JP2748164B2 - Negatively chargeable toner for developing electrostatic latent images - Google Patents

Description

The present invention relates to a negatively chargeable toner for developing an electrostatic latent image for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior Art] Various conventional electrophotographic methods are described in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-24748.

Developing methods applied to the electrophotographic method and the like are roughly classified into a dry developing method and a wet developing method. The former is further classified into a method using a two-component developer and a method using a one-component developer.

Conventional toners applied to these dry development methods include:
Fine powders in which dyes and pigments are dispersed in natural or synthetic resins are used. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and finely pulverized to about 1 to 30 μm are used as toner. As the magnetic toner, a toner containing magnetic particles such as magnetite is used. In the case of using a two-component developer, the toner is usually used by being mixed with carrier particles such as glass beads and iron powder.

Any toner must have a positive or negative charge, depending on the polarity of the electrostatic latent image to be developed.

In order to cause the toner to retain electric charge, it is possible to use the frictional charging property of the resin, which is a component of the toner.However, since the charging property of the toner is small, an image obtained by development is easily fogged and unclear. Becomes Therefore, in order to further impart triboelectricity to the toner, a substance called a charge control agent is generally added.

Today, the charge control agents known in the art include, as negatively triboelectric ones, metal complex salts of monoazo dyes, metal complex salts of salicylic acid, metal complex salts of naphthoic acid, metal complex salts of dicarboxylic acid, copper phthalocyanine pigments and so on.

[Problems to be Solved by the Invention] Many of the charge control agents described above have a sufficiently high charge providing ability, but are colored and cannot be used for color toner. In addition, since certain control agents easily contaminate a toner carrier such as a sleeve or a carrier, the toner using the toner decreases the triboelectric charge amount with an increase in the number of copies and causes a decrease in image density. Easy to do. Further, since the amount of triboelectric charge of a certain control agent greatly varies depending on the binder resin used, there are restrictions on the binder resin or other materials that can be used. Further, although excellent in triboelectricity, many of them are poor in controllability and are likely to be excessive.

At present, there is a strong demand for the development of charge control agents that satisfy all of these.

The object of the present invention is to use a charge control agent which solves the above problems. It is to provide an excellent toner.

That is, the amount of triboelectric charge between toner particles, between toner and carrier, or between toner and toner carrier such as sleeve in the case of one-component development is stable without environmental temperature and humidity changes, An object of the present invention is to provide a negatively chargeable toner for developing an electrostatic latent image capable of reproducing a stable image which is not affected by a change.

It is a further object of the present invention to provide a negatively chargeable toner for developing an electrostatic latent image, in which the toner is uniformly dispersed or compatible in the binder resin and the toner particles are uniformly charged to give a clear image without fog. is there.

[Means and Actions for Solving the Problems] That is, the present invention provides a compound represented by the general formula (I): (Wherein, X represents a halogen or an alkoxy group, Y represents hydrogen, a hydroxy group, an amino group, an alkyl group, a halogen,
R ₁ and R ₂ each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group, and may form a ring. n is an integer indicating a degree of polymerization of 2 or more. The present invention relates to a negatively chargeable toner for developing an electrostatic latent image, comprising a salicylic acid resin represented by the following formula:

JP-A-63-33755 discloses a two-component toner containing salicylic acid and a metal salt of a salicylic acid compound.

However, salicylic acid itself has sublimation properties and is not sufficiently negatively chargeable, so its use is very limited. On the other hand, some metal complexes of salicylic acid compounds have excellent triboelectric charging properties and are generally widely used. However, the triboelectric charging property of the metal complex does not depend only on the ligand, and the charge amount often changes to the plus or minus sign depending on the central metal. Therefore, it is impossible to predict the triboelectric charging property of the ligand from the result of the metal complex.

The inventors of the present invention have studied salicylic acid derivatives based on an original idea, and have found that the amount of negative triboelectric charge can be increased by introducing a substituent into salicylic acid. However, these salicylic acid derivatives also have sublimability like salicylic acid, and are not suitable for producing toners at high temperatures.

Thus, when the salicylic acid compound was increased in amount as shown in the formula (I), it was found that the toner had no sublimation property, and the toner had a higher negative triboelectric charge than the corresponding monomer and was substantially colorless. It was found to be pale enough to be considered.

Further, since the dispersibility in the binder resin was improved as compared with the conventional metal compound, the frictional charging between the toner particles became uniform, the generation of the oppositely charged particles was suppressed, and no fogging occurred. Further, contamination of the toner carrier such as the sleeve and the carrier could be reduced.

In addition, the dependence of the image on the environment is reduced as compared with conventional metal compounds, and an image having a sufficient density can be obtained under high-temperature and high-humidity conditions or constant-temperature and low-humidity conditions.

As described above, it has been found that the toner containing the salicylic acid resin of the present invention has excellent properties as compared with the toner containing the conventional charge control agent, and thus the present invention is met.

One of the monomers used for synthesizing the salicylic acid resin of the present invention includes a salicylic acid compound represented by the formula (II).

Y represents hydrogen, a hydroxy group, an amino group, an alkyl group, a halogen, or an alkoxy group. The alkyl group preferably has 24 or less carbon atoms for synthesis. When the number of carbon atoms exceeds 24, the degree of polymerization of the product decreases and the yield also decreases.

The alkoxy group preferably has 6 or less carbon atoms in consideration of ease of synthesis.

On the other hand, it is the xylene compound represented by the following formula (III) that acts on the salicylic acid compound represented by the above formula (II) to form the salicylic acid resin of the present invention.

X represents a halogen or an alkoxy group.

Considering ease of synthesis as halogen, chlorine,
Bromine and iodine are preferred. The alkoxy group preferably has 6 or less carbon atoms in consideration of ease of synthesis. When the number of carbon atoms exceeds 6, by-products are apt to be generated during the synthesis, which impairs the charging performance of the obtained resin. R ₁ and R ₂ each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group, and may form a ring.

Hereinafter, specific examples of the salicylic acid compound and the xylene compound that can be used in the present invention are shown, but these are typical examples in consideration of easiness of the synthesis method and the like, and do not limit the compounds of the present invention at all.

Examples of salicylic acid compounds Xylene compound example The salicylic acid resin of the present invention can be synthesized from a salicylic acid compound represented by the formula (II) and a xylene compound represented by the formula (III) using a known method.

When αα ′ dihalogenoxyxylene is used as the xylene compound of the formula (III), the target salicylic acid resin can be obtained by allowing zinc halide or the like to act on xylene in an equimolar amount to salicylic acid.

When αα ′ dialkoxyxylene is used as the xylene compound of the formula (III), an acid such as hydrochloric acid or sulfuric acid or a Friedel-craft catalyst such as zinc chloride or ferric chloride is allowed to act on salicylic acid and the xylene compound. Thereby, the desired salicylic acid resin can be obtained.

Hereinafter, specific examples of the salicylic acid resin of the present invention are shown, but these are representative examples in consideration of easiness of the synthesis method and the like, and do not limit the compound of the present invention at all.

Compound example As a method for incorporating the salicylic acid resin of the present invention into the toner, there are a method of adding the resin inside the toner and a method of externally adding the same. The amounts of these compounds used are determined by the type of the binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and are not specifically limited. However, it is preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin. When adding externally, use resin 100
The amount is preferably 0.01 to 10 parts by weight with respect to part by weight, and particularly preferably, the toner is fixed to the surface of the toner particles by a mechanochemical method or the like.

Further, the compound used in the present invention can be used in combination with a conventionally known charge control agent.

Examples of the coloring agent used in the present invention include carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6G, lake,
Calco oil blue, chrome yellow, quinacridone,
Conventionally known dyes and pigments such as benzidine yellow, rose bengal, triarylmethane dyes, monoazo and disazo dyes can be used alone or in combination.

The resin used in the present invention includes, for example, styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyl toluene, and a homopolymer of a substituted product thereof;
p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer,
Styrene-vinyl ethyl ether copolymer, styrene-
Styrene-based copolymers such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenolic resin, naturally modified phenolic resin, natural Resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, cumarone indene resin, petroleum resin Etc. can be used.

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

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, and methacrylic. Acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, monocarboxylic acid having a double bond such as acrylamide or the like; for example,
Dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; Olefins such as ethylene, propylene and butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; Monomers may be used alone or in combination of two or more.

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 having two or more compounds; 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-isobutylene copolymer, linear saturated polyester, paraffin and the like.

The toner of the present invention contains a magnetic material and can be used as a magnetic toner. 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-rich ferrite; metals such as iron, cobalt, and nickel; or aluminum and 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 to 100 parts by weight, preferably 100 to 100 parts by weight of the resin component.
Parts by weight.

Further, when the toner of the present invention is used as a two-component developer, it is used by mixing with a carrier powder. As the carrier that can be used in the present invention, known carriers can be used, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads, and the like, and those obtained by treating the surface with a resin or the like. And so on. Further, as the resin for coating the carrier surface, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate copolymer, methacrylate copolymer, silicone resin, fluorine-containing resin,
A polyamide resin, an ionomer resin, a polyphenylene sulfide resin, or the like, or a mixture thereof can be used.

The toner of the present invention may optionally contain additives. Examples of the additive include a lubricant such as zinc stearate; an abrasive such as cerium oxide and silicon carbide; a fluidity imparting agent such as silica fine powder and aluminum oxide; a caking inhibitor; or a carbon black and tin oxide. There is a conductivity imparting agent.

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.

Further, in order to improve the releasability at the time of hot roll fixing, a wax-like substance such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sasol wax, paraffin wax, etc.
Addition of about 5% by weight to the toner is also a preferred embodiment of the present invention.

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 heat kneader of a hot roll kneader or an extruder, and cooled and solidified. A method of obtaining a toner by mechanical pulverization and classification is preferable. Alternatively, a method of dispersing a constituent material in a binder resin solution and then spray-drying to obtain the toner; or a method of forming the binder resin A polymerized toner production method in which a predetermined material is mixed with a monomer to form an emulsified suspension and then polymerized to obtain a toner; or in a so-called microcapsule toner comprising a core material and a shell material, a core material or a shell material. ,
Alternatively, a method of including a predetermined material in both of them can be applied. Further, if necessary, the desired additive is sufficiently mixed with a mixer such as a Henschel mixer to produce the toner according to the present invention.

The toner of the present invention can be used for development for visualizing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, by a conventionally known means.

The salicylic acid resin having a substituent of the present invention is colorless or light-colored without practical problems, and has a sufficient negative triboelectric charging property. In addition, the dispersibility in the binder resin was improved as compared with conventionally known metal compounds. Further, the sublimation property of salicylic acid or a salicylic acid derivative could be completely solved.

Therefore, the toner containing the salicylic acid resin having a substituent of the present invention as a charge control agent can always provide a good and stable image because contamination of a toner carrier such as a sleeve or a carrier is small. Further, it can be used as a charge control agent for a color toner, and can provide a color image. Since it has no sublimation property and is excellent in thermal stability, it is possible to stably produce and supply the toner without any special measures in the toner manufacturing process and in selecting other raw materials.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. All parts in the following formulations are parts by weight.

Example 1 After the above materials were mixed well in a blender, they were kneaded in a twin-screw kneading extruder set at 130 ° C. The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier.

Further, the obtained fine powder is strictly classified and removed simultaneously by a multi-division classifier utilizing a Coanda effect (an elbow jet classifier manufactured by Nittetsu Mining Co., Ltd.), and the volume average particle diameter is 11.2μ.
m was obtained.

Silica fine powder (BET specific surface area: 200 m ² / g) which was hydrophobized with dimethyldichlorosilane to 100 parts of the obtained fine powder
0.5 part was added and mixed with a Henschel mixer to obtain a negatively chargeable toner.

Next, 10 parts of the obtained toner were mixed with 100 parts of an acrylic-coated ferrite carrier having an average particle size of 65 μm to prepare a developer.

When this developer was applied to a commercially available copying machine (trade name: NP-6650, manufactured by Canon Inc.) and subjected to a copying test at 23 ° C./60% environment, an image with good image quality of 1.30 was obtained. Was done. Using the above-mentioned developer, continuous printing was performed for 4,000 sheets, and the durability performance was examined. As a result, a good image comparable to the initial image was obtained.

Next, a copy test was performed under environmental conditions of 15 ° C./10% and 35 ° C./83%, and similarly good results were obtained.

Example 2 After the above materials were mixed well in a blender, they were kneaded with a twin screw extruder set at 130 ° C. The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier.

Furthermore, the obtained fine powder is strictly classified and removed simultaneously by a multi-division classifier utilizing the Coanda effect (an elbow jet classifier manufactured by Nippon Steel Mining Co., Ltd.), and the volume average particle diameter is 11.6μ.
m was obtained.

Silica fine powder (BET specific surface area: 300 m ² /
g) 0.4 part was added and mixed with a Henschel mixer to obtain a negatively-chargeable magnetic toner.

When this toner was applied to a commercial copying machine (trade name: NP-6650, manufactured by Canon Inc.) and subjected to a copying test at 23 ° C./60% environmental conditions, the image density was 1.34, and there was no fog or dust. A clear image was obtained. Furthermore, when 30,000 copies were continuously copied, the durability performance was examined. As a result, an image having an image density of 1.33 and a good image comparable to the initial image were obtained. Also, when the triboelectric charge amount of the toner on the developing sleeve was measured,
Initially -10.3 μc / g, after copying 30,000 sheets, -10.0 μc / g
At μc / g, little sleeve contamination was observed.

Next, when a copy test was conducted under an environmental condition of 15 ° C./10%, an image of high density and good image quality was obtained. 3
The results were similarly good in the continuous copying test of 10,000 copies.

When the same copy test and continuous copy test were performed under the environmental conditions of 35 ° C./85%, good results were obtained. Further, after the toner was allowed to stand for one month under these environmental conditions, the same copying test and continuous copying test were performed. The results were satisfactory without any problem.

Example 3 A fine powder having a volume average particle diameter of 11.1 μm was obtained in the same manner as in Example 1, except that 2 parts of Compound Example (3) in Example 2 was changed to 3 parts of Compound Example (2). To 100 parts of this fine powder,
Silica fine powder (BE
0.4 parts by mass (T specific surface area: 200 m ^{2 /} g) were added and mixed with a Henschel mixer to obtain a negatively-chargeable magnetic toner.

When this toner was applied to a commercially available copying machine (trade name: NP-6650, manufactured by Canon Inc.) and subjected to a copying test under environmental conditions of 23 ° C./60%, the image density was as high as 1.32, and the fog was reduced. A clear image without roughness was obtained. Subsequently, when 20,000 sheets were continuously copied, and the durability performance was examined, a good image comparable to the initial image was obtained. When the triboelectric charge of the toner on the developing sleeve was measured, it was -9.3 µc / g at the initial stage, and -9.1 µc / g after copying 20,000 sheets, and almost no sleeve contamination was observed.

Next, when a copy test was conducted under an environmental condition of 15 ° C./10%, an image of high density and good image quality was obtained. 2
The results were similarly good in the continuous copying test of 10,000 copies.

When the same copy test and continuous copy test were performed under the environmental conditions of 35 ° C./85%, good results were obtained. Further, after the toner was allowed to stand for one month under these environmental conditions, the same copying test and continuous copying test were carried out. The results were satisfactory without any problem.

Example 4 After the above materials were mixed well in a blender, they were kneaded with a biaxial kneading extruder set at 150 ° C. The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier.

Furthermore, the obtained fine powder was strictly classified and removed simultaneously by a multi-division classifier utilizing a Coanda effect (an elbow jet classifier manufactured by Nittetsu Mining Co., Ltd.), and the volume average particle diameter was 8.5μ.
m was obtained.

Silica fine powder (BET specific surface area: 300 m ² /
g) 0.6 part was added and mixed with a Henschel mixer to obtain a negatively chargeable toner.

Next, 6 parts of the obtained toner was mixed with 100 parts of an acrylic-coated ferrite carrier having an average particle diameter of 65 μm to prepare a developer.

This developer was used in a commercially available color electrophotographic copying machine CLC-1.
(Manufactured by Canon Inc.).

As a result, under an environmental condition of 23 ° C./60%, a bright black image with an image density of 1.42 was obtained from the beginning, and no deterioration was observed after 10,000 copies.

Next, when a copy test was performed under an environmental condition of 15 ° C./10%, an image having a high density of 1.39 was obtained from the beginning. In addition, 32
A good image with a density of 1.43 was obtained even under the environmental conditions of ° C / 85%.

Example 5 A fine powder having a volume average particle size of 8.6 μm was obtained in the same manner as in Example 4 except that 5 parts of carbon black in Example 4 was changed to 4 parts of a copper phthalocyanine pigment (CI Pigment Blue 15). Thus, a negatively chargeable toner was obtained.

Next, the same carrier as in Example 4 was mixed at the same ratio to obtain a developer.

This developer was subjected to a copy test in the same manner as in Example 4. As a result, under the environmental conditions of 23 ° C / 60%,
A good blue image without fog having a density of 1.39 was obtained. 1
No deterioration in image quality was observed even after copying 10,000 sheets.

A copy test was performed under environmental conditions of 35 ° C./85% and 15 ° C./10%, and good results were obtained as in the case of 23 ° C./60%.

Example 6 A fine powder having a volume average particle size of 8.8 μm was obtained in the same manner as in Example 4 except that carbon black in Example 4 was replaced with 4 parts of a quinacridone pigment (CI Pigment Red 122), and silica was further mixed. Thus, a negatively chargeable toner was obtained.

Next, the same carrier as in Example 4 was mixed at the same ratio to obtain a developer.

This developer was subjected to a copy test in the same manner as in Example 4. As a result, under the environmental conditions of 23 ° C / 60%,
A good magenta image with a density of 1.32 without fog was obtained. No deterioration in image quality was observed even after copying 10,000 sheets.

A copy test was performed under environmental conditions of 35 ° C./85% and 15 ° C./10%, and good results were obtained as in the case of 23 ° C./60%.

Example 7 A fine powder having a volume average particle diameter of 8.9 μm was obtained in the same manner as in Example 4 except that 5 parts of carbon black in Example 4 was changed to 5 parts of a 2,9-dimethylquinacridone-based pigment, and further mixed with silica. A negatively chargeable toner was obtained.

Next, the same carrier as in Example 4 was mixed at the same ratio to obtain a developer.

This developer was subjected to a copy test in the same manner as in Example 3. As a result, under the environmental conditions of 23 ° C / 60%,
A good yellow image without fog having a density of 1.39 was obtained. 1
No deterioration in image quality was observed even after copying 10,000 sheets.

A copy test was performed under environmental conditions of 35 ° C./85% and 15 ° C./10%, and good results were obtained as in the case of 23 ° C./60%.

Example 8 When a full-color image was obtained using the black, cyan, magenta, and yellow developers used in Examples 4 to 7, a vivid full-color image excellent in color mixing and gradation was obtained.

Example 9 After the above materials were mixed well in a blender, they were kneaded with a biaxial kneading extruder set at 150 ° C. The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized by a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier.

Further, the obtained classified powder is strictly classified and removed simultaneously by a multi-division classifier using a Coanda effect (an elbow jet classifier manufactured by Nittetsu Mining Co., Ltd.), and the volume average particle size is 9.6 μm.
m was obtained.

Silica fine powder (BET specific surface area: 300 m ² / g) hydrophobized with 100 parts of the obtained fine powder with hexamethyldisilazane
0.6 part was added and mixed with a Henschel mixer to obtain a negatively chargeable toner.

Next, 6 parts of the obtained toner was mixed with 100 parts of an acrylic-coated ferrite carrier having an average particle diameter of 65 μm to prepare a developer.

This developer was used in a commercially available color electrophotographic copying machine CLC-1.
(Manufactured by Canon Inc.).

As a result, under an environmental condition of 23 ° C./60%, a bright black image having an image density of 1.41 was obtained from the beginning, and no deterioration was observed after 10,000 copies.

Next, when a copy test was performed under an environmental condition of 15 ° C./10%, an image with a high density of 1.32 was obtained from the beginning. In addition, 32
A good image with a density of 1.43 was obtained even under the environmental conditions of ° C / 85%.

[Effects of the Invention] As described above, a negatively chargeable toner containing the salicylic acid resin of the present invention as a charge control agent has a uniform triboelectric charge amount between toner particles and gives a good image without fog.
Further, since contamination of the toner carrier such as the sleeve and the carrier by the charge control agent is reduced, an image having a sufficient density can be obtained even after a large amount of copying, and the density is stable. Furthermore, since the image density is less dependent on temperature and humidity and does not easily change over time, the quality stability during storage is excellent.

Further, since the color tone disturbance due to the charge control agent is small, it can be used for a color toner.

Claims (1)

(57) [Claims] 1. The compound of the general formula (I) (Wherein, X represents a halogen or an alkoxy group, Y represents hydrogen, a hydroxy group, an amino group, an alkyl group, a halogen,
R ₁ and R ₂ each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group, and may form a ring. n is an integer indicating a degree of polymerization of 2 or more. A negatively chargeable toner for developing an electrostatic latent image, comprising a salicylic acid resin represented by the following formula: