JP2000019784A - Minus charging toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of striped image unevenness without being fused to a feed roller, a layer regulating member and a toner carrier by containing polyester resin containing a urethane cross-linking component, and a specific compound. SOLUTION: A minus charging toner contains polyester resin containing a urethane cross-linking component, and a compound expressed by a formula. In the formula, X1 and X2 independently represent hydrogen atom, low alkyl group, low alkoxy group, nitro group or halogen atom, and X1 and X2 can be the same or different; (m) and m' independently represent integers of 1-3; R1 and R3 independently represent hydrogen atom, alkyl, alkenyl, sulfonated amide, mesyl, sulfonic acid, carboxy ester, hydroxy groups of C1-18, alkoxy, acetylamino, benzoylamino groups of C1-18 or halogen atom, and R1 and R3 can be the same or different; (n) and n' independently represent integers of 1-3; R2 and R4 represent hydrogen atom or nitro group; and A+ represents hydrogen ion, sodium ion, potassium ion or ammonium ion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negatively charged toner used for a printer or the like which uses a negatively charged electrophotographic photosensitive member and employs a non-magnetic one-component reversal developing method.

[0002]

2. Description of the Related Art At present, a negatively charged electrophotographic photosensitive member,
Particularly, a process of using an organic photoreceptor (OPC), writing a latent image on a negatively charged OPC with a light emitting diode (LED) or a semiconductor laser, and developing the latent image with a negatively charged toner is very generally used. Also,
As a developing method, a thin layer of toner is formed by a layer regulating member on a toner carrier, and a toner is developed by contacting the thin layer with a photoreceptor, because an inexpensive developing device can be provided. So-called non-magnetic one-component development methods have been used. As described above, many printers using the negatively charged OPC and adopting the non-magnetic one-component reversal developing method using the negatively charged toner have been commercialized.
In this method, there may be a problem such as a decrease in image density after initial use or a decrease in image density after long-term use, or an increase in streak-like image unevenness or an increase in image strength. In the non-magnetic one-component reversal developing method, toner is charged by friction by a toner supply roller or a layer regulating member. However, it is generally difficult to charge all toner particles to a sufficient level by this charging mechanism. Therefore, in the non-magnetic one-component reversal developing method, there is always a problem of ground fog. Further, in the non-magnetic one-component reversal developing method, the toner is subjected to a mechanical stress between the supply roller or the layer regulating member and the toner carrier. Tend to fuse, which may cause problems such as streak-like image unevenness and an increase in ground force blur. In order to solve these problems, the toner used in the non-magnetic one-component reversal developing method includes:
A polyester resin having the same molecular weight and a higher resin strength than a vinyl resin is used to improve the durability of the toner, and a specific charge control agent or an external additive is used to improve the chargeability of the toner. However, the above problem could not be fundamentally solved only by improving the chargeability by using a charge control agent or an external additive.

[0003]

Accordingly, the present invention is a novel negatively charged toner, and a toner used in a non-magnetic one-component reversal developing method with a negatively charged photoreceptor. An object of the present invention is to provide a negatively charged toner that does not fuse to a supply roller, a layer regulating member, and a toner carrier even when used, and does not cause problems such as generation of streak-like image unevenness and increase in ground force blur.

[0004]

The present invention is a negatively charged toner comprising a polyester resin containing a urethane crosslinking component and a compound represented by the following general formula (I).

Embedded image (Wherein X ₁ and X ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom;
₁ and X ₂ may be the same or different, m and m ′ represent an integer of 1 to 3, R ₁ and R ₃ represent a hydrogen atom,
Alkyl of ₁ to _18, alkenyl, sulfonamide, mesyl, sulfonic acid, carboxy ester, hydroxy, C
Alkoxy of ₁ to _18, acetylamino, represents a benzoylamino group or a halogen atom, R ₁ and R ₃ may be different even in the same, n and n 'represents an integer of 1 to 3, R ₂ And R ₄ represent a hydrogen atom or a nitro group;
⁺ Is hydrogen ion, sodium ion, potassium ion,
Represents ammonium ion. )

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyester resin containing a urethane cross-linking component used in the negatively charged toner of the present invention is obtained by subjecting a base polyester resin to urethane cross-linking with a diisocyanate and elongating the urethane to obtain a urethane cross-linked polyester resin. Can be obtained by mixing another polyester resin according to the above. As compared with a general polyester resin for a toner synthesized from a carboxylic acid and an alcohol, the polyester resin which is urethane cross-linked or extended by the above-mentioned diisocyanate has a tougher urethane bond than an ester bond in its molecular chain. Therefore, it is possible to improve the durability of the toner (prevention of fusion of the toner to the layer regulating member). The base polyester resin is obtained by polycondensation of a polycarboxylic acid and a polyhydric alcohol. Examples of the polycarboxylic acid include, for example, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, aliphatic dibasic acids such as hexahydrophthalic anhydride, maleic acid, maleic anhydride, fumaric acid, itaconic acid And aliphatic dibasic acids such as citraconic acid, aromatic dibasic acids such as phthalic anhydride, phthalic acid, terephthalic acid and isophthalic acid, and lower alkyl esters thereof. Examples of the polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol,
6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, hydrogenated bisphenol A, bisphenol A ethylene oxide adducts, diols such as bisphenol A propylene oxide adducts, and glycerin, trimethylolpropane, trimethylolethane, etc. Triol is used.

As the polycondensation method, there are known high-temperature polycondensation,
Solution polycondensation and the like are used. The usage ratio of the polyhydric carboxylic acid and the polyhydric alcohol is generally 0.8 to 1.4, which is the ratio of the former carboxyl group to the latter hydroxyl group.
The number average molecular weight of the base polyester resin is 100
It is from 0 to 30,000, preferably from 2000 to 15,000. If the number average molecular weight is less than 1,000, the offset resistance of the negatively charged toner may decrease, which is not preferable. If it exceeds 30,000, the viscosity of the reaction between the base polyester resin and the diisocyanate is remarkably increased, which is not preferable from the viewpoint of production, and the fixability of the negatively charged toner may be reduced. As the diisocyanate, for example, methylene diisocyanate, hexamethylene diisocyanate, isophone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate and the like are used. The usage range of the diisocyanate is 0.3 to 1 mol per mol of the base polyester resin.
0.95 mol, especially 0.5 to 0.8 mol, is preferred. If the diisocyanate is less than 0.3 mol, the offset resistance of the negatively charged toner may decrease. If it exceeds 0.95 mol, the viscosity increases significantly during the reaction, and in some cases, the viscosity of the urethane crosslinked polyesmol resin increases. This is not preferable in production because stirring cannot be performed.

The urethane crosslinked polyester resin is
For example, it is obtained by charging a base polyester resin with diisocyanate and reacting at a temperature of 50 to 150 ° C. for several hours in the presence or absence of a solvent. The other polyester resin is obtained by the same method as the base polyester resin, and has a number average molecular weight of 1,000 to 10
000, preferably 2000 to 6000. If the number average molecular weight is less than 1,000, the offset resistance of the negatively charged toner may decrease, and if it exceeds 10,000, the fixability may deteriorate. The polyhydric carboxylic acid and polyhydric alcohol used in the production of the other polyester resin may be the same as or different from the base polyester resin. In the polyester resin containing the urethane crosslinked component, the content ratio of the urethane crosslinked polyester resin to the other polyester resin is 20:80 to 9 by weight.
The ratio is 5: 5, preferably 30:70 to 80:20. When the content of the urethane crosslinked polyester resin is less than 20% by weight of the total, the offset resistance of the negatively charged toner is reduced. When the content of the other polyester resin is less than 5% by weight of the total, the negatively charged toner is Is unfavorable because the pulverizability in the manufacturing process of (1) deteriorates. The glass transition temperature (Tg) of the polyester resin containing the urethane cross-linking component is 40 to 80C, preferably 60 to 70C. When the glass transition temperature is lower than 40 ° C., the blocking property of the negatively charged toner may be deteriorated.
If the ratio exceeds the above, the fixability may be deteriorated. The polyester resin containing the urethane cross-linking component is a urethane cross-linking polyester resin alone or a solution containing the urethane cross-linking polyester resin, and a solution containing another polyester resin alone or another polyester resin is required in a predetermined ratio in a container. After heating and stirring and mixing according to the conditions, it is obtained by treating in a high-temperature vacuum in order to remove insoluble solvents, residual monomers and odor due to thermal degradation.

[0008] The negatively charged toner of the present invention contains a polyester resin containing the urethane crosslinking component and a compound represented by the following general formula (I).

Embedded image (Wherein X ₁ and X ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom;
₁ and X ₂ may be the same or different, m and m ′ represent an integer of 1 to 3, R ₁ and R ₃ represent a hydrogen atom,
Alkyl of ₁ to _18, alkenyl, sulfonamide, mesyl, sulfonic acid, carboxy ester, hydroxy, C
Alkoxy of ₁ to _18, acetylamino, represents a benzoylamino group or a halogen atom, R ₁ and R ₃ may be different even in the same, n and n 'represents an integer of 1 to 3, R ₂ And R ₄ represent a hydrogen atom or a nitro group;
⁺ Is hydrogen ion, sodium ion, potassium ion,
Represents ammonium ion. ) The above compound is commercially available, for example, from Hodogaya Chemical Company under the trade name: T-77. The content of the compound represented by the general formula (I) is preferably 1 part by weight or more and less than 3 parts by weight based on 100 parts by weight of the polyester resin containing the urethane crosslinking component. If the amount is less than 1 part by weight, it is difficult to obtain a sufficient image density due to an insufficient amount of triboelectricity of the toner, and the background fog in the non-image portion tends to increase. If the amount is more than 3 parts by weight, the background fog in the non-image portion tends to increase.

In the negatively charged toner of the present invention, a charge controlling agent such as a coloring agent or a metal-containing dye other than the compound represented by the general formula (I) may be used in combination as other components. Examples of the colorant include carbon black and color dyes and pigments generally used in toners. The colorant is used in an amount necessary and sufficient to maintain the optical density of the fixed image, and is usually 0.1 to 20 parts by weight based on 100 parts by weight of the resin.
Preferably, 0.2 to 10 parts by weight is added. In addition, release agents such as low molecular weight polypropylene and low molecular weight polyethylene, ferrite, magnetic agents such as magnetite, alumina,
An abrasive such as titanium oxide may be used in combination. Further, a fluidity improver such as silica fine particles and alumina fine particles may be attached to the surface of the toner particles of the present invention. In order to attach the fluidity improver to the surface of the toner particles, 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight of the fluidity improver may be added to 100 parts by weight of the toner and mixed.

The negatively charged toner of the present invention can be produced by stirring and mixing a polyester resin containing a urethane crosslinking component, a colorant, a charge control agent and other components, melt-kneading, cooling, and then pulverizing and classifying. . This toner has a roundness of 0.70 or more and 0.85 or less, and has a volume 50% diameter V of 6 to 10 μm in the Coulter counter method.
m, 0.5% by volume or less of toner particles having a particle size of 20 μm or more, and when the number% of the toner particles having a particle size of 5 μm or less is N, it is desirable that the following formula 1 is satisfied.

[Number 2] NV ² ≦ 1000 (1) Mechanical stress increases the durability of the toner roundness receives from layer regulating member and the toner carrying member to the toner when less than 0.70 of the toner is lowered, whereas If the roundness exceeds 0.85, the toner remaining on the photoreceptor without developing is difficult to clean, which is not preferable. Here, the circularity means that a toner particle is photographed by a transmission electron microscope, and the projected area (A) and the perimeter (B) of the particle are measured by an image analyzer (for example, EXCELII manufactured by Nippon Avionics Co., Ltd.). , From the following equation (2).

## EQU3 ## Roundness = (4πA) / B ² (2)

As a method of obtaining a toner having a roundness of 0.70 or more and 0.85 or less, a method of applying heat or impact force to the pulverized toner using a hybridizer manufactured by Nara Machinery Co., Ltd. A method using a pulverizer (Kryptron manufactured by Kawasaki Heavy Industries, Ltd., turbo mill manufactured by Matsubo, Cosmomizer manufactured by Nara Machinery Co., Ltd., etc.) can be used. Further, in the present invention, the particle diameter of the toner is expressed by the formula (1).
If the relationship is not satisfied, it is not preferable because a large number of prints tend to cause a reduction in image density, an increase in background fog, and streak-like image unevenness. That is, by satisfying the above expression (1), the number of particles having a particle diameter of 5 μm or less is reduced, and thereby the solid adhesion to the layer regulating member and the toner carrier due to the increase in the charge amount of the fine powder toner (this strong (Adhesion causes fusion of toner), thereby preventing a decrease in image density, an increase in background fog, and the occurrence of streak-like image unevenness, thereby prolonging the life of the developing unit.
The negatively charged toner of the present invention exposes an image portion of a photoconductor negatively charged by a charging member to form an electrostatic latent image, and forms a negatively charged image formed on the toner carrier by a layer regulating member on the toner carrier. It is suitably used in a non-magnetic one-component reversal developing method of developing a latent image by applying a bias voltage between a toner carrier and a photosensitive member while bringing a thin layer of toner into contact.

[0012]

EXAMPLES "Parts" in the following examples mean "parts by weight". Example 1 [Production of polyester resin containing urethane crosslinking component] In a polymerization vessel, 1700 parts of a propylene oxide adduct of bisphenol A, 150 parts of diethylene glycol,
860 parts of isophthalic acid were charged, and polycondensation was performed at 240 ° C. while introducing nitrogen into the polymerization vessel to obtain a base polyester resin. Next, the acid value of the base polyester resin is 5 mg.
When it becomes KOH / g or less, it is cooled to 130 ° C.
2500 parts of xylene and methylene diisocyanate 10
0 parts were charged and reacted at 120 ° C. for 4 hours to obtain a urethane crosslinked polyester resin. On the other hand, in another polymerization pot,
Bisphenol A propylene oxide adduct 1400
Parts, diethylene glycol 100 parts, isophthalic acid 80
0 parts and 50 parts of phthalic anhydride were charged and polycondensation was carried out at 230 ° C. while introducing nitrogen into the polymerization vessel to obtain another polyester resin. The urethane crosslinked polyester resin and another polyester resin were mixed in a xylene solvent at a ratio of 40:60, and the solvent was removed in a vacuum system to obtain a polyester resin (A) containing a urethane crosslinked component. GP (tetrahydrofuran) soluble portion of the polyester resin (A)
The molecular weight according to the C method was Mw = 168000, Mn = 39.
00, the acid value is 12 mg KOH / g, THF
The insoluble content was 5%. [Manufacture of toner] 100 parts of the above polyester resin (A)-2 parts of polypropylene wax (trade name: Viscol 550P manufactured by Sanyo Chemicals)-5 parts of carbon black (trade name: REGAL330R manufactured by Cabot Corporation)-The general formula (I) 2) (Product name: T-77, manufactured by Hodogaya Chemical Industry Co., Ltd.) The above-mentioned materials are stirred and mixed by a super mixer, and then melt-kneaded by a twin-screw kneading extruder, and then a cosmomizer manufactured by Nara Machinery Co., Ltd. And classified with an air classifier to obtain a classified product. 0.4 parts of hydrophobic silica fine particles (trade name: TS-530, manufactured by Cabot Corporation) was added to 100 parts of the classified product, and mixed with a Henschel mixer manufactured by Mitsui Mining Co., Ltd.
A negatively charged toner of the present invention was obtained. The volume 50% diameter (V) of the toner is 8.6 μm, the toner particles of 20 μm or more are 0.1 volume%, and the toner particles (N) of 5 μm or less are 1 volume%.
It was 1.2% by number and the roundness was 0.75. Thus, NV ² is 828.

Example 2 [Production of polyester resin containing urethane cross-linking component] In a polymerization vessel, 1700 parts of an adduct of bisphenol A propylene oxide, 150 parts of diethylene glycol,
860 parts of isophthalic acid were charged, and polycondensation was performed at 240 ° C. while introducing nitrogen into the polymerization vessel to obtain a base polyester resin. Next, the acid value of the base polyester resin is 5 mg.
When it becomes KOH / g or less, it is cooled to 130 ° C.
2500 parts of xylene and methylene diisocyanate 10
0 parts were charged and reacted at 120 ° C. for 4 hours to obtain a urethane crosslinked polyester resin. On the other hand, in another polymerization pot,
Bisphenol A propylene oxide adduct 1400
Parts, diethylene glycol 100 parts, isophthalic acid 60
0 parts and 30 parts of phthalic anhydride were charged, and polycondensation was carried out at 230 ° C. while introducing nitrogen into the polymerization vessel to obtain another polyester resin. The urethane crosslinked polyester resin and another polyester resin were mixed in a xylene solvent at 40:60, and the solvent was removed in a vacuum system to obtain a polyester resin (B) containing a urethane crosslinked component. The molecular weight of the THF-soluble component of the polyester resin (B) by GPC method is M
w = 152000, Mn = 3400, and the acid value is 10
mgKOH / g, and the THF insoluble content was 3%. [Manufacture of toner] 100 parts of the above polyester resin (B)-2 parts of polypropylene wax (trade name: VISCOL 550P manufactured by Sanyo Kasei Co., Ltd.)-6 parts of carbon black (trade name: REGAL330R manufactured by Cabot Corporation)-The general formula (I) ) 2 parts (trade name: T-77, manufactured by Hodogaya Chemical Industry Co., Ltd.) The above-mentioned materials are stirred and mixed by a super mixer, and then melt-kneaded by a twin-screw kneading extruder. It was pulverized by a mold jet mill and classified by an air classifier to obtain a classified product. The classified product was put into a hybridizer type 1 manufactured by Nara Machinery Co., Ltd., and treated at 6400 rpm for 4 minutes. Hydrophobic silica fine particles (trade name: TS-530, manufactured by Cabot Corporation) 0.4 per 100 parts of the treated product
Were mixed with a Henschel mixer manufactured by Mitsui Mining Co., Ltd. to obtain a negatively charged toner of the present invention. The volume 50% diameter (V) of the toner is 7.8 μm, the toner particles of 20 μm or more are 0 volume%, and the toner particles (N) of 5 μm or less are 1 volume%.
4.6% by number and roundness was 0.77. Thus, NV ² is 888.

Example 3 A negatively charged toner of the present invention was obtained in the same manner as in Example 1 except that the content of the compound represented by the formula (I) was changed to 0.5 part. The 50% volume diameter (V) of this toner is 8.4 μm.
m, toner particles having a particle size of 20 μm or more were 0% by volume, toner particles (N) having a particle size of 5 μm or less were 12.6% by number, and the roundness was 0.74. Thus, NV ² is 889.

Example 4 A negatively charged toner of the present invention was obtained in the same manner as in Example 1 except that the content of the compound represented by the general formula (I) was changed to 3.5 parts. The 50% volume diameter (V) of this toner is 8.5 μm.
m, toner particles having a particle size of 20 μm or more were 0% by volume, toner particles (N) having a particle size of 5 μm or less were 12.0% by number, and the roundness was 0.75. Thus, NV ² is 867.

Example 5 A negatively charged toner of the present invention was obtained in the same manner as in Example 1 except that the classification conditions were changed. The volume 50% diameter (V) of the toner is 8.3 μm, the toner particles having a volume of 20 μm or more are 0.1 volume%, and the toner particles having a volume of 5 μm or less (N)
Was 20.2% by number and the roundness was 0.74.
Thus, NV ² is 1392.

Example 6 A negatively charged toner of the present invention was obtained in the same manner as in Example 2, except that the hybridizer process manufactured by Nara Machinery Works was omitted. The 50% volume diameter (V) of this toner is 7.
0 volume%, 5 μm
The following toner particles (N) were 13.4% by number and circularity was 0.66. Thus, NV ² is 836.

Comparative Example 1 100 parts of a polyester resin containing no urethane cross-linking component (THC-insoluble content: 8%, THF-soluble content: GPC method: Mw = 97000, Mn = 3600, acid value: 15 mgKOH / G) ・ 2 parts of polypropylene wax (trade name: Viscol 550P, manufactured by Sanyo Chemicals) ・ 5 parts of carbon black (trade name: REGAL330R, manufactured by Cabot) ・ 2 parts of the compound represented by the general formula (I) (Hodogaya Chemical Industry Co., Ltd.) Product name: T-77) The above materials are stirred and mixed with a super mixer, then melt-kneaded with a twin-screw kneading extruder, pulverized with a cosmomizer manufactured by Nara Machinery Co., Ltd., and classified with an air classifier. To obtain a classified product. 0.4 parts of hydrophobic silica fine particles (trade name: TS-530, manufactured by Cabot Corporation) was added to 100 parts of the classified product, and mixed with a Henschel mixer manufactured by Mitsui Mining Co., Ltd.
A negatively charged toner for comparison was obtained. The volume 50% diameter (V) of the toner is 8.9 μm, the toner particles of 20 μm or more are 0 volume%, and the toner particles (N) of 5 μm or less are 10.
2% by number and the roundness was 0.72. Therefore,
NV ² is 808.

Comparative Example 2-100 parts of the polyester resin (A)-2 parts of polypropylene wax (trade name: Viscol 550P, manufactured by Sanyo Chemicals)-5 parts of carbon black (trade name: REGAL330R, manufactured by Cabot Corporation)-Chromium complex compound 2 Part (trade name: Bontron S-34, manufactured by Orient Chemical Co., Ltd.) The above-mentioned materials are stirred and mixed by a super mixer, then melt-kneaded by a twin-screw kneading extruder, and pulverized by a cosmomizer manufactured by Nara Machinery Co., Ltd. Classification was performed using an air classifier to obtain a classified product. 0.4 parts of hydrophobic silica fine particles (trade name: TS-530, manufactured by Cabot Corporation) was added to 100 parts of the classified product, and mixed with a Henschel mixer manufactured by Mitsui Mining Co., Ltd.
A negatively charged toner of the present invention was obtained. The volume 50% diameter (V) of the toner is 8.8 μm, the toner particles of 20 μm or more are 0.2 volume%, and the toner particles (N) of 5 μm or less are 1 volume.
It was 2.0 number% and the roundness was 0.72. Thus, NV ² is 929.

Next, the toners of Examples 1 to 6 and Comparative Examples 1 and 2 were loaded into a commercially available nonmagnetic one-component reversal developing method printer having a negatively charged OPC (product name: Multiwriter 2400 manufactured by NEC). Then, a printing test was performed with a test pattern having a printing rate of 5%. Initial image of printing and 500
Table 1 shows the result of the image after the zero sheet. In the table, ID is the reflection density of a solid image measured by a Macbeth reflection densitometer (RD-914), and BG is the difference in Hunter whiteness of the non-image portion between the paper before printing and the same paper after printing. Show. Also,
OPC fog is the average value of the reflection densities measured at nine points using a Macbeth reflection densitometer (RD-914) after transferring the ground fog on the OPC photoreceptor to a mending tape manufactured by Scotch Co., Ltd., and pasting it on white paper. is there.

[0021]

[Table 1]

As shown in Table 1, the negatively charged toners of Examples 1 and 2 have a practically sufficient ID value from the beginning and have a BG
Value and OPC fog are low, have good image characteristics even after printing 5,000 sheets, have no toner fusion to the layer regulating member and the toner carrier, and do not cause streak-like image unevenness. there were. In contrast, Example 3
The negatively charged toner has a slightly lower ID value from the beginning than that of Examples 1 and 2 and has many BG values and OPC fog, and a decrease in the ID value was confirmed after printing 5000 sheets. The negatively charged toner of Example 4 is the same as that of Examples 1 and 2
From the beginning, the BG value and the OPC fog were also slightly higher from the beginning, and the increase of the BG value was confirmed after printing 5,000 sheets. The negatively charged toner of Example 5 is the same as that of Examples 1 and 2
After printing 5000 sheets, the ID value slightly decreased and the BG value increased, and further, unevenness was observed in the halftone portion of the image. Although the negatively charged toner of Example 6 was not so inferior in ID value and BG value as compared with Examples 1 and 2, unevenness was observed in the halftone image after printing 5,000 sheets. The BG value of the negatively charged toner of Comparative Example 1 was higher than that of Examples 1 and 2 from the beginning, and streaks were confirmed in the halftone image after printing 5,000 sheets. The BG value of the negatively charged toner of Comparative Example 2 was higher than that of Examples 1 and 2 from the beginning, and the ID value was slightly lowered after printing 5,000 sheets.

[0023]

The negatively charged toner of the present invention does not fuse to the supply roller, the layer regulating member and the toner carrier even when used for a long period of time, and causes problems such as the occurrence of streak-like image unevenness and an increase in ground force blur. Will not occur.

Claims (4)

[Claims] 1. A negatively charged toner comprising a polyester resin containing a urethane crosslinking component and a compound represented by the following general formula (I). Embedded image (Wherein X ₁ and X ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom;
₁ and X ₂ may be the same or different, m and m ′ represent an integer of 1 to 3, R ₁ and R ₃ represent a hydrogen atom,
Alkyl of ₁ to _18, alkenyl, sulfonamide, mesyl, sulfonic acid, carboxy ester, hydroxy, C
Alkoxy of ₁ to _18, acetylamino, represents a benzoylamino group or a halogen atom, R ₁ and R ₃ may be different even in the same, n and n 'represents an integer of 1 to 3, R ₂ And R ₄ represent a hydrogen atom or a nitro group;
⁺ Is hydrogen ion, sodium ion, potassium ion,
Represents ammonium ion. ) 2. The polyester resin 10 containing a urethane cross-linking component, which contains the compound represented by the general formula (I).
2. The negatively charged toner according to claim 1, wherein the amount is not less than 1 part by weight and less than 3 parts by weight based on 0 part by weight. 3. An electrostatic latent image is formed by exposing an image portion of a photoreceptor negatively charged by a charging member to form an electrostatic latent image on the photoreceptor. A negatively charged toner used in a non-magnetic one-component reversal developing method in which a latent image is developed by applying a bias voltage between a toner carrier and a photoreceptor while the layers are in contact with each other; With respect to 100 parts by weight of a polyester resin containing
Negatively charged toner, comprising 1 to 3 parts by weight of a compound consisting of Embedded image (Wherein X ₁ and X ₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom;
₁ and X ₂ may be the same or different, m and m ′ represent an integer of 1 to 3, R ₁ and R ₃ represent a hydrogen atom,
Alkyl of ₁ to _18, alkenyl, sulfonamide, mesyl, sulfonic acid, carboxy ester, hydroxy, C
Alkoxy of ₁ to _18, acetylamino, represents a benzoylamino group or a halogen atom, R ₁ and R ₃ may be different even in the same, n and n 'represents an integer of 1 to 3, R ₂ And R ₄ represent a hydrogen atom or a nitro group;
⁺ Is hydrogen ion, sodium ion, potassium ion,
Represents ammonium ion. ) 4. A toner having a roundness of 0.70 or more and 0.85 or more.
The following is the volume 50 in the Coulter counter method.
The toner particles having a% diameter V of 6 to 10 µm and 20 µm or more are 0.5% by volume or less, and when the number% of 5 µm or less is N, the following formula 1 is satisfied. 3. The negatively charged toner according to any one of 3. [Expression 1] NV ² ≦ 1000 (1)