JPH0640227B2 - Positively chargeable toner composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positively chargeable toner composition used in electrophotography.

Conventionally, developing methods in electrophotography, electrostatic recording and the like are roughly classified into a dry developing method and a wet developing method. The former is further divided into a method of using a two-component developer and a method of using a one-component developer.

Among the two-component developing methods, there are a magnet brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using a fur, etc., depending on the type of carrier that carries the toner.

The one-component developing method includes a powder cloud method in which toner particles are sprayed, and a contact developing method (contact developing or toner developing in which toner particles are brought into direct contact with an electrostatic latent image surface for development). (Also referred to as), a jumping developing method in which toner particles are not directly contacted with the electrostatic latent image surface, but the toner particles are charged and fly toward the latent image surface by an electric field of the electrostatic latent image, magnetic conductive toner. There is a magnetic dry method for developing by contacting with the electrostatic latent image surface.

In the two-component developing method, a mixed developer of carrier particles and toner particles is inevitably used, and the toner particles are usually consumed in a much larger amount than the carrier particles due to the progress of the developing process, or the mixture ratio of both is increased. And the density of the visible image fluctuates, and the image quality is deteriorated due to deterioration of carrier particles which are difficult to be consumed due to long-term use.

On the other hand, in the one-component developing method, in the magnetic dry method using magnetic toner and the contact developing method not using magnetic toner, the toner indiscriminately contacts the entire surface to be developed, that is, the image area and the non-image area, For this reason, the toner is likely to adhere even to the non-image area, so that there is a problem that so-called background fog is apt to occur and stains occur. (This fog stain point is also a drawback that occurs in the two-component developing method as well. ). or,
Also in the powder cloud method, it is inevitable that toner particles in a powder state adhere to the non-image portion, and similarly, there is a drawback that the background fog cannot be removed.

In this respect, JP-A-54-43027 and JP-A-55-
No. 18656, etc., an electrostatic image carrier that holds an electrostatic image on the surface and a toner carrier that holds an insulating toner on the surface are arranged in the developing unit with a certain gap, Is carried on the toner carrier to a thickness smaller than the gap, and the toner is transferred to the electrostatic image carrier in the developing section to develop the toner. It has the advantage that it is hard to come out.
Further, since no carrier particles are used, it can be said that this is an electrostatic image developing method with high fidelity and stable image quality without the above-mentioned situation of fluctuation of the mixing ratio and further without deterioration of carrier particles. However, as a problem of this method, it is necessary that the toner layer on the toner carrier is uniform. If not, uneven density of the image and background fog occur, and only an unsightly image is obtained. Therefore, in order to improve the transportability of the toner on the toner carrier, a magnet is arranged in the toner carrier to use a toner containing a magnetic material. According to this method, a uniform thin layer is formed. The coat can be obtained relatively stably, but since the toner contains a magnetic substance, the fixing property is deteriorated, the easiness of damaging the photoconductor is increased,
There is a possibility that problems such as deterioration of the hue of the chromatic toner may occur.

Therefore, an electrostatic image carrier that holds the electrostatic image on the surface and a toner carrier that carries the toner on the surface are arranged with a certain gap in the developing section, and the saturation magnetization at an external magnetic field of 5000 Oe is 10emu / A developing method is conceivable in which a toner of g or less is carried on a toner carrier to a thickness smaller than the gap, and the toner is transferred to the electrostatic holder at a developing section. With this method, it is of course possible to take advantage of the one-component jumping development for development.
The toner can be finely coated on the toner carrier regardless of the presence or absence of the magnetic substance in the toner. However, the toner may not always be uniformly charged due to a change in the total amount of the developer or the like, and the toner coat state is likely to be defective due to the case.

As the positive charge control agent used in such a dry developing toner, for example, there are generally quaternary ammonium compounds and organic dyes, especially basic dyes and salts thereof.
Usual positive charge controlling agents are benzylmethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, nigrosine base, nigrosine, safranine γ and crystal violet. In particular, nigrosine base and nigrosine are often used as positive charge control agents. These are usually added to a thermoplastic resin, thermally melt-dispersed, finely pulverized, and prepared to have an appropriate particle size as needed, and used.

However, these dyes as charge control agents have a complicated structure and inconsistent properties, and thus have poor stability. In addition, decomposition or deterioration is likely to occur due to decomposition during mechanical kneading, mechanical shock, friction, changes in temperature and humidity conditions, etc., and a phenomenon in which charge controllability is deteriorated is likely to occur.

Therefore, when a toner containing these dyes as a charge control agent is developed using a copying machine, the charge control agent may be decomposed or deteriorated as the number of times of copying increases, and the toner may deteriorate during its durability.

In addition, most of the substances generally known to be positively charged have a dark color and thus cannot be contained in a vivid chromatic color developer.

Further, since it is extremely difficult to uniformly disperse these positive charge control agents in the thermoplastic resin, there is a fatal defect that the triboelectric charge amount is different between the toner particles obtained by pulverization. is doing. For this reason, various methods have been conventionally used for more uniform dispersion. For example, a basic nigrosine dye is used in the form of a salt with a higher fatty acid in order to improve the compatibility with a thermoplastic resin, but the unreacted fatty acid or a dispersion product of the salt is often used.
It is exposed on the surface of the toner and contaminates the carrier or the toner carrier, which causes deterioration of toner fluidity, fog, and reduction of image density. Alternatively, in order to improve the dispersion of these charge control agents in the resin, a method of mechanically pulverizing and mixing the charge control agent powder and the resin powder in advance and then hot-melt kneading is used. But,
The original dispersion failure can be avoided. At present, it is not possible to obtain sufficient charge uniformity for practical use.

In addition, many of the positive charge control agents are hydrophilic, and due to poor dispersion in these resins, when they are pulverized after melt kneading,
The dye is exposed on the toner surface. Therefore, when the toner is used under high humidity conditions, these charge control agents are hydrophilic, so that a high quality image cannot be obtained.

As described above, when the conventional positive charge control agent is used for the toner, the toner particle surface is formed between the toner particles, or between the toner and the carrier, and between the toner carrier such as the toner and the sleeve. The amount of generated charges varies, and troubles such as development fog, toner scattering, and carrier contamination are likely to occur. In addition, this obstacle appears as a remarkable phenomenon when a large number of copies are piled up, and is substantially unsuitable for a copying machine.

Further, under high humidity conditions, the transfer efficiency of toner images is significantly reduced, and many of them cannot be used. Even when the toner is stored for a long period of time even at room temperature and normal humidity, it often becomes unusable due to instability due to instability of the positive charge control agent used.

An object of the present invention is to provide a positively chargeable toner which has improved the above-mentioned drawbacks.

That is, an object of the present invention is to provide a positively chargeable toner that has little dependence on the ratio of the toner to the carrier, the change in the total amount of the developer, and the like.

That is, an object of the present invention is to provide a positively chargeable toner having excellent durability such as continuous use characteristics.

Another object of the present invention is to provide a positively chargeable toner that is stable against environmental changes such as high temperature and high humidity and low temperature and low humidity.

That is, the present invention relates to a positively chargeable toner composition characterized in that a binder resin contains a pigment obtained by lakeizing a dye represented by the following general formula. [Wherein R ₁ , R ₂ , R ₄ and R ₅ are independently hydrogen,
And a lower alkyl group which may be substituted with a hydroxyl group or an alkoxy group, wherein R ₃ and R ₆ are each independently hydrogen, a phenyl group, a hydroxyl group, or a lower alkyl group which may be substituted with an alkoxy group; Group, R ₇ represents a phenyl group, and A ⁻ represents an anion. ] Examples of the dye used in the present invention include the following.

(1) (2) (3) The lake formation of the dye is carried out by a known method.

For example, an aqueous solution of a lake agent is added to an aqueous solution of dye in acetic acid to precipitate a lake pigment. Alternatively, the extender pigment is suspended in an aqueous acetic acid solution of a dye, and then an aqueous solution of a laker is added to deposit the lake pigment on the surface of the extender pigment. The lake pigment is filtered, washed with water and dried. Examples of the raking agent include phosphotungstic molybdic acid, phosphotungstic acid, water-soluble salts of phosphomolybdic acid and water-soluble salts containing complex anions such as ferrocyan and ferricyan. An organic acid salt may be used as a laker, but gallic acid lakes, for example, do not have very good charging characteristics. It is considered that this is because the organic acid lake has a good compatibility between the resin and the lake, so that the property of the resin having a poor charging property is remarkably exhibited.

As a developing method using the toner composition of the present invention,
An electrostatic image carrier that holds an electrostatic image on the surface and a toner carrier that carries toner on the surface are arranged in the developing unit with a constant gap, and the saturation magnetization is 10 emu / g or less in an external magnetic field of 5000 Oe. It is preferable that the toner of (1) is carried on a toner carrier to a thickness smaller than the gap, and the toner is transferred to the electrostatic holder at a developing section.

As a result of various studies on conventionally known non-magnetic or weakly magnetic toners using the above-described developing method, the present inventors have found that in order to solve the above-mentioned drawbacks, the developing method using magnetic toner is more effective than the developing method using magnetic toner. It was found that more precise control of the amount of electrostatic charge of the toner on the toner carrier is important in some parts. That is, in the developing method using the insulating non-magnetic toner, for example, when the charge amount is low, the toner is not uniformly applied on the toner carrier, which cannot be developed. If the value is not appropriate even when the applied state is made, the background fog is likely to occur. On the contrary, if the value is too high, the electrostatic attraction with the toner carrier is too strong and the toner holds the electrostatic image. It becomes difficult to transfer to the body, resulting in a decrease in image density and appearance of low-quality images. Further, for the same reason, the image quality is greatly affected by repeated use or a change in toner charge amount due to environmental changes. Therefore, it is extremely important to ensure the stability of the charge amount. Further, the physical adhesive force between the toner and the toner carrier obviously affects the transfer of the toner from the toner carrier, and for example, the degree of freedom of each toner is small and the toner coating density in the toner layer on the toner carrier is small. If it is large, the image density will be low and a low-quality image with low resolution will be obtained. Therefore, it is also very important to prevent the physical adhesive force from increasing.

As a result of earnest research, the present inventor has found that, when the lake pigment is contained in the toner as described above, an electrophotographic toner exhibiting excellent characteristics can be obtained. Further, they have found that it is very effective to apply this developer to the above developing method.

That is, the toner containing the lake pigment has a high triboelectric chargeability and a good durability against repeated continuous photography, and when it is applied to the above-mentioned developing method, it is stable even in an environment of high temperature and high humidity and low temperature and low humidity. It has become possible to extract high-quality images over a long period of time.

As a method of incorporating the lake pigment in the present invention into the toner, there are a method of adding it inside the developer and a method of adding it externally. When internally added, the control agent content is 100 wt.
%, Preferably 0.1 to 50 wt%, and more preferably 0.5 to 20 wt%. Further, when externally added, 0.01 to 40 wt% is preferable, and particularly 0.05 to 10 wt% is more preferable with respect to 100 wt% of the resin.

As the binder resin for the toner used in the developing method of the present invention, various material resins conventionally known as electrophotographic toner binder resins are used.

For example, polystyrene, polystyrene-butadiene copolymer, styrene-acrylic copolymer, and other styrene-based copolymers, polyethylene, polyethylene-vinyl acetate copolymer,
Examples thereof include ethylene-based copolymers such as polyethylene vinyl alcohol copolymer, phenol-based resins, epoxy-based resins, allyl phthalate resins, polyamide resins, polyester resins and maleic acid-based resins. In addition, the manufacturing method and the like of each resin is not particularly limited. This is because the resin conventionally produced by emulsion polymerization or the like contains impurities easily and is difficult to use. However, according to the present invention, the resin can be easily used, and the range of resin selection is greatly expanded. This is also a great effect of the present invention.

As the coloring material used in the toner of the present invention, conventionally known coloring materials such as carbon black, dyes and pigments can be used.

If necessary, a fluidity improver such as silica or alumina may be added to the toner.

When it is desired to obtain a magnetic toner, magnetic fine particles may be added to the toner. The magnetic substance exhibits magnetism, but any magnetizable material may be used, and examples thereof include metals such as iron, manganese, nickel, cobalt, and chromium, magnetite, various ferrites, manganese alloys, and other ferromagnetic alloys. What was made into the fine powder can be used.

Hereinafter, the usage of the toner of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of an embodiment of an electrostatic latent image developing method and a developing device using an insulating toner. In the figure, reference numeral 1 denotes a cylindrical electrostatic image carrier, and an electrostatic latent image is formed on the electrostatic image carrier by, for example, the well-known electrophotographic method such as the Carlson method or the NP method. The insulating toner 5 is developed with the toner 5 applied by the applying means 4 for applying the insulating toner 5 on the toner carrier 2 while controlling the layer thickness of the toner layer.
The toner carrier 2 is a cylindrical developing roller made of stainless steel. Aluminum may be used as the material of the developing roller, or other metal may be used. It is also possible to use a metal roller coated with a resin or the like on the metal roller in order to frictionally charge the toner to a more desired polarity. Further, the developing roller may be made of a conductive non-metallic material. Although not shown, both ends of this toner carrier 2 are provided with spacer rollers made of high-density polyethylene on their shafts. By applying the spacer rollers to both ends of the electrostatic image carrier 1 to fix the developing device, the electrostatic image carrier 1
The distance between the toner carrier 2 and the toner carrier 2 is set to be equal to or larger than the thickness of the toner layer applied on the toner carrier 2 and held. This interval is, for example, 100 μ to 500 μ, preferably 150 μ to 30
0 μ. If this interval is too large, the electrostatic force exerted by the electrostatic latent image on the electrostatic image carrier 1 on the non-magnetic toner applied on the toner carrier 2 becomes weak and the image quality deteriorates, especially due to the development of glue lines. Visualization becomes difficult. If this interval is too narrow, there is a great risk that the toner coated on the toner carrier 2 will be compressed and aggregated between the toner carrier 2 and the electrostatic image carrier 1. A developing bias power source 6 is adapted to apply a voltage between the conductive toner carrier 2 and the back electrode of the electrostatic image carrier 1. This developing bias voltage is the developing bias voltage as described in Japanese Patent Application No. 53-92108.

FIG. 2 is another example of the embodiment. In the figure, 1
Is an electrostatic image carrier, 2 is a toner carrier, 5 is the toner specified in the present invention, 3 is a hopper, 9 is a cleaning blade,
Reference numeral 10 denotes a toner supply member. 16 is a vibrating member, 17 is a vibration generating means, 16a is a permanent magnet, 16b is a support spring,
17a is a core and 17b is a winding. An alternating current is applied to the winding 17b to vibrate the vibrating member 16 at an appropriate amplitude frequency,
A uniform toner coating layer is formed on the toner carrier 2 which is rotating at a constant speed, and the toner carrier 2 and the electrostatic image carrier 1 are opposed to each other with a gap larger than the thickness of the toner coating layer being maintained. It flies to an electrostatic image and develops. The vibration of the vibrating member 16 may be any as long as it does not come into direct contact with the toner carrier 2, but the thickness of the toner coating layer is 5 to 1
It is preferable to control the frequency and amplitude so as to be uniform at about 00μ. It is also possible to apply an AC or / and DC developing bias voltage between the toner carrier 2 and the electrostatic image carrier 1.

FIG. 3 is another example of the embodiment. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, 3 is a developing container, 5 is the insulating toner specified in the present invention, 6 is a developing bias power source, 9 is a toner cleaning member, 35 is a coating roller,
36 is a fiber brush fixed to the surface thereof, and 40 is a bias power source for application. The toner 5 is rotated by the application roller 35, conveyed by the brush 36, uniformly applied onto the toner carrier 2, and then jumped to the electrostatic image of the electrostatic image carrier 1 to be developed. The gap between the toner carrier 2 and the coating roller 35 is adjusted so as to form a uniform toner layer of about 5 to 100 μm on the toner carrier 2, and a bias voltage is applied by the coating bias power supply 40 for uniform toner coating. May be applied. The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the toner layer thickness, and a developing bias may be applied from the developing bias power source 6 at the time of development.

FIG. 4 is another example of the embodiment. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, 5 is a one-component toner specified in the present invention, 43 is a developing device, 48 is a magnetic roller,
Reference numeral 49 is the non-magnetic sleeve, 50 is a magnet, 52 is a magnetic brush, and 53 is a one-component toner or a two-component developer in which a toner and a magnetic carrier are mixed. Non-magnetic sleeve 4
The toner or developer 53 is drawn up by the carrier brush and contact-coated on the toner carrier 2 by rotating the sleeve 49 which is made into a brush by holding the magnetic carrier on the magnetic carrier 9 with a magnetic force to form a uniform toner layer. 5 is formed. At that time, the carrier is magnetically attracted to the magnetic roller 48.
Since it is held above, it does not move onto the toner carrier 2. Next, flight development is carried out from the toner carrier 2 onto the electrostatic image carrier 1. The gap between the magnetic roller 48 and the toner carrier 2 is adjusted so that the thickness of the toner layer on the toner carrier 2 is about 5 to 100 μm. Toner carrier 2 and electrostatic image carrier 1
The developing bias voltage may be applied to the toner carrier 2 by making the gap between and larger than the toner layer thickness.

FIG. 5 is a diagram showing another example of the embodiment. In the figure, 1 is an electrostatic image carrier, 2 is a toner carrier, 3 is a hopper, 6 is a developing bias power source, 5 is a one-component toner specified in the present invention, 50 is a fixed magnet, and 52 is a carrier toner mixture. A magnetic brush 58 is a toner thickness regulating blade. Magnetic brush 52 formed on the toner carrier 2
Is circulated by rotating the toner carrier 2, and the toner in the hopper 3 is taken in to coat the toner carrier 2 uniformly in a thin layer. Next, the toner carrier 2 and the electrostatic image carrier 1 are played with a gap larger than the toner layer thickness, and the one-component toner 5 on the toner carrier 2 is fly-developed onto the electrostatic image on the electrostatic image carrier 1. Let The thickness of the toner layer is controlled by the size of the magnetic brush 52, that is, the carrier amount and the regulation blade 58. The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the toner layer thickness and a developing bias may be applied from the bias power source 6.

Example 1 A positively chargeable toner (average particle size 10 μm) having the following composition was prepared.

On the other hand, a mixture of 100 parts by weight of liquefied zinc, 20 parts by weight of styrene-butadiene copolymer, 40 parts by weight of n-butyl methacrylate, 120 parts by weight of toluene and 4 parts by weight of 1% methanol solution of rose bengal was dispersed in a ball mill for 6 hours. Mixed. This was applied to a 0.05 mm thick aluminum plate with a wire bar so that the dry coating thickness was 40 μm, and the solvent was evaporated with warm air to prepare a zinc oxide binder type photoreceptor, which was formed into a drum shape. This photoreceptor was left at -6 kV corona, uniformly charged over the entire surface, and then irradiated with the original image to form an electrostatic latent image. The toner was put into a developing device as shown in FIG. 1 to develop the electrostatic latent image formed above. In this case, the toner carrier 2 is a stainless steel cylindrical sleeve having an outer diameter of 50 mm, and the distance between the photosensitive drum surface and the sleeve surface is set to 0.25 mm, and the sleeve is 400 Hz.
An AC of 1000V and a DC bias of -150V were applied.

Then, the powder image was transferred while irradiating a DC corona of -7 kV from the back surface of the transfer paper to obtain a captured image. The fixing was performed using a commercially available plain paper copying machine (trade name, NP-5000, manufactured by Canon).

The obtained transferred image had a sufficiently high density, had no fog, had no toner scattering around the image, and was a good image with high resolution. Durability was continuously examined using the above toner, but the transferred image after 10,000 sheets was also an image without any amber compared with the initial image. Further, when the environmental conditions were 35 ° C. and humidity 35%, the image density was almost the same as normal temperature and normal humidity, no fog or scattering, a clear image was obtained, and the durability was hardly changed up to 10,000 sheets. Next, when a transferred image was obtained at a low temperature and low humidity of 10 ° C. and a humidity of 10%, the image density was high, and the solid black portion was developed and transferred extremely smoothly, and was an excellent image with no scattering or voids. Copies were made continuously and at intervals under these environmental conditions, but the density fluctuation was ± 0.
2 was sufficient for practical use.

Further, the toner of Example 1 was put into the apparatus shown in FIG. 2, and the vibrating member 16 was vibrated at a frequency of about 50 Hz and an amplitude of 0.2 mm.
When the toner carrier 2 is rotated at a peripheral speed of 120 mm / sec, a uniform toner coating layer having a thickness of about 50 μ is formed on the toner carrier, and a gap of about 300 μ is formed between the toner carrier 2 and the electrostatic image carrier 1. The toner carrier 2 is held opposite to each other with a frequency of 10
0-several kilohertz Hz, negative peak value -660-1200
When development was performed by applying a bias AC electric field of V and a positive peak value of +400 to +800 V, the same good result was obtained.

In addition, the toner shown in Example 1 is used in which the gap between the toner holder 2 and the coating roller 35 is about 2 mm, and the length of the fiber brush 36 is about 3 mm.
Then, the gap between the developing roller and the electrostatic image carrier is kept at 300μ, and a toner layer of about 80μ is formed on the developing roller to form an AC waveform having a frequency of 200Hz. DC component-2 at peak value ± 450V
50V added, peak voltage -700V and +20
When development was performed by applying 0 V, the same good result was obtained.

Further, 20 g of the toner of Example 1 was mixed with 20 g of the iron powder carrier in advance, and the mixture was put into the developing device shown in FIG. 5, which was set so that the gap between the regulating blade 58 and the toner carrier 2 was about 250 μ, The gap between the developing roller and the electrostatic image carrier is kept at 300μ, a toner layer of about 80μ is formed on the developing roller, and an AC waveform is formed. The same good results were obtained when the development was performed by applying the peak values of -700V and + 200V.

Example 2 A positively chargeable toner (average particle size 9 μm) having the following composition was prepared, placed in the developing device shown in FIG. 1, and carried out in the same manner as in Example 1 to obtain the same good result.

In addition, the toner of the second embodiment is applied to the toner carrier 2 and the magnetic roller 48.
And the magnetic brush 52 is set to have a maximum thickness of about 3 mm, and the magnetic brush 52 is placed in the developing device shown in FIG.
When a toner layer of 0 μ was formed on a developing roller and an AC waveform was applied, a DC component of −250 V was added to a peak value of ± 200 V at a frequency of 200 Hz, and a peak voltage of −700 V and +200 V was applied to develop the toner. The results were obtained.

Example 3 A positively chargeable toner (average particle size 10 μm) having the following composition was prepared, placed in the developing device shown in FIG. 1, and carried out in the same manner as in Example 1 to obtain the same good result.

Example 4 A positively chargeable toner (average particle size 10 μm) having the following composition was prepared, placed in the developing device shown in FIG. 2 and carried out in the same manner as in Example 1, and the same good result as in Example 1 was obtained. .

As described above, the toner containing the lake pigment of the diphenylmethane dye has a high triboelectric chargeability, and toners such as red and brown can be obtained without impairing the color tone.

Further, an electrostatic image holding member for holding the toner, in particular, an electrostatic image on the surface, and a toner holding member for holding the toner on the surface are arranged in the developing unit with a constant gap, and an external magnetic field 500 is provided.
Used for a developing method in which a toner having a saturation magnetization of 10 emu / g or less at 0 Oe is carried on a toner carrier to a thickness smaller than the gap, and the toner is transferred to the electrostatic holder at a developing section. In this case, the durability against repeated continuous copying is good, and there are advantages such that stable quality images can be produced for a long period of time.

[Brief description of drawings]

1, FIG. 2, FIG. 3, FIG. 4, and FIG. 5 are sectional views showing different forms of the developing device used for carrying out the developing method according to the present invention. 1 ... Electrostatic image carrier, 2 ... Toner carrier 3 ... Hopper, 4 ... Toner application means 5 ... One-component non-magnetic toner, 6 ... Development bias power source 9 ... Toner cleaning blade 10 ... Toner supply member, 35 ... Coating roller 36 ... Fiber brush, 40 ... Coating bias power source 48 ... Magnetic roller, 49 ... Non-magnetic sleeve 50 ... Permanent magnet, 52 ... Magnetic brush 53 ... One component Non-magnetic toner or two-component developer in which magnetic carrier and magnetic carrier are mixed.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takeshi Ikeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Eiichi Imai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (56) References JP-A-52-113738 (JP, A) JP-A-52-60624 (JP, A)

Claims (1)

[Claims] 1. A positively chargeable toner composition, characterized in that a binder resin contains a pigment in which a dye represented by the following general formula is laked. [Wherein R ₁ , R ₂ , R ₄ and R ₅ are independently hydrogen,
And a lower alkyl group which may be substituted with a hydroxyl group or an alkoxy group, wherein R ₃ and R ₆ are each independently hydrogen, a phenyl group, a hydroxyl group, or a lower alkyl group which may be substituted with an alkoxy group; Group, R ₇ represents a phenyl group, and A ⁻ represents an anion.