JP2670459B2 - Positively chargeable toner - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel positively chargeable toner for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like.

(Prior art)

Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 (U.S. Pat.No. 3,666,363), and Japanese Patent Publication No. 43-24748 (U.S. Pat.
Numerous methods are known, for example, Japanese Patent Application Laid-Open No. 61 (1994). Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed using a toner or a developer, and if necessary, a transfer material such as paper. After the transfer of the toner image to the toner image, the toner image is fixed by a heat, pressure, pressure and heat roller or a solvent vapor to obtain a copy.
In the case where a step of transferring a toner image is provided, a step for removing residual toner on the photoconductor is usually provided.

A developing method for visualizing an electric latent image using toner is as follows.
For example, the magnetic brush method described in U.S. Pat.No. 2,874,063, the cascade developing method described in U.S. Pat.No. 2,618,552 and the powder cloud method described in U.S. Pat.No. 2,221,776, U.S. Pat. A method using a conductive magnetic toner described in the specification is known.

Conventionally, fine powders obtained by dispersing dyes and pigments in natural or synthetic resins have been used as toners applied to these developing methods. For example, particles obtained by finely pulverizing a dispersion of a colorant in a binder resin such as polystyrene to about 1 to 30 μm are used as toner. A magnetic toner containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually used by being mixed with carrier particles such as glass beads and iron powder.

In order to retain charge in the toner, it is possible to use the triboelectricity of the resin which is a component of the toner.However, in this method, since the toner has a small chargeability, an image obtained by development is easily fogged and unclear. It will be. Accordingly, in order to impart a desired triboelectric charging property to the toner, a dye, a pigment for imparting the charging property, and a charge controlling agent have been added.

Among the charge control agents known in the art today, a positive charge control agent is a nigrosine dye (Japanese Patent Publication No.
No. 2427), azine dyes (Japanese Patent Publication No. 42-1627), amino group-containing vinyl polymers and condensation polymers (Japanese Patent Publication No. 53-13284), quaternary ammonium salts (Japanese Patent Laid-Open No. 62-62284). -192755, JP-A-62-87974 and JP-A-62-53944).

On the other hand, the charge control agent must have a sufficient amount of triboelectric charge, have little environmental change in the amount of triboelectric charge, have good storage stability, have good thermal stability, and have good dispersibility in the binder resin. However, none of the conventionally known charge control agents satisfy all of these requirements.

Also, JP-B-57-3940, JP-B-58-9415, JP-A-54-84732, JP-A-56-46248,
Japanese Unexamined Patent Publication No. 61-124955 discloses that a triphenylmethane dye and a pigment obtained by laking this dye can be favorably used in a two-component non-magnetic toner.

However, many of these triphenylmethane dyes or laked pigments have low triboelectric charges and cannot be used for magnetic toners. Further, there are triphenylmethane dyes and lake pigments having a sufficient triboelectrification amount, but toners using these are liable to contaminate a toner carrier such as a sleeve and easily cause fog.

Furthermore, it was found that even in the triphenylmethane skeleton, there is a difference in charge stability when formed into a toner depending on the conjugated state, and a developer containing a positive charge control agent showing a specific state of the present invention was invented. It was

[Problems to be solved by the invention]

An object of the present invention is to provide a positively chargeable toner that solves the above problems.

A further object of the present invention is that the triboelectric charge amount is stable, and
It is an object of the present invention to provide a positively chargeable toner having a triboelectric charge amount distribution which is sharp and uniform and which can be controlled to a charge amount suitable for the developing system used.

Still another object is to provide a positively chargeable toner that reproduces a stable image without causing defects such as background fog and image density reduction.

Still another object is to provide a positively chargeable toner capable of maintaining the initial characteristics even when the developer is continuously used for a long period of time.

Still another object is to provide a positively chargeable toner that reproduces a stable image that is not affected by changes in temperature and humidity.

Still another object is to provide a positively chargeable toner which is excellent in storage stability and retains initial properties even after long-term storage.

[Summary of the Invention]

 That is, the present invention includes at least a binder resin, a colorant, and
And a positively chargeable toner containing a positively chargeable control agent, wherein the positively chargeable control agent has the following formula:[Where R₁, R_TwoAnd R_ThreeAre the same or different
Is a group which may be a hydrogen atom, a halogen atom, an alkyl
A group or an alkoxy group, A Represents an anion. A compound having a basic skeleton represented by the formula: wherein the compound in the toner has an infrared absorption spectrum
1500 ± 10 cm^-1Absorption peak T of_(A)And 1575 ± 10 cm^-1Sucking
Peak T_(B)Ratio with (T_(A)/ T_(B)) Is 0.1 to 0.5,
And 1340 ± 10 cm^-1Absorption peak T of_(C)And 1575 ± 10 cm^-1Sucking
Peak T_(B)Ratio with (T_(C)/ T_(B)) Is 1.0 to 0.6
And a positively chargeable toner.

 A Is preferably halogen ion, sulfate ion, glass
Acid ion, borate ion, phosphate ion, hydroxyl ion,
Organic Sulfate Ion, Organic Sulfonate Ion, Organic Phosphate I
On, carboxylate ion, organic borate ion, tetraf
Shows anions such as luoroborate.

[Detailed Description of the Invention] As a result of studies to achieve the above-mentioned object, the present inventors have shown by the above general formula [I] having a transmittance ratio of a specific infrared absorption spectrum in the toner. The triarylmethane derivative having a phenylamino group has a high positive triboelectrification amount, and since it is laked, the hygroscopicity originally possessed by the triarylmethane derivative does not adversely affect the positive triboelectrification ability. We have found that it can be improved.
Further, the toner containing the dye represented by the general formula [I] and the laked pigment contaminates a toner carrier such as a sleeve, but it can be remarkably improved by externally adding a positively chargeable silica fine powder to the toner. I found out. The present invention has been completed based on such findings.

In the present invention, examples of the compound of the charge control agent [I] having an effective basic skeleton include the following compounds.

As the alkyl group and the alkoxy group represented by R ₁ , R ₂ , and R _{3 in} the general formula [I], those having 8 or less carbon atoms are preferable in view of easiness of synthesis.

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 precipitate the lake pigment on the surface of the extender pigment. The lake pigment is filtered, washed with water and dried. Examples of the laker include phosphotungsten molybdic acid, phosphotungstic acid, water-soluble salts of phosphomolybdic acid, and water-soluble salts containing complex anions such as ferrocyan and ferriciyan. Although an organic acid salt can be used as a laker, for example, gallic acid lake does not have very good charging characteristics.
This is considered to be due to the fact that the compatibility between the resin and the lake is good in the organic acid lake, so that the properties of the resin having poor charging characteristics appear remarkably.

In the present invention, in order to fully bring out the effect of the compound having the basic skeleton represented by the general formula [I] used as the positive charge control agent, the infrared absorption spectrum of the compound in the toner is 1500 ± 10 cm. ^-1 absorption peak
T _(A) , absorption peak at 1575 ± 10 cm ^-1 T _(B) , absorption peak at 1340 ± 10 cm ^-1 T _(C) Characteristic absorption transmittance ratio is T _(A) / T _(B) = 0.1
To 0.5, T _(C) / T _(B) = 1.0 to 0.6, more preferably T _(A) / T _(B) = 0.2 to 0.45, T _(C) / T _(B) = 0.9
~ 0.6. This is considered to indicate a resonance state in the basic skeleton. That is, it is considered that 1500 cm ⁻¹ and 1575 cm ⁻¹ are based on the in-plane skeletal vibration of phenyl and the 1340 cm aromatic amine C—N stretching absorption, and they are strongly conjugated between the phenyl ring and the amine group. And progress in C-N conjugate appeared stronger C-N stretching vibration in the vicinity of 1340 cm ^-1, 1500 cm absorption near ^-1 is weakened, but the resonance stabilization and charge controlling strong very correlated It was discovered from the examination that there is. For example, T _(A) / T _(B) is
In a state where 0.5 or more and T _(C) / T _(B) is 0.6 or less, charging is unstable, image density is thin, fog is likely to increase, and T _(A) / T _(B) is When the ratio is 0.1 or less and T _(C) / T _(B) is 1.0 or more, the quaternized amine becomes unstable and the image quality and the image density are likely to deteriorate.

In the present invention, some conditions have been found to be suitable, although the reason is not clear, in order to exhibit the characteristic performance of the positively chargeable agent.

In the crystallization process, the average primary particle size is 0.05 ~ 1.0μ
m, preferably 0.1 to 0.5 μm is convenient for obtaining an appropriate electronic state.

As secondary particles, 0.1 ~ 5.0μ by the measurement method described below.
m, preferably 0.1 to 2.0 μm, and 10 μm or more is 10 wt% or less, preferably 5 wt% or less, more preferably 0 wt%.

In addition, it has been recognized that the electronic state of the surface of the positively chargeable control agent is brought to an appropriate or inappropriate state by mechanochemical or heat. For example, the spectrum of the present invention can be expressed by crushing the secondary agglomerates with a mechanical crusher, an impact crusher, a rubbing grinder, or the like. Further, it is inappropriate to apply excessive heat during toner production, and, as shown in Comparative Example 2 described later, simple slow speed blending is not effective.

In the present invention, the infrared absorption spectrum of the charge control agent was measured using FT-IR1600 type manufactured by Perkin Elmer. The activated charge control agent is extracted by KBr method or carbon tetrachloride from the toner and measured by the liquid cell method, and a baseline connecting 1700 cm ^-1 and 1210 cm ^-1 is created and its base 1500 ± 10cm ^-1 , 1575 ± 10cm from line
^The transmittance ratio was determined from the peak heights at ⁻¹ and 1340 ± 10 cm ⁻¹ .

In the present invention, the primary average particle diameter of the charge control agent is measured as follows. Transmission electron microscope (Hitachi, Ltd. H-
700H) was used to take a sample of collodion film copper mesh, and the image was taken at 10,000 times at an applied voltage of 100 KV and the baking magnification was 3
The final magnification is 30,000 times. Thus, the maximum length of each particle is measured, and the average is defined as the average particle size.

The secondary particle size is measured by a centrifugal sedimentation type automatic particle size distribution analyzer CA.
It was performed using PA-700. 5 mg of the sample was mixed with 109 p1 drops of Emulgen and dispersed, added to 10 ml of an aqueous sodium hexametaphosphate solution in a beaker, dispersed for 5 minutes in an ultrasonic generator, and measured at 23 ± 2 ° C.

The charge control agent of the present invention, when mixing the raw materials with a blender or the like, while suppressing the temperature increase at 10 ℃ ~ 60 ℃, for example, it is also effective to high speed of 1000 rpm or more, the present invention Fine particles of the charge control agent of (1) to the impact portion formed of a rotating piece and a fixed piece and having a shortest gap of 0.5 to 10 mm, or the impact portion formed of at least two kinds of rotating pieces and having a shortest gap of 0.5 to 10 mm. It is also effective to crush the fine powder and activate the surface by mechanical impact at the impact part.

For example, as an example of a crushing device for carrying out the present method, a pin mill type having a recycle function and a large number of rotating pins, or an impact between a rotating blade or hammer (rotating piece) and a liner (fixing piece) A crusher (see Fig. 1-1) that gives a recycle function is effective.

The peripheral speed of the tip of the rotary piece in the device is preferably 20 to 300 m / sec, and the residence time of the impact portion is preferably 0.02 to 12 sec. In the case of the pin mill type, it is necessary to increase the powder concentration.

In the apparatus of the type shown in FIG. 1-1, the fine powder to be processed by centrifugal force is collected in the vicinity of the liner, so the latitude of the fine powder concentration is wide. Minimum clearance between pin mill or blade or hammer and liner is 0.5-10m
m is preferable, and good results are obtained when the thickness is adjusted to 1 mm to 3 mm.

Explaining in more detail with reference to FIG. 1-1, the fine powder is introduced from the inlet 13, passes through the inlet chamber 9, and the impact portion between the blade 4 and the liner 7 rotating along the rotating dispersion blade 3. 8 through the outlet chamber 10 and the return passage 11 to circulate the circuit again. After the crushing process is completed, the product is taken out from the product take-out port 12.

Here, the fine powder is subjected to an impact between the blade 4 and the liner 7 at the impact portion 8 and is subjected to a crushing process. Here, if necessary, it is preferable to flow cooling water into the jacket 15 to adjust the ambient temperature. 1-2
In the figure, a gap a between the blade 4 and the liner 7 is the shortest gap, and a space corresponding to the width b of the blade 4 is an impact portion.

If the fine powder to be treated is easily crushed, it may be crushed continuously without being recycled.

Next, other materials required for forming the present invention will be described.

As the binder resin used in the present invention, all resins generally used as binder resins for toner can be used.

For example, polystyrene, poly-p-chlorostyrene,
A homopolymer of styrene such as polyvinyltoluene or a substitute thereof; a styrene-p-chlorostyrene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, a styrene-acrylic acid ester copolymer, Styrene-methacrylic acid ester copolymer, styrene-α-chloromethacrylic acid copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone Styrene-based copolymers such as copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chloride, phenol resins, natural modified phenol resins, natural resin modified maleins Acid resin, acrylic resin , Methacrylic resins, polyvinyl acetate, silicone resins, polyester resins, polyurethane, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resin, chroman indene resin, and petroleum resins.

Further, a crosslinked styrene copolymer is also a preferable binder resin.

Examples of the comonomer for the styrene monomer of the styrene-based copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid. Acid, monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide and the like; or maleic acid, butyl maleate, malein. Dicarboxylic acids having double bonds such as methyl acidate, dimethyl maleate and the like, and substituted compounds thereof; for example, vinyl chloride, vinyl acetate,
Vinyl esters such as vinyl benzoate; ethylenic olefins such as ethylene, propylene, butylene; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone; vinyl methyl ether, vinyl ethyl ether; Vinyl monomers such as vinyl isobutyl ether and the like; alone or two or more vinyl monomers are used.

Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, or the like; for example, ethylene glycol diacrylate, ethylene glycol diacrylate, or the like. Double bonds such as methacrylate, 1,3-butanediol dimethacrylate
Carboxylic acid esters; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone; and compounds having three or more vinyl groups are used alone or as a mixture.

When a pressure fixing method is used, a binder resin for a pressure fixing toner can be used. For example, polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer can be used. Coalescent, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin and the like.

In the toner of the present invention, conventionally known dyes and pigments can be used as the colorant, for example, phthalocyanine blue, pekotsk blue, permanent red,
It can be widely used in lakes, rhodamine lakes, Hansa yellow, permanent yellow, benzine yellow and the like.

As its content, 0.5 to 20 parts by weight with respect to 100 parts by weight of the binder resin, and in order to improve the transparency of the OHP film, it is preferably 12 parts by weight or less, more preferably 0.5 to
9 parts by weight is good.

Examples of the carrier that can be used in the present invention include magnetic powders such as iron powders, ferrite powders and nickel powders, and those whose surfaces are treated with a resin or the like. It is preferable to use 10 to 1000 parts by weight of the carrier (preferably 30 to 500 parts by weight) with respect to 10 parts by weight of the toner.
The particle size of the carrier is 4-150 μm (preferably 10-1).
00 μm) is preferable.

Further, when the toner of the present invention is used as a magnetic toner, it contains a magnetic material which may also serve as a colorant. Examples of the magnetic material contained in the magnetic toner of the present invention include iron oxides such as magnetite, γ-iron oxide, ferrite, and iron-excess type ferrite; metals such as iron, cobalt, nickel, or these metals and aluminum, cobalt;
Examples include alloys with metals such as copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These ferromagnetic substances preferably have an average particle diameter of 0.1 to 1 μm, preferably about 0.1 to 0.5 μm, and the amount contained in the magnetic toner is 40 to 1 part by weight per 100 parts by weight of the resin component.
50 parts by weight, preferably 50 to 120 per 100 parts by weight of the resin component
Parts by weight.

In order to obtain good development characteristics, magnetic toner
The residual magnetization σ _r is 0.5 to 6 emu / g, preferably 1 to 5 emu / g, the saturation magnetization σ _s is 10 to 40 emu / g, and the coercive force H _c is 2
It is preferable that the magnetic properties of 0 to 100 est (e) are satisfied (the measured magnetic field is 1 Ke in all cases).

The toner of the present invention may be mixed with additives as necessary. As an additive, for example, a lubricant such as zinc stearate, or a polishing agent such as cerium oxide or silicon carbide or a fluidity imparting agent such as aluminum oxide;
Anti-caking agent, or for example carbon black,
There is a conductivity imparting agent such as tin oxide.

Further, a fluorine-containing polymer fine powder such as a polyvinylidene fluoride fine powder is also a preferable additive from the viewpoint of fluidity, abrasiveness, charge stability and the like.

In addition, wax-like substances such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, microcrystalline wax, carnauba wax, sasol wax, and paraffin wax are used for the purpose of improving the releasability at the time of hot roll fixing.
It is also one of the preferable modes of the present invention to add about 5 wt% to the magnetic toner.

In producing the toner according to the present invention, the above-mentioned toner constituent materials are sufficiently mixed by a ball mill or other mixer, then kneaded well using a hot roll kneader or an extruder heat kneader, and cooled and solidified. , Mechanical pulverization, a method of obtaining a toner by classification, is preferred,
Another method is to obtain a toner by dispersing constituent materials in a binder resin solution and then spray-drying; or an emulsified suspension prepared by mixing a predetermined material with a monomer that constitutes the binder resin. And a polymerization method for obtaining a toner by polymerization, or a so-called microcapsule toner comprising a core material and a shell material, and a method in which a predetermined material is contained in both the core material and the shell material; Can be applied. Further, if necessary, predetermined additives can be sufficiently mixed with a mixer such as a Henschel mixer to produce the toner according to the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used as a toner for visualizing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, etc. by a conventionally known means.

 Hereinafter, the present invention will be described specifically with reference to examples.

〔Example〕

Example 1 A twin-screw kneading extruder set to 120 ° C. after sufficiently mixing the above materials by applying a strong shearing force at a high speed of 2200 rpm with a blender in which the jacket was water-cooled with a chiller so that the internal temperature was always below 40 ° C. Was kneaded while cooling so that the outlet resin temperature became 150 ° C. or less.

The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by using a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier to classify. The powder was purified.

Further, the obtained finely divided powder is subjected to strict classification of ultrafine powder and coarse powder at the same time with a multi-division classifier utilizing the Coanda effect (Nippon Mining Co., Ltd. Elbow Jet classifier) to obtain a black fine powder having a volume average particle size of 11.5 μm. A body (non-magnetic toner) was obtained.

In the infrared absorption spectrum of the charge control agent (A) in the obtained toner, as shown in FIG. 2, T _(A) / T _(B) was about 0.31, and T _(C) / T _(B) Was about 0.75.

To 100 parts by weight of the obtained black fine powder non-magnetic toner, 0.3 parts by weight of positively charged hydrophobic dry silica (BET specific surface area 150 m ² / g) was added, and mixed with a Henschel mixer to make positive addition of silica. A non-magnetic toner having a charging property was used. The non-magnetic toner
A two-component non-magnetic developer was prepared by mixing 10 parts by weight and 100 parts by weight of fluorine / acrylic resin-coated ferrite carrier (average particle size: about 60 μm).

The obtained developer was used in a commercially available electrophotographic copying machine NP-5540.
10,0 using a color developer (manufactured by Canon Inc.)
A 00 copy test was conducted. From the initial stage, a clear image with an image density of 1.40 was obtained, and a good image with an image density of 1.43 was obtained even after 10,000 sheets were run.

Even under low humidity conditions of 20 ° C and 7.5% RH, the image density was stable at 1.43, and clear images were obtained without fog. Furthermore, the image density is stable at 1.36 under high temperature and high humidity conditions of 30 ° C and 85% RH, and the charging ability is 13 to 13.5 μc /
There was little change with g.

The charging ability was measured by the blow-off method after mixing 10 parts of the non-magnetic toner with 90 parts of iron powder (75 to 50 μm) in each environment.

Example 2 In the same manner as in Example 1, a blue fine powder (blue toner) having a volume average particle diameter of 10 μm was obtained, and 100 parts by weight of the blue toner and 0.5 parts by weight of positively charged hydrophobic silica were mixed with a Henschel mixer. Using the obtained silica externally added blue toner, a two-component developer was prepared in the same manner as in Example 1, and a copying test was performed using a color developing processor of a commercially available electrophotographic copying machine NP2015. Image density is stable at 1.39,
Even when toner supply was repeated, a stable image was always obtained. Further, no defects such as fogging and image blurring due to unstable charge amount were observed.

Example 3 The charge control agent (C) was prepared using the apparatus shown in FIG.
It was obtained by performing crushing and surface activation treatment for 1 minute at a blade peripheral speed of 80 m / sec for 3 minutes. 1300rp with the above materials in a blender
After mixing at m, kneading was performed with a twin-screw kneading extruder set at 120 ° C. while cooling so that the outlet resin temperature was 150 ° C. or less.

The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by using a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier to classify. The powder was purified.

Further, the obtained finely divided powder is subjected to strict classification of ultrafine powder and coarse powder at the same time with a multi-division classifier utilizing the Coanda effect (Nippon Mining Co., Ltd. Elbow Jet classifier) to obtain a black fine powder having a volume average particle size of 11.5 μm. A body (magnetic toner) was obtained.

0.5 parts by weight of positively charged hydrophobic silica (BET specific surface area 150 m ² / g) was added to 100 parts by weight of the obtained black fine powder magnetic toner, and the mixture was mixed with a Henschel mixer to obtain positively charged silica. Magnetic toner.

The obtained magnetic toner was used in a commercial electrophotographic copying machine NP-2015.
(Manufactured by Canon Inc.), and a 10,000-sheet copy test was performed.
The image density was stable at 1.40, and a stable and clear image was always obtained.

Comparative Example 1 A test was conducted in the same manner as in Example 1 except that the following charge control agent (D) was used.

Charge control agent (D) In the infrared absorption spectrum of the charge control agent (D) in the obtained toner, as shown in FIG. 2, T _(A) / T _(B) was about 0.56, and T _(C) / T _(B) Was about 0.57.

The image density was as low as 1.21 at the beginning, and reached 1.38 after about 1,000 sheets, but dropped to 1.25 again. In addition, the image was a dirty image with conspicuous fog.

Comparative Example 2 The same raw materials as in Example 2 were used, except that they were simply mixed with a blender at 550 rpm and kneaded with a kneader set to 200 ° C. The absorption spectrum is T _(A) / T _(B) is 0.64, T _(C) / T
_(B) was 0.48. When an image was formed with the toner obtained in the same manner, the image density was low at 1.23 in the case of a dusty image.

[Brief description of the drawings]

FIG. 1-1 is a view schematically showing an example of a preferable apparatus for crushing fine powder, and FIG. 1-2 is a partially enlarged view of the apparatus shown in FIG. 1-1. FIG. 2 is an infrared absorption spectrum of the charge control agent in the toners of Example 1 and Comparative Example 1. 1 ... Rotary axis, 2 ... Rotor 3 ... Dispersion blade, 4 ... Rotating piece (blade) 5 ... Partitioning disk, 6 ... Casing 7 ... Liner, 8 ... Impact section 9 ... Inlet chamber , 10 …… Exit chamber 11 …… Return path, 12 …… Product extraction valve 13 …… Raw material input valve, 15 …… Jacket

Claims (3)

(57) [Claims] At least a binder resin, a colorant and a positive charge
In a positively chargeable toner containing a control agent, the positively chargeable control agent has the formula[Where R₁, R_TwoAnd R_ThreeAre the same or different
Is a group which may be a hydrogen atom, a halogen atom, an alkyl
A group or an alkoxy group, A Represents an anion. A compound having a basic skeleton represented by the formula: wherein the compound in the toner has an infrared absorption spectrum
1500 ± 10 cm^-1Absorption peak T of_(A)And 1575 ± 10 cm^-1Sucking
Peak T_(B)Ratio with (T_(A)/ T_(B)) Is 0.1 to 0.5,
And 1340 ± 10 cm^-1Absorption peak T of_(C)And 1575 ± 10 cm^-1Sucking
Peak T_(B)Ratio with (T_(C)/ T_(B)) Is 1.0 to 0.6
And a positively chargeable toner. 2. The method according to claim 1, wherein the anion is a halogen ion, a sulfate ion,
The positively chargeable toner according to claim 1, which is a nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, organic borate ion or carboxylate ion. 3. The positively chargeable toner according to claim 1, wherein finely charged positively chargeable silica powder is externally added to the positively chargeable toner.