogenated petroleum resin, silicone resin, polycarbonate, alkyd resin, urethane resin and urethane compound, fluorine resin, ethylene resin and wax, propylene resin and waxes, paraffin wax, ester wax, etc. are appropriately added for use. May be. However, when using these, it is desirable that the polyester resin accounts for about 70% or more, preferably about 80% or more, of the entire binder resin component.

Also, regarding the ratio of polyester A and polyester B, polyester B is approximately 30% of all binder polyester resins.
% Or more, preferably about 70% or more.

The charge control of the toner may be performed by using the binder resin and the pigment itself, but if necessary, a charge control agent that does not cause a problem in color reproduction may be used together. In the case of the negative charge control agent, metal chelates such as metal-containing dyes and acidic or electron-withdrawing organic substances can be used.

In the case of a positive charge control agent, a quaternary ammonium salt,
In addition, a basic electron-donating organic substance or the like can be used. In that case, it is preferable to treat the terminal carboxyl group of the polyester resin as the binder resin before use.

These charge control agents may be mixed and added to the toner binder resin, or may be used in the form of being attached to the surface of the toner particles. Further, for the purpose of removing the influence of the pigment on the toner chargeability, these charge control agents may be added during the treatment of the pigment.

Further, in addition to the above charge control agent, a solid electrolyte, a polymer electrolyte, a charge transfer complex, a metal oxide such as tin oxide, silica, alumina, titanium oxide, or the like, or a ferroelectric substance, a magnetic substance, or the like is added to the toner. It is also possible to control the electrical properties.

In addition, extenders, reinforcing fillers such as fibrous substances, thermal properties, mechanical property modifiers, preservatives, antioxidants, deodorants, foaming agents, release agents, adhesives, Etc. can be added as needed.

Further, it improves the powder fluidity or chargeability of the toner on the surface of the toner particles, prevents the filming of the toner on the surface of the photoconductor or carrier particles, or further cleans the residual toner on the photoconductor. Various external additives can be attached or fixed for the purpose of improving

These external additives include long-chain fatty acids such as stearic acid and their esters, amides, metal salts, and further tin oxide, fluorinated graphite, silicon carbide, boron nitride, silica, aluminum oxide, titanium dioxide, zinc oxide and the like. It is possible to use fine powders, fine powders such as fluororesins and acrylic resins, polycyclic aromatic compounds, wax-like substances, crosslinked or non-crosslinked resin fine powders, and the like. Solid surface fine particles having a low surface energy of 30 dyn / cm or less of the critical surface tension or having a smooth surface with a friction coefficient of 0.1 or less, or non-adhesive particles having a slight abrading property are used for improving fluidity and preventing filming. In order to be especially desirable.

As a method for visualizing an electric latent image and other electric signals by using the color toner of the present invention, all known developing methods can be applied, such as ordinary two-component developing method and microtoning method. In addition to the above, a one-component developing method using no carrier can be applied.

Although the detailed mechanism of the action of the present invention is not always clear,
Considering from the results of observation with an electron microscope, by treating the pigment surface with the resin, the wetting of the pigment and the binder resin was improved, so that the pigment was uniformly dispersed and the mechanical interface of the pigment and resin It is considered that this is because the strength was increased and it became difficult for the pigment to come off from the binder resin. In addition, since the pigment surface is coated with a resin having a higher molecular weight than the resin used for dilution, the portion of the resin with a low molecular weight used for dilution in the toner becomes the pulverization interface during pulverization during the toner manufacturing process. In addition, it is considered that the pigment is less likely to be exposed on the toner surface.

Examples Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples as a matter of course. In the examples, “parts” means “parts by weight” unless otherwise specified.

Example 1 Polyester 75 parts (Tg = 63 ° C., number average molecular weight = 3,800, weight average molecular weight = 85,000, acid value = 25) Pigment (Rionol Red 6B4201) 25 parts A mixture having the above composition was mixed with a kneader to give 150 The mixture was heated at 0 ° C., melted, and then mixed while being cooled. Then, it passed through two rolls and was molded into pellets.

Then, the following composition, namely, 80 parts of polyester (Tg = 55 ° C., number average molecular weight = 2,400, weight average molecular weight = 7,200, acid value = 18) A mixture of 20 parts of the above pellets was well mixed with a kneader. After that, it was roughly pulverized with a cutter mill and further pulverized with a fine pulverizer using a jet stream.

The obtained pulverized product was classified using an air classifier, and the average particle size d5
A fine powder of 0 = 12 μm was obtained. Further, 0.8% by weight of silica fine powder (Aerosil R-972) was mixed with the fine powder to obtain a magenta toner.

3 parts of the above toner was mixed with 100 parts of a carrier prepared by coating ferrite with a memomethacrylate / styrene / 2-vinylpyridine terpolymer and a silicone / methylmethacrylate graft copolymer to obtain a developer.

When the blow-off charge amount of the toner in this developer was measured,
It was -20 μc / g. In addition, the charge distribution is narrow and high.
Change in charge distribution under conditions of high temperature and low temperature to low temperature and low humidity
It was small. FX-2300 with this developer Copier remodeling machine
When an image is formed with, it is excellent in transparency and color development.
A clear image of magenta color was obtained. 10000 more continuous
Even in copying, there was almost no change in image quality.

Example 2 Polyester 75 parts (Tg = 68 ° C., partially crosslinked polyester, number average molecular weight of solvent-soluble component = 5,400, weight average molecular weight = 85,000, acid value = 12) Pigment (Sumika Print Carmine 6BC) 25 parts Melt flushing treatment was performed to obtain pellets. Using this pellet, a toner was prepared by diluting it with polyester in the same manner as in Example 1, and a test was conducted. As a result, the blow-off charge amount of the toner in the developer was -18 μc / g, the charge distribution was narrow, and the toner had good quality. A clear magenta image was obtained. Moreover, even after continuous copying of 10,000 sheets, there was almost no change in image quality. Further, similar results were obtained even under high temperature and high humidity.

Example 3 Polyester 90 parts Pigment (Lionol Red 6B-4201) 10 parts Also, the same operation as in Example 1 was carried out except that the dilution ratio was 75 parts polyester and 25 parts pellets. The amount of blow-off charge of the toner in the agent was −17 μc / g, and a clear image of good quality was obtained as in Example 1. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 4 The magenta toner of Example 2 was treated with perfluorosilane.
1.0 parts by weight of fine powder was added to obtain a toner. This Tona
Using a modified silicone resin as the charging blade.
FX-2300 equipped with a component developing machine Image type with copier remodeling machine
As a result, the magenta of the same quality as in Example 2 was obtained.
A color image was obtained. Also, even with continuous copying of 10,000 sheets,
Almost no change in image quality was seen. Furthermore, high temperature and high humidity
Similar results were obtained below.

Example 5 In Example 2, the polyester used for dilution was replaced with polyester (Tg = 67 ° C., number average molecular weight = 2,300, weight average molecular weight = 6,600, acid value = 17) to prepare a magenta toner, and the test was conducted. As a result, the amount of blow-off charge of the toner in the developer was -19 μc / g, and a high-quality clear image was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 6 In Example 3, a magenta toner was manufactured by changing the polyester used for dilution to a mixed polyester composed of 30 parts of polyester and 70 parts of polyester, and a test was conducted. As a result, the blow-off charge amount of the toner in the developer was , −21 μc / g, and a clear image of good quality was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 7 In Example 1, the polyester used for dilution was replaced with polyester (Tg = 62 ° C., number average molecular weight = 4,200, weight average molecular weight = 27,000, acid value = 13), and the treated pigment was used as in Example 1. Similarly, a toner was prepared by diluting with polyester. When this toner was tested in the same manner as in Example 1, the blow-off charge amount of the toner in the developer was −19 μc / g, and the same clear image was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Comparative Examples 1A to 1E Comparative Example 1A Polyester 95 parts Pigment (Rionol Red 6B4201) 5 parts Comparative Example 1B Polyester 95 parts Pigment (Rionol Red 6B4201) 5 parts Comparative Example 1C Polyester 95 parts Pigment (Rionol Red 6B4201) 5 parts Comparative Example 1D Polyester 95 parts Pigment (Rionol Red 6B4201) 5 parts Comparative Example 1E Polyester 95 parts Pigment (Rionol Red 6B4201) 5 parts The mixture having the above composition was simultaneously mixed with a kneader to obtain a magenta toner.

Comparative Example 2 15 parts polyester 80 parts polyester 80 parts Pigment (Lionol Red 6B4201) 5 parts The mixture having the above composition was simultaneously mixed with a kneader to obtain a magenta toner.

Comparative Example 3 A toner was obtained in the same manner as in Example 1 except that polyester was used instead of polyester and polyester was used instead of polyester.

Table 1 shows the results of tests performed on the toner of Example 1 and the toners of Comparative Examples 1 to 3 above.

Example 8 Polyester 75 parts Pigment (Cyanine Blue 4938) 25 parts A mixture having the above composition was heated at 150 ° C. by a kneader to melt it, and then mixed while being cooled. Then, the mixture was passed through two rolls and molded into pellets.

Then, the following composition, that is, 80 parts of polyester, a mixture consisting of 20 parts of the above pellets was mixed well with a kneader, coarsely pulverized with a cutter mill, and further pulverized with a fine pulverizer using a jet stream. did.

The obtained pulverized product was classified using an air classifier, and the average particle size d5
A fine powder of 0 = 12 μm was obtained. Further, 0.8% by weight of fine silica powder (Aerosil R-972) was mixed with the fine powder to obtain a cyan toner.

3 parts of the above toner was mixed with 100 parts of the same carrier as in Example 1 to obtain a developer.

When the blow-off charge amount of the toner in this developer was measured,
Around -17 μc / g. In addition, the charge distribution is narrow and high.
Change in charge distribution under conditions of high temperature and low temperature to low temperature and low humidity
It was small. FX-2300 with this developer Copier remodeling machine
When an image is formed with, it is excellent in transparency and color development.
A clear cyan image was obtained. Furthermore, 10000 consecutive sheets
Even in copying, there was almost no change in image quality.

Example 9 Polyester 75 parts Pigment (Sumika Print Cyanine Blue GN-0) 25 parts The above composition was melt-flushed to give pellets. Using this pellet, a cyan toner was obtained by diluting it with polyester in the same manner as in Example 8, and a test was conducted. As a result, the blow-off charge amount of the toner in the developer was −16 μc /
g, the charge distribution was narrow, and a clear cyan image of good quality was obtained. Moreover, even after continuous copying of 10,000 sheets, there was almost no change in image quality. Further, similar results were obtained even under high temperature and high humidity.

Example 10 Polyester 90 parts Pigment (cyanine blue 4938) 10 parts Also, the same operation as in Example 1 was carried out except that the dilution ratio was 75 parts polyester and 25 parts pellets. The toner blow-off charge amount was −19 μc / g, and a high-quality clear image was obtained as in Example 1. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 11 The toner of Example 9 was added with perfluorosilane-treated silica fine powder.
Powder (1.0 part by weight) was added to obtain a toner. Use this toner
A single component that uses a modified silicone resin as a charging blade.
I attached an image machine. FX-2300 Image formation with a copier remodeling machine
Incidentally, a cyan image of good quality as in Example 9
The image was obtained. In addition, even with continuous copying of 10,000 sheets, the image quality
Little change was seen. Furthermore, under high temperature and high humidity
Also obtained similar results.

Example 12 In Example 9, the polyester used for dilution was replaced with polyester to produce a cyan toner, and a test was conducted. The blow-off charge amount of the toner in the developer was -18 μc / g, which was of good quality. A clear image was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 13 In Example 3, a cyan toner was manufactured by replacing the polyester used for dilution with a mixed polyester composed of 30 parts of polyester and 70 parts of polyester, and a test was carried out. As a result, the blow-off charge amount of the toner in the developer was ,
It was −17 μc / g, and a clear image of good quality was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 14 In Example 8, the polyester used for dilution was replaced with polyester, and the treated pigment was diluted with polyester in the same manner as in Example 8 to produce a toner. When this toner was tested in the same manner as in Example 1, the toner blow-off charge amount in the developer was
It was −17 μc / g, and a similar clear image was obtained. Also, 1
No change in image quality was observed even after continuous copying of 0000 sheets.
Further, similar results were obtained even under high temperature and high humidity.

Comparative Examples 4A to 4E Comparative Example 4A Polyester 95 parts Pigment (Cyanine Blue 4938) 5 parts Comparative Example 4B Polyester 95 parts Pigment (Cyanine Blue 4938) 5 parts Comparative Example 4C Polyester 95 parts Pigment (Cyanine Blue 4938) 5 parts Comparative Example 4D Polyester 95 parts Pigment (Cyanine Blue 4938) 5 parts Comparative Example 4E Polyester 95 parts Pigment (Cyanine Blue 4938) 5 parts The mixture having the above composition was simultaneously mixed with a kneader to obtain a cyan toner.

Comparative Example 5 Polyester 15 parts Polyester 80 parts Pigment (Cyanine Blue 4938) 5 parts The mixture having the above composition was simultaneously mixed with a kneader to obtain a cyan toner.

Comparative Example 6 A toner was obtained in the same manner as in Example 8 except that polyester was used instead of polyester and polyester was used instead of polyester.

Table 2 shows the test results of the toner of Example 8 and the toners of Comparative Examples 4 to 6.

Example 15 Polyester 75 parts Pigment (Disazo Yellow L3G-G) 25 parts A mixture having the above composition was heated at 150 ° C. by a kneader to melt it, and then mixed while being cooled. Then, it passed through two rolls and was molded into pellets.

Then, the following composition, that is, 80 parts of polyester, a mixture consisting of 20 parts of the above pellets was mixed well with a kneader, coarsely pulverized with a cutter mill, and further pulverized with a fine pulverizer using a jet stream. did. The obtained pulverized product was classified using an air classifier to obtain a fine powder having an average particle diameter d50 = 12 μm. Furthermore, silica fine powder (Aerosil R-972) is added to the fine powder.
0.8% by weight was mixed to obtain a yellow toner.

3 parts of the above toner was mixed with 100 parts of the same carrier as in Example 1 to obtain a developer.

When the blow-off charge amount of the toner in this developer was measured,
It was -20 μc / g. In addition, the charge distribution is narrow and high.
Change in charge distribution under conditions of high temperature and low temperature to low temperature and low humidity
It was small. FX-2300 with this developer Copier remodeling machine
When an image is formed with, it is excellent in transparency and color development.
A clear yellow image was obtained. 10000 more continuous
Even in copying, there was almost no change in image quality.

Example 16 Polyester 75 parts Pigment (Sumika Print Yellow ST-0) 25 parts The above composition was melt-flushed to give pellets. Using this pellet, a yellow toner was obtained by diluting with polyester in the same manner as in Example 15, and a test was carried out.The blow-off charge amount of the toner in the developer was -20 μc /
g, the charge distribution was narrow, and a clear yellow image of good quality was obtained. Moreover, even after continuous copying of 10,000 sheets, there was almost no change in image quality. Further, similar results were obtained even under high temperature and high humidity.

Example 17 Polyester 90 parts Pigment (Disazo Yellow L3G-G) 10 parts Also, the same operation as in Example 15 was carried out except that the dilution ratio was 75 parts polyester and 25 parts pellets. The blow-off charge amount of the toner inside was −23 μc / g, and a clear image of good quality was obtained as in Example 15. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 18 The toner of Example 16 was mixed with perfluorosilane-treated silica fine powder.
The powder was added in an amount of 1.0 part by weight to obtain a toner. Use this toner
A single component that uses a modified silicone resin as a charging blade.
I attached an image machine. FX-2300 Image formation with a copier remodeling machine
A good yellow color as in Example 16
An image was obtained. In addition, even with continuous copying of 10,000 sheets, the image quality
Almost no change was observed. Furthermore, under high temperature and high humidity
Also obtained similar results.

Example 12 In Example 16, the polyester used for dilution was replaced with polyester to produce a yellow toner, and a test was conducted.The toner blow-off charge amount in the developer was -18 μc / g, which was a good quality. A clear image was obtained.
In addition, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 19 In Example 16, the polyester used for dilution was replaced with polyester to produce a toner, and a test was conducted.The blow-off charge amount of the toner in the developer was −22.
It was μc / g, and a clear image of good quality was obtained. Also, 10000
No change in image quality was observed even after continuous copying. Further, similar results were obtained even under high temperature and high humidity.

Example 20 In Example 17, the polyester used for dilution was replaced with a mixed polyester consisting of 30 parts of polyester and 70 parts of polyester to produce a yellow toner, which was tested, and the blow-off charge amount of the toner in the developer was , −21 μc / g, and a clear image of good quality was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Example 21 In Example 15, the polyester used for dilution was replaced with polyester (Tg = 62 ° C., number average molecular weight = 4,200, weight average molecular weight = 27,000, acid value = 13), and the treated pigment was used as in Example 1. Similarly, a toner was prepared by diluting with polyester. When this toner was tested in the same manner as in Example 1, the toner blow-off charge amount in the developer was −21 μc / g, and the same clear image was obtained. Moreover, no change in image quality was observed even after continuous copying of 10,000 sheets. Further, similar results were obtained even under high temperature and high humidity.

Comparative Examples 7A to 7E Comparative Example 7A Polyester 95 parts Pigment (Disazo Yellow L3G-G) 5 parts Comparative Example 7B Polyester 95 parts Pigment (Disazo Yellow L3G-G) 5 parts Comparative Example 7C Polyester 95 parts Pigment (Disazo Yellow L3G-G) ) 5 parts Comparative Example 7D Polyester 95 parts Pigment (Disazo Yellow L3G-G) 5 parts Comparative Example 7E Polyester 95 parts Pigment (Disazo Yellow L3G-G) 5 parts The mixture of the above composition is mixed at the same time with a kneader to give a yellow color. Toner was obtained.

Comparative Example 8 Polyester 15 parts Polyester 80 parts Pigment (Disazo Yellow L3G-G) 5 parts The mixture having the above composition was simultaneously mixed with a kneader to obtain a yellow toner.

Comparative Example 9 A toner was obtained in the same manner as in Example 15, except that polyester was used instead of polyester and polyester was used instead of polyester.

Table 3 shows the test results of the toner of Example 15 and the toners of Comparative Examples 7 to 9 described above.

As described above, the color toner of the present invention comprises the pigment coated with the polyester resin having a higher molecular weight and then dispersed in the polyester resin having a lower molecular weight. It does not easily migrate into the resin and the dispersibility of the pigment is good. In addition, the probability that impurities mixed in in the pigment manufacturing process, or rosins added to control the pigment characteristics, treatment agents such as surfactants, etc. will migrate to the low molecular weight polyester resin of the toner will decrease. Therefore, the charging property of the toner is less affected.

Further, since the pigment is coated with the high molecular weight polyester resin, there is an advantage that the mechanical strength of the toner is improved and the toner is prevented from being deteriorated even though the color toner is low melt and has high color forming property.

Furthermore, since the pigment is less likely to be exposed on the surface of the toner particles, the effect of the charging property of the pigment on the charging property of the toner is reduced, and the charge distribution of the toner becomes sharp. Moreover, since the pigment is less likely to fall out of the toner, the repeated development operation for a long period of time becomes possible.

Further, as a pigment, CI Pigment Red 57: 1, CI Pigment Blue 15: 3, or CI Pigment Yellow 12
When a pigment belonging to the category (1) is used, the color development as a single color at the time of image reproduction and the color mixing property with other color toners are excellent, and the weather resistance and safety are satisfactory.

When these pigments are used in a negatively chargeable toner or a positively chargeable toner, there is a problem that it is difficult to control the charge of the toner. However, the present invention also has an effect of improving such a defect. .

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Kenji Ogi 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Xerox Co., Ltd. Takematsu Plant (72) Hidehiko Soyama 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Xerox Co., Ltd. Takematsu Business In-house (56) Reference JP 61-65258 (JP, A) JP 61-80262 (JP, A) JP 57-116348 (JP, A)

Claims (5)

[Claims] 1. A color toner comprising a polyester resin and a pigment coated with the polyester resin having a higher molecular weight than the polyester resin dispersed therein. 2. The color toner according to claim 1, wherein the pigment is a process pigment. 3. CI Pigment Yellow as a pigment
The yellow toner according to claim 1, wherein 12 is used. 4. CI Pigment Blue 1 as a pigment
The cyan toner according to claim 1, which uses 5: 3. 5. CI Pigment Red 5 as a pigment
The magenta toner according to claim 1, which uses 7: 1.