JPH10239908A - Negatively chargeable toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the toner using a negative charge controller capable of exhibiting an excellent effect by small addition and exhibiting a white color or a light color especially adapted to color printing, and using no metal compound having problems on toxicity indicated. SOLUTION: The charge controller to be used for this toner as the negative charge controller is an aminobenzenesulfonamido compound, such as 2- aminobenzenesulfonamido, N,N-dimethylsulfanylamido, 4- dimethylaminobenzenesulfonamido, 2-benzylamino-N-benzylbenzenesulfonamido, 2-benzylamino-N-benzylbenzenesulfonamido, 4-phenylaminobenzenesulfonanilido, 5-amino-2-chloro-2', 4'-dimethylbenzenesulfonanilido, or 2,5-methoxysulfanylamido.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negatively charged toner used for developing an electrostatic latent image in electrophotography or electrostatic printing. . [0002] Generally, a toner for developing an electrostatic latent image is prepared by adding a coloring agent such as a dye or a pigment and a positive or negative charge to a binder resin such as a styrene resin, an epoxy resin or a polyester resin. After dispersing the charge control agent to be applied, it is finely pulverized to an average particle size of about 10 to 15 μm and adjusted. In addition, as a special production method, a method of applying a pigment or a charge control agent by applying a mechanochemical reaction to the surface of particles made of a binder resin, or a method of applying a pigment or a charge control agent to a monomer which is a raw material of the binder resin. A method of producing a spherical toner by a suspension polymerization reaction after dispersion is also known. Conventionally, as a charge control agent added to a negatively chargeable toner, a metal complex salt of a monoazo dye or a non-dye type metal complex is known. As a charge control agent for a negatively chargeable toner, one using a metal complex salt such as cobalt or chromium is disclosed in
-29253, 59-78361, 59-2282
Nos. 59, 61-160763 and 63-38959 using a zinc complex are disclosed in JP-A-61-73396.
Japanese Patent Application Laid-Open No. 5-34986 discloses a device using a tin compound and Japanese Patent Application Laid-Open No. 7-286106 discloses a device using an iron complex. Among the known negative charge control agents, metal complex salts of monoazo dyes and metal complexes of salicylic acid, naphthoic acid or dicarboxylic acid such as cobalt, chromium and iron are known. It is generally unsuitable for color toners other than black because it has a complex structure and strong coloring properties.It also degrades due to decomposition during heat kneading or changes in temperature and humidity during storage, resulting in charge control properties. Is easy to vary,
In addition, since it is extremely difficult to disperse the toner in a thermoplastic resin, it is not possible to obtain a toner having stable and uniform chargeability. Further, those containing a metal such as chromium have problems of stable hygiene at the time of production and use of the toner and problems of environmental pollution at the time of disposal. It is an object of the present invention to use a metal complex or the like which has been pointed out as having a problem of toxicity.
An object of the present invention is to provide a negatively chargeable charge control agent which exhibits a white or light color suitable for color printing as well as a black print toner, and which can achieve a desired charge control effect with a small amount of addition. Means for Solving the Problems The inventors of the present invention have conducted intensive studies and studies in view of such circumstances, and as a result, as a charge controlling agent, aminobenzene sulfone represented by the following general formula (2) The inventors have found that the amide compound has the desired charge control performance when using an amide compound, and have completed the present invention. [0007] Wherein R ₁ and R ₂ are a hydrogen atom, an alkyl group, a substituted alkyl group or an aryl group, R ₃ and R ₄ are a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group or an acyl group, R ₅ and R ₆ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, an alkoxy group or a nitro group. [0008] Representative examples of the aminobenzenesulfonamide compound represented by the formula (2) suitable for carrying out the present invention include 2-aminobenzenesulfonamide, 3-aminobenzenesulfonamide, and 4-aminobenzenesulfone. Amide (sulfanylamide), N1-hexadecylsulfanylamide, N1, N1-dimethylsulfanylamide, N1-methylmethanilanilide, N1-cyclohexylmethanilamide, 4-dimethylamino-N, N-
Dimethylbenzenesulfonamide, 2-benzylamino-N-benzylbenzenesulfonamide, 4-phenylaminobenzenesulfonanilide, 4-amino-N, N
-Bis (2-hydroxyethyl) benzenesulfonamide, N4-acetylsulfanylanilide, 5-amino-2-chloro-2 ', 4'-dimethylbenzenesulfonanilide, 2,6-dibromosulfanylamide, 3,
5-dichloro-N, N-dimethylsulfanilamide,
2-methyl-3-aminobenzenesulfonamide, 3-
Benzylsulfanylamide, 3-phenyl-5-chlorosulfanylamide, 2,5-dimethoxysulfanylamide, 2,5-dimethoxysulfanylanilide,
Examples thereof include 3-amino-N1-cyclohexyl-4- (hexadecyloxy) benzenesulfonamide and 4- (methylamino) -N-methyl-3-nitrobenzenesulfonamide. DESCRIPTION OF THE PREFERRED EMBODIMENTS The aminobenzenesulfonamide compound in the negatively charged toner of the present invention should be added to the toner in an amount of 0.5 to 10% by weight, preferably 1.0 to 5.0% by weight. When the amounts of these components are small, the charge amount of the toner becomes insufficient. On the contrary, when it is too large, the charge amount of the toner changes with time, and the charge control effect becomes unstable. In carrying out the present invention, a conventionally used negatively chargeable charge control agent may be used in combination. A typical binder resin suitable for practicing the present invention is a copolymer resin of styrene and acrylate, and other polystyrene resin, polypropylene resin, polyethylene resin, polyamide resin, polyurethane resin, phenol resin. Resin, polyester resin,
Polycarbonate resins and the like, and mixtures of two or more thereof can be used. As the coloring agent, various known coloring agents can be used. For example, carbon black or nigrosine dye for black toner, rhodamine pigment or quinacdrine pigment for red toner, copper phthalocyanine pigment or anthracene derivative dye for blue toner, benzene yellow for yellow toner, etc. The use of colorants is possible. Further, the negatively chargeable toner of the present invention can be used as a magnetic toner by containing a magnetic material. Magnetic materials added to the magnetic toner include magnetite, hematite, iron oxides such as ferrite, iron,
Metals such as cobalt and nickel or alloys containing these. These magnetic materials have an average particle size of 0.1 to
It is preferably about 2 μm, and the amount contained in the toner is 4 parts by weight based on 100 parts by weight of the binder resin component.
0 to 150 parts by weight is suitable. In practicing the present invention, known additives for improving image characteristics can be blended in addition to the above-mentioned compounds. For example, a fluidizing agent such as colloidal silica, an abrasive such as strontium titanate and silicon carbide, a lubricant such as metal stearate, and a conductivity imparting agent such as tin oxide can be added. The preparation of the negatively chargeable toner of the present invention can be performed by a known method. The most common method is to appropriately mix an amide compound, a colorant and other additives into a binder resin, and then sufficiently knead, coarsely and finely pulverize the mixture using a hot roll, a kneader or an extruder to obtain a granule. A particle having a diameter of 45 μm or less, preferably 4 to 20 μm,
It may be 15 μm. Hereinafter, the present invention will be described in detail with reference to examples. [Examples 1 to 14] Styrene-acrylate copolymer resin [Fujikura Kasei Co., Ltd .:
S-708F] 92 parts by weight, 5 parts by weight of carbon black (MA100, manufactured by Mitsubishi Chemical Corporation) as a coloring agent, and 3 parts by weight of the aminobenzenesulfonamide compound shown in Table 1 as a charge controlling agent were mixed. Dry blend with a mixer and then use a twin screw extruder to
Kneaded at a temperature of ~ 160 ° C, cooled after extrusion, crushed into a plate, crushed in a mortar, finely crushed using a desktop crusher, and then passed through a stainless steel sieve with an aperture of 44 µm. To prepare a sample. 1 g of the sample and 25 g of iron powder as a carrier (DSP-128B, manufactured by Dowa Iron Powder Co., Ltd.)
After placing it in a polyethylene jar with a capacity of 0 ml and stirring and shaking on a rotating roll of a roll mill for 5 minutes or 30 minutes, the charge amount was measured using a blow-off type charge amount measuring device. As shown in Table 1. The measurement conditions of the charge amount were as follows: 200 mg of a mixture of a sample and a carrier, and a blow pressure of 1 kg /
cm ² , measurement time 30 seconds, the unit of the measured value is sample 1
It was expressed in μC per g (10 ⁻⁶ coulomb). [Table 1] According to the present invention, a stable and high negative charge control effect can be obtained by adding a small amount of a charge control agent, and the charge control agent is white or light color. Of course, it is excellent as an electrophotographic toner for color printing and the like, and has a great effect in use, for example, it can avoid the use of a metal compound whose toxicity is pointed out.

Claims (1)

Claims: 1. A negatively charged toner comprising an aminobenzenesulfonamide compound represented by the following general formula as a charge control agent. Embedded image Wherein R ₁ and R ₂ are a hydrogen atom, an alkyl group, a substituted alkyl group or an aryl group, R ₃ and R ₄ are a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group or an acyl group, R ₅ and R ₆ Represents a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, an alkoxy group or a nitro group.