JP2001013734A - Negatively chargeable toner - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a negatively chargeable toner having a low minimum fixing temperature, excellent offset resistance, blocking resistance, and durability, as well as stable chargeability. A negatively chargeable toner comprising a binder resin, a wax, a negatively chargeable charge control agent and a positively chargeable charge control agent, wherein the acid value of the binder resin is 10 mgKOH / g or more, The melting point of the wax is 60 to 90 ° C., and the negatively chargeable charge control agent has the formula (I): (Wherein, R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a sulfonamide group, and the like; X ¹ and X ² are a hydrogen atom, 1
An alkyl group of 8 or an alkoxy group having 1 to 18 carbon atoms, A ⁺ represents a hydrogen ion or a sodium ion, and m and n each represent an integer of 1 to 3). Toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negatively chargeable toner used for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like.

[0002]

2. Description of the Related Art A toner containing a low-melting-point wax has been developed in order to prevent the offset phenomenon seen in a heat roll fixing system and to obtain a toner having excellent low-temperature fixability (Japanese Patent Application Laid-Open No. 8-220808). ), The viscosity of the melt-kneaded product is lowered, and it is difficult to obtain sufficient dispersibility of the charge control agent. If the charge control agent is not uniformly dispersed, the distribution of the charge amount of the toner is widened, and the one with a low charge amount causes the toner to scatter, while the one with a high charge amount is a carrier spent in a two-component developer. One cause is that the one-component developer fuses to the charging blade and deteriorates the durability of the developer. Therefore, there is a demand for development of a toner having excellent low-temperature fixability and having a charge control agent dispersed uniformly.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a negatively chargeable toner having a low minimum fixing temperature and excellent not only offset resistance, blocking resistance and durability but also stable chargeability. To provide.

[0004]

The present invention is directed to a negatively chargeable toner comprising a binder resin, wax, a negatively chargeable charge control agent and a positively chargeable charge control agent, The acid value is 10 mg KOH / g or more, the melting point of the wax is 60 to 90 ° C., and the negatively chargeable charge control agent has the formula (I):

[0005]

Embedded image

Wherein R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a sulfonamide group, a sulfonic acid group, a carboxyester group, a hydroxy group, Represents an alkoxy group, an acetylamino group, a benzoylamino group or a halogen atom represented by Formulas 1 to 18, wherein R ¹ and R ² may be the same or different; X ¹ and X ^{2 each} represent a hydrogen atom; Alkyl group having 18 to 18 carbon atoms, alkoxy group having 1 to 18 carbon atoms, 6 carbon atoms
Represents an aryl group, a nitro group or a halogen atom, and X ¹ and X ² may be the same or different;
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion or an ammonium ion, and m and n each represent an integer of 1 to 3).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The negatively chargeable toner of the present invention is represented by the following formula (I):

[0008]

Embedded image

(Wherein R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a sulfonamide group, a sulfonic acid group, a carboxyester group, a hydroxy group, Represents an alkoxy group, an acetylamino group, a benzoylamino group or a halogen atom represented by Formulas 1 to 18, wherein R ¹ and R ² may be the same or different; X ¹ and X ^{2 each} represent a hydrogen atom; Alkyl group having 18 to 18 carbon atoms, alkoxy group having 1 to 18 carbon atoms, 6 carbon atoms
Represents an aryl group, a nitro group or a halogen atom, and X ¹ and X ² may be the same or different;
A ⁺ represents a hydrogen ion, a sodium ion, a potassium ion or an ammonium ion, and m and n each represent an integer of 1 to 3). Usually, when a wax having a melting point of 60 to 90 ° C. (hereinafter referred to as a low melting point wax) and a negatively chargeable charge control agent are used in combination in the toner of the present invention, the dispersibility of the negatively chargeable charge control agent is reduced. However, since the metal complex salt compound represented by the formula (I) is very excellent in dispersibility, it can be uniformly dispersed in the toner. Furthermore, in the present invention, since a positively chargeable charge control agent is blended together with the metal complex salt compound, stable negative chargeability can be maintained.

In the present invention, among the metal complex compounds represented by the formula (I), R ¹ and R ² are halogen atoms, particularly chlorine atoms, X ¹ and X ² are aryl groups, especially phenyl groups, A ⁺ is preferably a hydrogen ion, a sodium ion or an ammonium ion, and a metal complex compound in which m and n are 1 is preferred.

The production method of the metal complex salt compound represented by the formula (I) is described in detail in Japanese Patent Application Laid-Open No. Sho 61-155644, and can be easily synthesized according to this method. However, as commercially available products, for example, "T-
77 "(manufactured by Hodogaya Chemical Co., Ltd.).

The content of the metal complex compound represented by the formula (I) is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the binder resin.

Examples of the positively chargeable charge control agent include nigrosine dyes such as "Nigrosine base EX", "Oil black BS", "Oil black SO", and "Bontron N".
-01 "," Bontron N-07 "," Bontron N-
09, "Bontron N-11" (all manufactured by Orient Chemical Industries) and the like; triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds, for example, "Bontron P-51", " Bontron P-52 "
(These products are manufactured by Orient Chemical Industries, Ltd.), "TP-415"
(Hodogaya Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (Hoechst Co., Ltd.) and the like; polyamine resins such as "AFP-B" (Orient Chemical Co., Ltd.) and the like; imidazole derivatives such as " PLZ-2001 "," PLZ-8001 "(or more,
Nigosine dyes are preferred from the viewpoints of dispersibility and stabilization of the charge amount of the toner.

The weight ratio of the positively chargeable charge control agent to the metal complex compound represented by the formula (I) is preferably from 1/99 to 50/50, more preferably from 5/95 to 30/70.

The acid value of the binder resin is 10 mgKOH / g or more, preferably 10 to 4 mg / g, from the viewpoint of durability and chargeability.
0 mgKOH / g, more preferably 10-30 mgKO
H / g.

The binder resin is preferably obtained by mixing a high melting point resin (A) and a low melting point resin (B) from the viewpoint of compatibility with the low melting point wax. Since the binder resin having a high softening point and the low melting point wax have significantly different melt viscosities, it is difficult to uniformly disperse the low melting point wax in the toner by melt kneading. However, when at least two types of resins having different softening points are contained, the resin having a low softening point serves as a link between the resin having a high softening point and the low melting point wax, and the low melting point wax is contained in the binder resin. Are more uniformly dispersed.

In the present invention, the physical properties and the compounding ratio of the resin (A) and the resin (B) are such that the excellent properties possessed by the respective resins are sufficiently exhibited, and the low-temperature fixing property, the offset resistance, the blocking resistance, and the like. In order to obtain a toner excellent in both durability, it is preferable to be defined as follows.

The softening point of the resin (A) is preferably 120 ° C. or higher from the viewpoint of offset resistance and durability, and 170 ° C. or lower from the viewpoint of the minimum fixing temperature, more preferably 13 ° C. or lower.
0-165 ° C.

The glass transition point of the resin (A) is preferably 58 ° C. or higher from the viewpoint of blocking resistance and 75 ° C. or lower from the viewpoint of the minimum fixing temperature, more preferably 58 to 70 ° C.
° C.

The chloroform-insoluble content of the resin (A) is preferably 5% by weight or more from the viewpoint of offset resistance and durability, and is preferably 50% by weight or less from the viewpoint of the minimum fixing temperature, more preferably 10 to 50% by weight. %. The chloroform-insoluble fraction in the present invention refers to the weight fraction of the resin component that does not dissolve in chloroform at 25 ° C.

In order to increase the compatibility between the resin (A) and the low melting point wax, the softening point of the resin (B) is preferably 90 ° C.
As described above, the temperature is less than 120 ° C, more preferably 90 to 110 ° C, the glass transition point is preferably 58 to 75 ° C, more preferably 58 to 70 ° C, and the chloroform-insoluble content is preferably less than 5% by weight. , More preferably 3% by weight
Hereinafter, it is particularly preferably 0% by weight.

The resin (A) / resin (B) (weight ratio) is preferably 10/90 to 90/10, more preferably 20/90 to 90/10.
/ 80-80 / 20, particularly preferably 40 / 60-70
/ 30.

Further, the binder resin used in the toner of the present invention may contain resin (C) in addition to resin (A) and resin (B). When the resin (C) is blended, it is possible to obtain a binder resin having a wide molecular weight distribution which cannot be obtained by merely mixing the two types of the resin (A) and the resin (B). Is also improved, and a toner having more excellent low-temperature fixability can be obtained. In consideration of these points, the softening point of the resin (C) is 80
To 110 ° C, preferably 90 to 110 ° C, a glass transition point of 45 ° C or higher and lower than 58 ° C, preferably 50 ° C or higher and lower than 58 ° C, and a chloroform-insoluble content of less than 5% by weight, preferably 3% by weight. % By weight or less, more preferably 0% by weight.

The resin (A) / resin [(B) + (C)] (weight ratio) is preferably 10/90 to 90/10, more preferably 40/60 to 80/20. ) /
The resin (C) (weight ratio) is preferably 10/90 to 90.
/ 10, more preferably 40/60 to 80/20, and the difference between the softening points of the resin (A) and the resin (B) or (C) is preferably 20 ° C. or more.

The resins (A) to (C) described above may be composed of a single resin or a mixture of two or more resins. Therefore, for example, the resin (A) may be composed of two or more kinds of resins, and the same applies to the resins (B) and (C).

As the binder resin, polyester,
Hybrid resins, styrene-acrylic resins, and the like are included. Among these, polyester and hybrid resins are preferable, and polyester is more preferable, from the viewpoints of fixability, durability, and colorant dispersibility.

The polyester used in the present invention can be produced, for example, using the compounds exemplified in JP-A-7-175260 and by referring to the method described therein.

As a raw material monomer of the polyester, a divalent or higher valent alcohol component and a carboxylic acid component such as a divalent or higher carboxylic acid, a carboxylic anhydride, a carboxylic acid ester and the like are used.

Preferred dihydric alcohol components include an alkylene (C2 or C3) oxide adduct of bisphenol A (average number of moles added: 1 to 10), ethylene glycol, propylene glycol, 1,6-hexanediol,
Bisphenol A, hydrogenated bisphenol A and the like.

Preferred trihydric or higher alcohol components are sorbitol, 1,4-sorbitan, pentaerythritol, glycerol, trimethylolpropane and the like.

Examples of the divalent carboxylic acid component include various dicarboxylic acids, succinic acid substituted with an alkyl or alkenyl group having 1 to 20 carbon atoms, anhydrides of these acids and alkyls (1 to 12 carbon atoms). ) Esters and the like;
Preferred are maleic acid, fumaric acid, terephthalic acid and succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms.

The preferred trivalent or higher carboxylic acid component is 1,1
2,4-benzenetricarboxylic acid (trimellitic acid), its acid anhydride, alkyl (1 to 12 carbon atoms) ester and the like.

When the raw material monomer of the polyester is polymerized, a commonly used esterification catalyst such as dibutyltin oxide may be appropriately used in order to accelerate the reaction.

In the present invention, as described in JP-A-8-171231, a hybrid resin is obtained by using a mixture of two polymerizable raw material monomers each having an independent reaction path as a raw material. Is obtained.

The two polymerization reactions proceed in independent reaction paths, and are preferably reactions that produce a condensation polymerization resin and an addition polymerization resin, respectively. As typical examples of the condensation polymerization resin, polyester, polyester
Polyamide, polyamide and the like are mentioned, and a typical example of the addition polymerization resin is a vinyl polymerization resin obtained by a radical polymerization reaction.

Among these, the polyester component can be obtained using the same divalent or higher valent alcohol component as described above and a carboxylic acid component such as a divalent or higher carboxylic acid, carboxylic anhydride, carboxylic acid ester or the like as a raw material monomer. .

The raw material monomers used to form the amide component in the polyester / polyamide or polyamide include various known polyamines, aminocarboxylic acids, amino alcohols, etc., preferably hexamethylenediamine and ε-caprolactam. It is.

The starting monomers used to form the vinyl polymer resin obtained by the addition polymerization reaction include styrene; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; ) Ethylenic monocarboxylic acids such as acrylic acid; alkyl of (meth) acrylic acid (C1-18)
Examples include esters of ethylenic monocarboxylic acids such as esters.

The hybrid resin is prepared by mixing a raw material monomer of a polycondensation resin, a raw material monomer of an addition polymerization resin, a polymerization initiator, and the like. It is preferable to obtain an addition polymerization type resin component having a group, then raise the reaction temperature to 190 to 270 ° C., and then form the condensation polymerization type resin component mainly by a condensation polymerization reaction. A resin in which the compatibility of two kinds of resins is improved can be efficiently obtained by using such a mixture of raw material monomers as raw materials and allowing two independent reactions to proceed.

The weight ratio of the polycondensation resin to the addition polymerization resin, that is, the weight ratio of the raw material monomer of the polycondensation resin to the raw material monomer of the addition polymerization resin is usually 50 from the viewpoint of the dispersibility of the addition polymerization resin. / 50 to 95/5, preferably 60/40 to 95/5.

The resins (A) to (A) described above
The physical properties of (C), that is, the softening point, the glass transition point, and the chloroform-insoluble content are determined by the type of the raw material monomer, polymerization initiator or catalyst, the amount thereof, the selection of the reaction conditions, etc., when producing each resin. It can be easily adjusted.

The binder resin used in the present invention is a resin in which powders of resins (A) and (B) or resins (A) to (C) or pellets are simply mixed. Alternatively, the resin may be uniformly mixed and dispersed by melt-kneading, and then pulverized or the like to form a powder or a pellet.

Examples of the low melting point wax used in the toner of the present invention include ester waxes such as carnauba wax, rice wax, candelilla wax and synthetic carnauba wax, and synthetic waxes such as Fischer-Tropsch wax. Is singly or 2
A mixture of two or more species may be used. Among these, carnauba wax, rice wax and candelilla wax are preferred from the viewpoint of compatibility with the binder resin, and carnauba wax is more preferred.

The melting point of the low-melting wax is 60 ° C. or more from the viewpoint of blocking resistance, and 9 from the viewpoint of low-temperature fixability.
0 ° C. or lower, preferably 70 to 85 ° C. In the present invention, a high melting point wax having a melting point exceeding 90 ° C., for example,
Polypropylene wax etc. may be mixed,
From the viewpoint of the minimum fixing temperature and durability, it is desirable that the low melting point wax is contained in the wax in an amount of 30% by weight or more, preferably 50% by weight or more, more preferably 80% by weight or more. In the present invention, the melting point of the wax refers to a differential scanning calorimeter (DSC2 manufactured by Seiko Instruments Inc.).
The temperature at the top of the endothermic peak obtained when the temperature is measured at a rate of 10 ° C./min using 10).

The content of the low-melting wax is determined from the viewpoints of blocking resistance, low-temperature fixability and durability.
The amount is preferably 1 to 10 parts by weight, more preferably 1 to 6 parts by weight, based on 0 parts by weight.

The negatively chargeable toner of the present invention is not particularly limited, and includes a pulverized toner, a polymerized toner, a capsule toner and the like. Therefore, the toner of the present invention can be produced by a known method such as a kneading and pulverizing method, a spray drying method, and a polymerization method. As a general method, for example, after uniformly mixing a binder resin, wax, and the like with a mixer such as a ball mill, melt kneading with a closed kneader or a single or twin screw extruder, cooling, pulverizing, Classification method may be mentioned. Further, a fluidity improver or the like may be added to the surface of the toner as needed. The weight average particle diameter of the toner thus obtained is preferably 3 to 10 μm.

Further, the negatively chargeable toner of the present invention includes a colorant, a conductivity adjuster, an extender, a reinforcing filler such as a fibrous substance, an antioxidant, an antioxidant, a fluidity improver, and a cleaning property. Additives such as an enhancer may be appropriately contained.

As the colorant, all dyes and pigments used as colorants for toner can be used. Carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine- B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, quinacridone, carmine 6B, disazo yellow, and the like, and these can be used alone or in combination of two or more. The content of the coloring agent is as follows.
The amount is preferably 1 to 10 parts by weight with respect to 00 parts by weight.

The negatively chargeable toner of the present invention is used alone as a developer when it contains a magnetic fine powder, as a non-magnetic one-component developer when it does not contain a magnetic fine powder, or mixed with a carrier. And is used as a two-component developer.

[0050]

[Example] [Acid value] Measured according to the method of JIS K0070.

[Softening point] The temperature at which half of the resin flows out is defined as the softening point using a Koka type flow tester (CFT-500D, manufactured by Shimadzu Corporation) (sample: 1 g, heating rate: 6 ° C.).
/ Min, load: 1.96MPa, nozzle: 1mmφ × 1m
m).

[Glass transition point] The temperature was raised at a rate of 10 using a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.).
Measure in ° C / min.

[Chloroform Insoluble Content] In a 100 cc glass bottle with a lid, 5 g of resin powder and radiolite “# 7
After adding 5 g of "00" (manufactured by Showa Chemical Industry Co., Ltd.) and 100 ml of chloroform and stirring at 25 ° C. for 5 hours in a ball mill, 5 g of radiolite was uniformly spread on the filter paper (manufactured by Toyo Roshi Kaisha, Ltd., No. 2 ). After the solid matter on the filter paper is washed twice with 100 ml of chloroform and dried, the insoluble content is calculated according to the following equation.

Insoluble content (% by weight) = (weight of solid on filter paper−radiolite 10 g) / 5 g × 100

Polyester [A-1, 3, B-1 to 3,
Examples of Production of C-1, 2, D-1] The raw materials of the polycondensation resin shown in Table 1 were prepared under nitrogen atmosphere by 22
The reaction was performed at 0 ° C., and the reaction was terminated when the softening point according to ASTM E28-67 reached a predetermined temperature. After cooling, pulverization was performed, and A-1, 3, B-1 to 3, C-1, 2 , D-1. Table 2 shows the acid value, softening point, glass transition point, and chloroform insoluble content of the obtained resin.

Production Example of Hybrid Resin [A-2] The starting materials for the polycondensation resin shown in Table 1 were mixed in a nitrogen atmosphere at 13
While stirring at 5 ° C., a raw material mixture of the addition polymerization resin shown in Table 1 was added dropwise over 4 hours. Aged for 5 hours while maintaining at 135 ° C., heated to 230 ° C. and reacted,
The reaction was terminated when the softening point by E28-67 reached a predetermined temperature, and after cooling, pulverized to obtain A-2. Table 2 shows the acid value, softening point, glass transition point, and chloroform insoluble content of the obtained resin.

[0057]

[Table 1]

BPA.PO: Polyoxyfluoro (2.2) -2,2-bis (4-human peroxyphenyl) fluoro BPA.EO: Polyoxyethylene (2.2) -2,2-bis (4-human peroxyphenyl) fluoro i -DSA: isododecenyl succinic anhydride TPA: terephthalic acid TMA: 1,2,4-benzenetricarboxylic anhydride AA: acrylic acid (bi-reactive monomer) FA: fumaric acid (bi-reactive monomer) DBO: dibutyl tin oxide (ester) Catalyst: St: Styrene EHA: 2-ethylhexyl acrylate DCP: Dicumyl peroxide (polymerization initiator)

[0059]

[Table 2]

Examples 1 to 7 and Comparative Examples 1 to 5 A total of 100 parts by weight of the binder resin shown in Table 3, a wax shown in Table 3, a negative charge control agent and a positive charge control agent, and carbon black After premixing 6 parts by weight of Mogal L (manufactured by Cabot Corporation), the mixture was melt-kneaded by a twin-screw extruder, cooled, pulverized and classified to obtain an untreated toner having a weight average particle diameter of 10 μm. Table 3 shows the acid values of the binder resins used in the examples and comparative examples.

To 100 parts by weight of the obtained untreated toner, 0.3 parts by weight of hydrophobic silica "H-2000" (manufactured by Wacker Chemical Co., Ltd.) was mixed and adhered using a Henschel mixer to obtain a toner.

Each of 39 parts by weight of the obtained toner was mixed with 1261 parts by weight of a ferrite powder (average particle size: 100 μm) coated with styrene / methyl methacrylate resin.
A developer containing each toner was obtained.

[0063]

[Table 3]

Test Example 1 A developer was modified from a copying machine (manufactured by Sharp Corporation, SF9800): the photosensitive member was made of amorphous selenium, the rotation speed of the fixing roller was set at 265 mm / sec, and the temperature of the fixing roller in the fixing device was changed. Is variable and the oil application device is removed), and the image is output while the temperature of the fixing roller is sequentially increased from 90 ° C. to 240 ° C.
The minimum fixing temperature and hot offset occurrence temperature were measured by the following methods. Table 4 shows the results.

(1) Minimum Fixing Temperature The image fixed with a load of 500 g was rubbed 5 times back and forth with a sand eraser having a size of 15 mm × 7.5 mm through a fixing machine, and the optical reflection density before and after rubbing was measured with a reflection densitometer. "RD
-915 "(manufactured by Macbeth), and the lowest fixing temperature is the temperature of the fixing roller whose ratio (after rubbing / before rubbing) initially exceeds 70%.

(2) Hot Offset Occurrence Temperature After an image is formed at each temperature, a blank transfer sheet is continuously fed to the fixing roller under the same conditions, and the temperature of the fixing roller at which toner smear first occurs on the blank sheet Is the hot offset occurrence temperature.

Test Example 2 10 g of toner was placed in a 100 ml glass bottle,
It was left for 2 weeks under environmental conditions of 0 ° C. and 26% relative humidity, and the blocking resistance was evaluated according to the following evaluation criteria.
Table 4 shows the results.

[Evaluation Criteria] A: No blocking was observed at all. X: Blocking was observed.

Test Example 3 The developer was mounted on a copying machine (SF9800, manufactured by Sharp Corporation), and an A4 original having a blackening ratio of 5% was continuously copied. The life of the developer is defined as the time when the fogging of the white portion of the copied paper can be visually confirmed, and the number of copies made up to that time is used as a measure of durability. The maximum number of copies is 150,000. Table 4 shows the results.

Test Example 4 The developer was mounted on a copying machine (SF9800, manufactured by Sharp Corporation), and 50,000 images were printed. At that time, a small amount of the developer was sampled after copying 100 sheets (initial printing) and after copying 50,000 sheets (after printing), and the charge amount of the toner was measured using a “q / m meter” (manufactured by Epping Corporation). Then, the chargeability was evaluated. Table 4 shows the results.

[0071]

[Table 4]

From the above results, the toners of Examples 1 to 7 have a low minimum fixing temperature, are excellent in all of the anti-offset properties, anti-blocking properties and durability, and maintain a stable negative charging property. We can see that we can do it.
In contrast, Comparative Example 1 containing only the high melting point wax
Toner has a high minimum fixing temperature and is inferior in stability and durability of the charge amount. Further, the toner of Comparative Example 2 containing the negatively chargeable charge control agent of the chromium complex showed a remarkable decrease in the charge amount due to printing, and the toner of Comparative Example 3 which did not contain the positively chargeable charge control agent exhibited an anti-charge property. The amount of charge of the toner increases due to printing, and the toner of Comparative Example 4, which does not contain the negatively chargeable charge control agent, shows a decrease in the amount of charge due to printing durability and has a remarkably poor durability. In the toner of Comparative Example 5 using a binder resin having an acid value of less than 10 mgKOH / g, the durability is reduced and the charge amount due to printing durability is reduced.

[0073]

According to the present invention, it is possible to provide a negatively chargeable toner having a low minimum fixing temperature, excellent offset resistance, blocking resistance and durability, as well as stable chargeability. became.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuichi Hirata 1334 Minato, Wakayama City, Kao Corporation Research Institute (72) Inventor Shinji Moriyama 1334 Minato, Wakayama City, Kao Corporation Research Institute F-term (reference) 2H005 AA01 AA06 CA08 CA13 CA14 CA17 CA21 CA22 CA25 CA28 DA02 DA03 EA03 EA07 EA10

Claims (5)

[Claims] 1. A negatively chargeable toner comprising a binder resin, a wax, a negatively chargeable charge control agent and a positively chargeable charge control agent, wherein the binder resin has an acid value of 10 mg KOH / g.
The wax has a melting point of 60 to 90 ° C., and the negatively chargeable charge control agent has the formula (I): (Wherein, R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a sulfonamide group, a sulfonic acid group, a carboxyester group, a hydroxy group, 18 represents an alkoxy group, an acetylamino group, a benzoylamino group or a halogen atom;
¹ and R ² may be the same or different, and X ¹ and X ² are a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an aryl having 6 to 10 carbon atoms. X ¹ and X ² may be the same or different, and A ⁺ represents a hydrogen ion,
A sodium complex ion, a potassium ion or an ammonium ion, and m and n each represent an integer of 1 to 3). 2. The negatively chargeable toner according to claim 1, wherein the positively chargeable charge control agent is a nigrosine dye. 3. A charge control agent having a positive charge / a metal complex salt compound represented by the formula (I) (weight ratio) of 1/99 to 50/50.
The negatively chargeable toner according to claim 1, wherein: 4. The negatively chargeable toner according to claim 1, wherein the binder resin is a polyester or a hybrid resin. 5. A binder resin having a softening point of 120 to 170 ° C.
Resin (A) having a glass transition point of 58 to 75 ° C and a chloroform insoluble content of 5 to 50% by weight, a softening point of 90 ° C or more and less than 120 ° C, a glass transition temperature of 58 to 75 ° C and a chloroform insoluble content of 5 The negatively chargeable toner according to any one of claims 1 to 4, further comprising a resin (B) that is less than about 10% by weight.