JPH0260185B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel dry negatively charged toner for developing electrostatic latent images in electrophotography, electrostatic recording, electrostatic printing, and the like. Originally, an electrostatic latent image can be developed and visualized by adhering toner due to its electrostatic attraction, but as a developer for this electrostatic latent image, in addition to liquid developer, powder developer agents are widely used. This powder developer is a mixture of a toner with an average particle size of 15 μm, which is made by dispersing colorants, charge control agents, fluidizing agents, etc. in natural or synthetic resin, and a carrier such as iron powder or ferrite powder with a diameter of 100 to 200 μm. A two-component developer consisting of a natural resin or a synthetic resin, a coloring agent, a charge control agent, a fluidizing agent, and a magnetic material.
It can be broadly classified into component type developers. A two-component developer achieves development by attaching charged toner to an electrostatic latent image through friction with a carrier. Conventionally, a one-component developer uses a toner instead of a carrier. Toner that is charged by friction with a brush-like or plate-like friction member that has a similar function is known, and recently, toner that is charged by friction with a brush-like or plate-like friction member has been developed. It has become known that toner is charged by mutual friction with powder. These developing toners are kept positively or negatively charged depending on the polarity of the electrostatic latent image to be developed. In order to keep the toner charged, it has been proposed to utilize the triboelectricity of the resin, which is the main component of the toner, but this method has a small charge on the toner and a large solid surface resistance value, so The resulting image is prone to fogging and becomes unclear. Therefore, in order to impart the desired triboelectricity to the toner,
Dyes, pigments, and even charge control agents that impart a charge are added to the toner.Currently, the ones that are used in this technical field include those that impart a positive charge to the toner. There are oil-soluble dyes such as nigrosine, which are shown in Publication No. 2427 of the 1970s, etc., and those that impart a negative charge are listed in Japanese Patent Publication No. 41-2427.
No. 20153, Special Publication No. 17955, Special Publication No. 45-26478
There are metal-containing complex salt dyes as disclosed in Japanese Patent Application Laid-Open No. 52-67331, Japanese Patent Application Laid-Open No. 59-29253, and the like. However, the charge control agents disclosed in these publications (1) have a small charge amount per unit (｜25｜
μC/g or less), (2) low bulk (3.0cc/g or less), (3)
It has disadvantages such as poor crushability (more than 10% remains at 350mesh). As a result of extensive research into compounds that do not have the above-mentioned drawbacks and can impart negative charge to toner, the inventors found that the general formula (In the formula, R ₁ represents a nitro group or a halogen, R ₂ represents hydrogen, a nitro group, or a halogen, and R ₁ and R ₂ may be the same or different. _{R 3} is , hydrogen or alkyl group ( _C1 - _C6 )
shows. M represents Cr, Co or Fe. The present invention was completed based on the discovery that the metal complex compound represented by the following is particularly excellent. The metal complex compound in the present invention is obtained by treating a metallizable azo compound with a metallizing agent by a known method, and then diluting with water containing acid or mineral acid to precipitate it, if necessary, and filtering it out. obtained by Examples of the diazo component used to obtain the metallizable azo compound in the present invention include 3-chloro-2-aminophenol, 4-chloro-2-aminophenol, 5-bromo-2-aminophenol, 3,5 -dichloro-2-aminophenol, 5-nitro-2-aminophenol, 4-nitro-2-aminophenol, 4,6-dinitro-2-aminophenol, and the like. Next, examples of coupling components used to obtain metallizable azo compounds include 2-oxy-3-naphthoic acid, alkyl (C ₁ -C ₆ )-2-
Examples include oxy-3-naphthoic acid. Furthermore, organic or inorganic chromium salts, cobalt salts, and iron salts can be used as metallizing agents for treating the metallizable azo compound. The counter ion in this case can be obtained as a hydrogen ion (H ⁺ ), for example, by setting the pH before filtration to 3 or less and washing after filtration until the pH reaches 6 to 7. Specific examples of the metal complex compound represented by the general formula () of the present invention are illustrated, and their physical properties are described below.

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[Table] (Note) Method for evaluating physical properties Charge amount: Precisely weigh 1 g of sample and 50 g of carrier (manufactured by Nippon Steel Powder Co., Ltd., TEFV200/300) in a 100 c.c. plastic bottle, mix thoroughly, and blow off (manufactured by Toshiba Chemical Co., Ltd.) ) The amount of charge was measured. Bulk: According to JIS K-5101-18. Grindability: 15 g of the sample was placed in a tabletop grinder (Nippon Rikagaki Kikai Co., Ltd., analytical grinder R-8), ground for 3 minutes, and measured using a 350 mesh standard sieve. value is,
Represents % of 350mesh sieve residue. The above metal complex compounds used in the present invention have excellent chargeability (｜30｜μC/g or more) and high bulk (5.0 μC/g or more).
cc/g or more), has excellent pulverization properties (1% or less), and has extremely good dispersibility in toner resins. Incidentally, the amount of the metal complex compound of general formula () added to the toner component is 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the resin. The toner of the present invention is made by adding a known toner resin and colorant in addition to the metal complex compound represented by the above general formula (). Examples of the toner resin include:
Styrene resins, styrene-acrylic resins, styrene-butadiene resins, epoxy resins, polyester resins, paraffin waxes, and low-polymerized polypropylenes may be used, and one or more of these may be used in combination. Further, as the coloring agent, a large number of known dyes and pigments can be used. When the toner of the present invention is mixed with a carrier to form a two-component developer, any known carrier can be used. Further, when forming a developer as a one-component toner, it is possible to knead it with a known magnetic powder (for example, magnetite). EXAMPLES Specific examples of the present invention will be described below in Examples. In addition, in the examples, parts by weight are abbreviated as parts. Example 1 Styrene-acrylic copolymer 100 parts (manufactured by Sanyo Kasei Co., Ltd., Hymer SMB600) Carbon black...5 parts (manufactured by Mitsubishi Kasei Co., Ltd., #44) Complex compound of compound example (1) ...1 part The above compound Pre-mix evenly with a ball mill,
Prepare premixes. Next, the mixture was melt-kneaded using hot rolls, cooled, and then coarsely ground using a vibration mill, and further finely ground using an air jet mill. The obtained fine powder was classified to obtain a black toner having a particle size of 5 to 15 μm. A developer was prepared by mixing 97 parts of iron powder carrier (manufactured by Nippon Tetsuko Co., Ltd., TEEV200) with 3 parts of the obtained toner.The initial blow-off charge amount of this developer was -30.1 μC/g. Ta. When a toner image was formed using this developer using a magnetic brush development method on a commercially available selenium drum, it was found that a toner image with no fog and good fine line reproducibility was obtained.
Moreover, a clear black image with a solid area reflection density of 1.5 or higher was obtained. Also, for a long period of time (10000 sheets)
Even after repeated use over a period of time, stable copied images were obtained without any change. Example 2 Polyester resin...100 parts (ATR-200 manufactured by Kao Soap Co., Ltd.) Blue dye...2 parts (manufactured by Orient Chemical Industry Co., Ltd., Valifast
Blue2606) Blue pigment...4 parts (copper phthalocyanine) Complex compound of compound example (2)...0.5 part The above formulation was treated in the same manner as in Example 1 to prepare a blue toner. A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -28.2 μC/g. When this developer was copied in the same manner as in Example 1, a blue image with no fog and good fine line reproducibility was obtained, and even after repeated use over a long period of time (10,000 sheets), a copied image remained unchanged. I was able to do it. Example 3 A toner was prepared in the same manner as in Example 2 except that 0.5 part of the complex compound of Compound Example (3) was used in place of the complex compound of Compound Example (2) in Example 2.
A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -29.6 μC/g. When this developer was copied in the same manner as in Example 2, a blue image with no fog and good fine line reproducibility was obtained.
Even after repeated use over a long period of time (10,000 copies), it is possible to obtain stable copied images without any change. Example 4 Epoxy resin...100 parts Epicoat 1004, manufactured by Ciel Chemical Co., Ltd.) Carbon black...6 parts (#44, manufactured by Mitsubishi Kasei Corporation) Complex compound of compound example (4)...1 part The above formulation was used as an example A black toner was prepared in the same manner as in Example 1. A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -26.1 μC/g. When copies were made using this developer in the same manner as in Example 1, clear black images with no fog and good fine line reproducibility were obtained. In addition, even after repeated use over a long period of time (10,000 copies), stable copied images were obtained without any change. Comparative Example 1 A black toner was prepared in the same manner as in Example 1 except that 1 part of the complex compound of Comparative Example (1) was used in place of the complex compound of Compound Example (1) in Example 1. .
A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -10.1 μC/g. When copies were made using this developer in the same manner as in Example 1, unclear images with a lot of fog were obtained even in the initial copies. Comparative Example 2 A black toner was prepared in the same manner as in Example 1 except that 1 part of the complex compound of Comparative Example (2) was used in place of the complex compound of Compound Example (1) in Example 1. .
A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -8.2 μC/g. When copies were made using this developer in the same manner as in Example 1, unclear images with a lot of fog were obtained even in the initial copies. Comparative Example 3 A black toner was prepared in the same manner as in Example 1 except that 1 part of the complex compound of Comparative Example (3) was used in place of the complex compound of Compound (1) in Example 1.
A developer was prepared by mixing 97 parts of iron powder carrier with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -17.9 μC/g. When copies were made in the same manner as in Example 1 using this developer, the fine line reproducibility of the image was inferior to that in Example 1. Comparative Example 4 A black toner was prepared in the same manner as in Example 1 except that 1 part of the complex compound of Comparative Example (4) was used in place of the complex compound of Compound Example (1) in Example 1. . 97% iron powder carrier for 3 parts of the toner obtained
A developer was prepared by mixing the two parts. The initial blow-off charge amount of this developer was -14.7 μC/g. When copies were made in the same manner as in Example 1 using this developer, there was more fog and the fine line reproducibility of the image was poorer than in Example 1.

Claims (1)

[Claims] 1 General formula K1260 (wherein R ₁ represents a nitro group or a halogen, R ₂ represents hydrogen, a nitro group or a halogen, and R ₁ and R ₂ may be the same) _R3 is hydrogen or an alkyl group ( _C1 to _C6 ).
shows. M represents Cr, Co or Fe. ) A toner for developing an electrostatic image, characterized by containing a metal complex compound represented by the following as a charge control agent.