JPS60196774A - Positive electrifiable toner composition - Google Patents

Abstract

PURPOSE:To decrease dependency of a toner/carrier ratio on a change in total amt. of a developer, etc. and to improve environmental stability and continuous use characteristics by incorporating a pigment formed by laking a specific diphenyl methane dye into a binder resin. CONSTITUTION:A pigment made by laking the diphenyl methane dye expressed by the formula (R1, R3 are respectively H, phenyl, hydroxyl group, etc., R2, R4 are respectively H, lower alkyl, etc., X1, X2 are respectively H, halogen lower alkyl, etc., A<-> is anion) is incorporated into a binder resin. The toner incorporated with such pigment has high friction electrification and good durability to repeated continuous copying. A developing method consisting in disposing an electrostatic image holding body 1 and a toner carrier body 2 at a specified space in a developing part, depositing a toner 5 having <=10emu/g satd. magnetization in about 5,000 Oe external magnetic field on the body 2 to the thickness smaller than the above-mentioned space and transferring the toner to the body 1 is used, by which the image having the image quality remaining stable even in the environment of high temp. and high humidity or low temp. and low humidity is obtd. over a long period of time.

Description

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

Conventionally, developing methods for electrophotography, electrostatic recording, etc. are broadly classified into dry developing methods and wet developing methods. The former is
The method is further divided into two types: a method using a two-component developer and a method using a -component developer.

Two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, etc., depending on the type of carrier that transports the toner.

One-component developing methods include the dark cloud method, in which toner particles are used in a spray state, and the contact development method, in which toner particles are brought into direct contact with the latent image surface for development. (Also referred to as toner development), a zoyambing development method in which toner particles are not brought into direct contact with the electrostatic latent image surface, but are charged and flown toward the latent image surface by the electric field of the electrostatic latent image; There is a magneto-dry method in which a conductive toner is brought into contact with an electrostatic latent image surface for development.

In the two-component development method, a mixed developer of carrier particles and toner particles is inevitably used, and as the development process normally progresses, the toner particles are consumed in a much larger amount than the carrier particles, so the mixing ratio of the two is This inherently has drawbacks such as the density of the image being changed and the quality of the image being degraded due to deterioration of carrier particles that are difficult to consume due to long-term use.

On the other hand, in -component type development methods, in the MagneDry method using magnetic toner and the contact development method not using magnetic toner, the toner contacts the entire surface of the surface to be developed, that is, the image area and the non-image area, indiscriminately. As a result, the toner easily adheres to non-image areas, resulting in so-called smudging and staining (this capri smudging is a drawback that also occurs in two-component developing methods). Ta). or,
Even in the powder cloud method, it is unavoidable that powdered toner particles adhere to non-image areas, and the powder cloud method also has the disadvantage that it is impossible to remove the adhesive particles.

In this regard, JP-A-54-43027, JP-A-55-
18656, etc., an electrostatic image holder that holds an electrostatic image on its surface and a toner carrier that carries an insulating toner on its surface are installed with a certain gap in the developing section, and the toner is The method of developing is to carry the toner on the toner carrier in a thinner thickness than the gap, and transfer the toner to the electrostatic image carrier in the developing section. It has the advantage of being less prone to fogging.

Furthermore, since carrier particles are not used, there is no variation in the mixing ratio as described above, and there is no deterioration of the carrier particles, making it an electrostatic image developing method with high fidelity and stable image quality. However, a problem with this method is that it is necessary that the toner layer on the toner carrier be uniform39; otherwise, uneven density and dryness may occur in the image, resulting in an unsightly image. Therefore, in order to improve the transportability of the toner on the toner carrier, magnets are placed in the toner carrier to use toner containing a magnetic material. Although it is possible to obtain a layer coat relatively stably, problems such as deterioration of fixing properties, damage to the photoreceptor, increased visibility, and deterioration of the hue of chromatic toners may occur because the toner contains a magnetic material. There is.

Therefore, an electrostatic image carrier that holds an electrostatic image on its surface and a toner carrier that carries toner on its surface are arranged with a certain gap in the developing section, and the saturation magnetization is 1 oemul/1 in an external magnetic field of 50,000e. A developing method may be considered in which a toner weighing less than g is supported on a toner carrier in a thickness thinner than the gap, and the toner is transferred to the electrostatic holding member in a developing section.

With this method, not only can the advantages of one-component jumbling development be taken advantage of, but also the toner can be neatly coated on the toner carrier regardless of the presence or absence of a magnetic substance in the toner. However, due to changes in the total amount of developer, it may not always be possible to uniformly charge the toner, which is likely to result in poor toner coating conditions.

However, positive charge control agents used in such dry developing toners generally include, for example, quaternary ammonium compounds and conservative dyes, particularly basic dyes and their salts. Common positive charge control agents include pendylmethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, nigrosine base, nigrosine, safranin gamma and crystal pimelet. % of nigrosine base and nigrosine is often positively charged 1'Bi
It is used as a medicine for JIILJ. These are usually added to thermoplastic resins, thermally melted and dispersed, and then finely pulverized and adjusted to a suitable particle size as necessary before use.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability. However, it is still susceptible to decomposition or deterioration due to decomposition during thermal kneading, mechanical impact, friction, changes in temperature and humidity conditions, etc., and it is easy to cause phenomena that reduce charge controllability.

Therefore, when a toner containing these dyes as a charge control agent is developed using a copying machine, as the number of copies increases, the charge control agent decomposes or changes in quality, which may cause deterioration of the toner during durability.

Furthermore, many of the substances generally known to be positively chargeable have a dark color and cannot be incorporated into a bright chromatic developer.

Furthermore, since it is extremely difficult to uniformly disperse these positive charge control agents in a thermoplastic resin, they have the fatal drawback of causing a difference in the amount of frictional charge between toner particles obtained by pulverization. are doing. For this reason, various methods have been used to achieve more uniform dispersion. For example, basic nigrosine dyes are used by forming salts with higher fatty acids in order to improve their compatibility with thermoplastic resins, but often unreacted fatty acids or salt dispersion products are
It is exposed on the toner surface and contaminates the carrier or toner carrier, causing a decrease in the fluidity of the toner, fogging, and a decrease in image density. Alternatively, in order to improve the dispersion of these charge control agents into the resin, a method has also been adopted in which charge control agent powder and resin powder are mechanically pulverized and mixed in advance and then hot melt-kneaded. but,
The inherent poor dispersion cannot be avoided, and the current situation is that sufficient uniformity of charge has not yet been achieved for practical use.

In addition, many positive charge control agents are hydrophilic, and due to poor dispersion in these resins, when pulverized after melting and mixing,
The dye is exposed on the toner surface. Therefore, when the toner is used under high humidity conditions, it has the disadvantage that although these charge control agents are hydrophilic, good quality images cannot be obtained.

In this way, when a conventional positive charge control agent is used in a toner, it can be applied to the toner particle surface between toner particles, between a toner and a carrier, or between a toner and a toner carrier such as a sleeve. The amount of charge generated is uneven, and problems such as development capri, toner scattering, and carrier contamination are likely to occur. Furthermore, this problem becomes more noticeable when a large number of copies are made, and the result is that the copying machine is not suitable.

Furthermore, under high humidity conditions, the transfer efficiency of toner images decreases significantly, and many of them become unusable. Even at room temperature and humidity, when the toner is stored for a long period of time, it often becomes unusable due to the instability of the positive charge control agent used.

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

That is, an object of the present invention is to provide a positively chargeable toner that is less dependent on changes in the toner to carrier ratio, the total amount of developer, and the like.

That is, an object of the present invention is to provide a positively chargeable toner that is inferior in 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.

The feature of the present invention resides in a positively chargeable toner composition characterized in that the binder resin contains a pigment obtained by forming a diphenylmethane dye represented by the following general formula into a lake.

However, in the formula, R1yR11 each independently represents hydrogen, a phenyl group, a hydroxyl group, or a lower alkyl group which may be substituted with an alkoxy group, or a phenyl group, and B-2e R4
each independently represents a lower alkyl group which may be substituted with hydrogen or a phenyl group, a hydroxyl group, or an alkoxy group; They independently represent hydrogen, halogen, lower alkyl group, or lower alkoxy group, and A- represents an anion.

Examples of diphenylmethane dyes used in the present invention include the following.

Lake formation of the above dye is carried out by a known method.

For example, an aqueous solution of a lake forming agent is added to an aqueous solution of a dye in acetic acid to precipitate a lake pigment. Alternatively, the extender pigment is suspended in an acetic acid aqueous solution of the dye, and then an aqueous solution of a lake forming agent is added to deposit the lake pigment on the surface of the extender pigment. The lake pigment is filtered, washed with water, and then dried. Examples of the lake-forming agent include water-soluble salts of syntungsten molybdic acid, syntungstic acid, and synmolybdenum, and water-soluble salts containing complex ions such as ferrocyan and ferricyan.

Organic acid salts can also be used as lake forming agents, but gallic acid lakes, for example, do not have very good charging properties. This is thought to be because, in the case of an organic acid lake, since the resin and the lake have good compatibility, the property of the resin having poor charging characteristics becomes noticeable.

The developing method using the toner composition of the present invention includes:
An electrostatic image carrier that holds an electrostatic image on its surface and a toner carrier that carries toner on its surface are arranged with a certain gap in the developing section, and the saturation magnetization l in an external magnetic field of 5000 ()e A developing method is preferred in which a toner having a Q am u/9 or less is supported on a toner carrier to a thickness thinner than the gap, and the toner is transferred to the electrostatic holder in a developing section.

The present inventors used the above development method to study various conventionally known non-magnetic or weakly magnetic toners, and found that in order to solve the above-mentioned drawbacks, compared to the development method using magnetic toner, We have found that it is important to precisely control the amount of electrostatic charge held by the toner on the toner carrier in the developing section. That is, in a developing method using insulating non-magnetic toner, for example, if the amount of charge is low, the toner will not be applied uniformly on the toner carrier, and development will not be possible. If the value is not appropriate even if the value is not appropriate, background fog will easily occur, and conversely, if the value is too high, the electrostatic attraction with the toner carrier will be too strong and the toner will not retain the electrostatic image. It becomes difficult to metastasize to the body, resulting in a decrease in image density and the appearance of low-quality images. Furthermore, for the same reason, the quality of the image is greatly affected by changes in the toner load caused by recombination or environmental changes. Therefore, it is extremely important to ensure the stability of the amount of charge. In addition, the physical adhesion force between the toner and the toner carrier clearly affects the transfer of the toner from the toner carrier, for example, the degree of freedom of each toner is small and the toner is applied in a single layer of toner on the toner carrier. If the density is high, the image density will be low, resulting in a low-quality image with low resolution, so it is also important to prevent the physical adhesion from increasing.

As a result of extensive research, the present inventor has found that when a toner contains a lake pigment of a nophenylmethyl dye represented by the general formula as described above, an electrophotographic toner exhibiting various excellent properties can be obtained. I found out. Furthermore, we have found that it is very effective to apply this developer to the above-mentioned developing method.

That is, a toner containing a diphenylmethane-based dye lake pigment has high triboelectric charging properties and good durability against repeated continuous copying, and when applied to the above development method, it can be used in high temperature and high humidity environments, and in low temperature and low humidity environments. It is now possible to produce images with stable image quality over a long period of time even at low temperatures.

In the present invention, methods for incorporating the diphenylmethane lake pigment into the toner include a method of adding it inside the developer and a method of adding it externally. When internally added, the content of the control agent is 0.1 to 50 v for 100 wt96 of resin.
t% is desirable, and 0.5 to 20 wt% is particularly desirable. In addition, when adding externally, resin 100 wt.
%, preferably 0.01 to 40 wt%, especially 9
．． 05 to 10 wt% is highly desirable.

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

For example, the issue? Styrenic copolymers such as listyrene, polystyrene/butadiene copolymer, styrene/acrylic copolymer, ethylene copolymers such as I-lyeethylene, polyethylene vinyl acetate copolymer, polyethylene vinyl alcohol copolymer, and phenolic copolymers. resin, epoxy resin,
These include allyl phthalate resin, polyamide resin, polyester resin, maleic acid resin, etc. Furthermore, there are no particular restrictions on the manufacturing method of any of the resins. This is because conventionally, resins produced by emulsion polymerization or the like tend to contain impurities and are difficult to use, but the present invention allows them to be used easily, 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.

Further, 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 material that can be magnetized may be used, such as iron.

Fine powders of metals such as manganese, nickel λ, cobalt, and chromium, magnetite, various ferrites, manganese alloys, and other ferromagnetic alloys can be used.

Hereinafter, the use of the toner of the present invention will be explained in detail using embodiment diagrams.

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 on which an electrostatic latent image is formed, for example, by a known electrophotographic method such as the Carlson method or the NP method. The insulating toner 5 is applied onto the toner carrier 2 by a coating means 4 that controls the thickness of each toner layer and is applied to the toner 5 for development.

The toner carrier 2 is a cylindrical developing roller made of stainless steel. 1 Aluminum may be used as the material for this developing roller, or other metals may be used. Alternatively, a metal roller coated with resin or the like may be used in order to frictionally charge the toner to a desired polarity. Additionally, the developer roller may be made of an electrically conductive non-metallic material. Although not shown, spacer rollers made of high-density polyethylene are inserted into the shafts of the toner carrier 20 at both ends thereof. By applying these spacer rollers to both ends of the electrostatic image holder 10 and fixing the developing device, the distance between the electrostatic image holder 1 and the toner carrier 2 can be adjusted so that the toner coated on the toner carrier 2 can be Set and maintain the thickness of one layer or more. This interval is, for example, 100μ to 500μ.

Preferably it is 150μ to 300μ. If this distance is too large, the electrostatic latent image on the electrostatic image carrier 1 will not be as strong as the non-magnetic toner applied on the toner carrier 2, and the electrostatic force will be weak, resulting in poor image quality, especially in the development of side lines. visualization becomes difficult. Moreover, if this interval is too narrow, the toner applied on the toner carrier 2 will be mixed with the toner carrier 2 and the electrostatic image carrier 1.
There is a great danger that the material will be compressed and agglomerated between the two.

Reference numeral 6 denotes a developing bias power source, which is capable of applying a voltage between the conductive toner carrier 2 and the back electrode of the electrostatic holder 1. This developing bias voltage is
This is the developing bias voltage as described in No. 08.

FIG. 2 is another example of the embodiment. In the same figure, 1
2 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,
10 indicates a toner supply section.

16 is a vibration member, 17 is a vibration generating means, 6a is a permanent magnet, 16b is a support spring, 17a is a core, and 17b is a winding. By applying an alternating current to the winding 17b, the vibrating member 16 is vibrated at an appropriate amplitude and frequency, and a uniform toner coating layer is formed on the toner carrier 2 which is rotating at a constant speed, thereby separating the toner carrier 2 and the electrostatic image. The electrostatic image is developed by making the non-magnetic toner fly onto the electrostatic image by opposing the holder 1 with a gap larger than the thickness of the toner coating layer. The vibration of the vibrating member 16 may be at any level as long as it does not come into direct contact with the toner carrier 2, but it is preferable to control the frequency and amplitude so that the toner coating layer has a uniform thickness of about 5 to 100 μm. .

Also, an alternating current or/and
It is also possible to apply a direct current developing bias voltage.

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 developer container, 5 is an insulating toner specified in the present invention, 6 is a development bias power source, 9 is a toner cleaning member, 35 is an application roller, 3
Reference numeral 6 indicates a fiber brush fixed to the surface thereof, and reference numeral 40 indicates a bias power source for application. The application roller 35 is rotated, and the toner 5 is conveyed by a brush 36 to be uniformly applied onto the toner carrier 2, and is caused to fly onto the electrostatic image on the electrostatic image holder 1 for development. The gap between the toner carrier 2 and the application roller 35 is adjusted so as to form a uniform toner layer of about 5 to 100 μm on the toner carrier 2, and the bias voltage is set by the application bias power supply 40 to uniformly apply the toner. may be applied. The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the thickness of the toner, and a developing bias may be applied by a developing bias power source 6 during 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 the monocomponent toner specified in the present invention, 43 is a developer, 48 is a magnetic roller,
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
By holding the magnetic carrier on the toner carrier 9 by magnetic force and turning it into a blank, and rotating the sleeve 49, the toner or developer 53 is drawn up with the carrier brush and is uniformly coated on the toner carrier 2 by contacting it. A single toner layer 5 is formed. At this time, since the carrier is held on the magnetic roller 48 by magnetic force, it does not move onto the toner carrier 2. Next, the toner is developed by flying from the toner carrier 2 onto the electrostatic image holder 1.

The gap between the magnetic roller 48 and the toner carrier 2 is adjusted so that the thickness of each layer of toner on the toner carrier 2 is about 5 to 100 μm. The gap between the toner carrier 2 and the electrostatic image holder l may be made larger as the thickness of the toner increases, and a developing bias voltage may be applied to the toner carrier 2.

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, and 3 is a toner carrier.
1 is a hopper, 6 is a developing bias power source, 5 is a monocomponent toner specified in the present invention, 50 is a fixed magnet, 52 is a magnetic brush made of a carrier toner mixture, and 58 is a blade for regulating toner thickness. The magnetic brush 52 formed on the toner carrier 2 is circulated by rotating the toner carrier 2, and the toner in the toner 4-3 is poured into the toner carrier 2.
Apply a thin layer evenly on top. Next, the toner carrier 2 and the 11p' image carrier 1 are placed in opposition with a larger gap than the thickness of the toner, so that the one-component toner 5 on the toner carrier 2 is transferred onto the electrostatic charge image on the electrostatic image carrier 1. Perform flying development. The thickness of one layer of toner is controlled by the size of the magnetic brush 52, that is, the amount of carrier, and the regulating blade 58.

The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the thickness of the toner, and a developing bias may be applied from the bias power source 6.

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

On the other hand, a mixture consisting 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 Rose Bengal 1-thimethanol solution was dispersed in a ball mill for 6 hours. Mixed. This was applied to an aluminum plate with a 0.05 fin thickness using a wire bar so that the dry coating thickness was 40 μm, and the solvent was evaporated with warm air to produce a zinc oxide binder-based photoreceptor in the form of a drum. 16kV to this photoconductor
After corona discharge was performed to uniformly charge the entire surface, an original image was irradiated to form an electrostatic latent image. The toner was placed in a developing device as shown in FIG. 1, and the electrostatic latent image formed above was developed. In this case, the toner carrier 2 is a stainless steel cylindrical sleeve with an outer diameter of 50 m, the photosensitive drum surface-to-sleeve surface ratio is set to #0.25 mm, and the sleeve is applied with an alternating current of 400 Hz, 1000 V, and a direct current bias of -150 mm. applied.

Next, the powder image was transferred while irradiating the back surface of the transfer paper with a direct current corona of p -7 kV to obtain a copied image. Fixing was carried out using a commercially available plain paper copying machine (trade name: NP-5000, manufactured by Canon).

The resulting transferred image had a sufficiently high density, no fogging, no toner scattering around the image, and was a good image with high resolution. Durability was continuously examined using the above toner, and the transferred image after 10,000 copies was also completely dull compared to the initial image. In addition, when the environmental conditions were set to 35℃ and humidity to 85℃, the image density was almost the same as normal temperature and humidity, and there was no fogging or scattering, clear images were obtained, and the durability was almost unchanged up to 100 pages. Ta. Next, a transferred image was obtained at a low temperature and low humidity of 10 degrees Celsius and 10 inches of humidity, and the image density was high, even the black areas were developed and transferred extremely smoothly, and the image was excellent without any scattering or hollow spots. I made continuous copies under these environmental conditions and the density fluctuation was ±0 up to 10,000 copies.
2 was enough soil.

When the toner of Example 1 is put into the apparatus shown in FIG. 2, the vibrating member 16 is vibrated at a frequency of about 50 Hz and an amplitude of 0.2-, and the toner carrier 2 is rotated at a circumferential speed of 120 mm and 1 NIe, the toner is released. A uniform toner coating layer with a thickness of about 50 μm is formed on the carrier, and the toner carrier 2 and the electrostatic image carrier 1 are coated with a uniform toner coating layer of about 30 μm thick.
A frequency of 100 to several kilohertz is applied to the toner carrier 2 while facing each other with a gap of 0 μ.

Similar good results were obtained when development was performed by applying a bias AC electric field with a negative peak value of -660 to -1200V and a positive peak value of +400 to +800V.

The toner shown in Example 1 was applied to the toner holder 2 and the application roller 3.
The gap between the fiber brushes 36 and the length of the fiber brush 36 was set to about 2 mm, and the length of the fiber brush 36 was set to about 3 mm. As shown in Fig. 3, the toner was loaded into the developing device, developed, and the gap between the roller and the electrostatic holder was kept at 300μ, and a single layer of approximately 80μ was formed on the developing roller, and the peak of the voltage at a frequency of 200 Hz was generated as an AC waveform. By adding the DC component -250V to the value ±450V, the voltage peak value near 00V and +
Similar good results were obtained when a voltage of 200V was applied for development.

20 g of the toner of Example 1 is mixed with the iron powder carrier 20p in advance, and the mixture is transferred to the regulating blade 58 and the toner carrier 2.
5, which is set so that the gap between the developing roller and the electrostatic image holder is approximately 250μ, and the gap between the developing roller and the electrostatic image holder is set to 3.
A single layer of toner of about 80μ was formed on the developing roller, and as an AC waveform, a DC component of -250V was added to the peak voltage of 50V at a frequency of 200 Hz, and the peak value of the voltage was -700V and +200V. Similar good results were obtained when the film was developed using the following conditions.

Example 2 A toner (average particle size 9μ) having the following composition was prepared, and M
The sample was placed in a developing device as shown in FIG. 1 and carried out in the same manner as in Example 1, and similar good results were obtained.

The toner of Example 2 was put into the developing device shown in FIG. 4, which was set so that the gap between the toner carrier 2 and the magnetic roller 48 was about 2 mm, and the maximum thickness of the magnetic brush 52 was about 3 wn. Keep the gap between the cap and the electrostatic holder at 300μ, and
When a single layer of μ toner was formed on the developing roller and developed with an AC waveform, a DC component of -250V was added to the peak value of the voltage at a frequency of 200Hz, ±450V, and voltage peak values of -700V and +200V were applied, the same good results were obtained. The results were obtained.

Example 3 A toner (average particle size 10μ) having the following composition was prepared,
The sample was placed in the developing device shown in FIG. 1 and carried out in the same manner as in Example 1, and similar good results were obtained.

Example 4 A toner (average particle size 10μ) having the following composition was prepared,
When the sample was placed in the developing device shown in FIG. 2 and subjected to the same procedure as in Example 1, good results similar to those in Example 1 were obtained.

As explained above, the toner containing the nophenylmethane dye lake pigment has (1) high triboelectric charging properties; ■ Without losing color tone,
Yellow, orange, etc. toners are obtained.

Furthermore, an electrostatic image carrier that holds an electrostatic image on the surface of this toner, and a toner carrier that carries the toner on its surface are arranged with a certain gap in the developing section, and are exposed to an external magnetic field 50.
A developing method in which a toner having a saturation magnetization of 10 emu/I or less at 000e is supported on a toner carrier to a thickness as thin as the gap, and the toner is transferred to the electrostatic holding member in a developing section. When used for this purpose, it has the following advantages: (1) It has good durability against repeated continuous copying and can produce images with stable image quality over a long period of time.

[Brief explanation of drawings]

FIGS. 1, 2, 3, 4, and 5 are cross-sectional views showing different forms of the developing device used to carry out the developing method according to the present invention. 1... Electrostatic image holder 2... Toner carrier 3...
Hola... 9 4... Toner application means 5... - Component non-magnetic toner 6... Development bias weight 9... 1 l - Even! J-Ninkfrede 10... Toner supply member 35-1... Application roller 36... Fiber brush 40... Application bias power source 48... Magnetic roller 49... Non-magnetic sleeve 50
. . . Permanent magnet 52 . . . Magnetic brush 53 . . . -component non-magnetic toner or a two-component developer consisting of a mixture of non-magnetic toner and magnetic paint 58 . . . Regulating blade Fig. 1 Fig. 2 Fig. 3 Fig. 40 Figure 5

Claims (1)

[Claims] A positively charging toner composition characterized in that the binder resin contains a laked pigment of a diphenylmethane dye represented by the following general formula. However, in the formula, R1+83 each independently represent hydrogen, a phenyl group, A lower alkyl group which may be substituted with a hydroxyl group or an alkoxy group, a phenyl group, R
2゜R4 each independently represents a lower alkyl group which may be substituted with hydrogen, a hydroxyl group or an alkoxy group,
1 +
It represents a lower alkoxy group, and 8- represents an anion.