JP2523305B2 - Developer composition for electrostatic image - Google Patents

Description

TECHNICAL FIELD The present invention relates to a developer used for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing and the like. More specifically, the present invention relates to a developer composition containing a positively charged toner for a dry developer or a carrier for a dry developer.

2. Description of the Related Art In electrophotography, a photoconductive substance such as selenium is used as a photoconductor, an electric latent image is formed by various means, and a magnetic brush developing method is used for the latent image. A method in which toner is adhered and visualized is generally adopted.

In the developing step, carrier particles called a carrier are used to give an appropriate amount of positive or negative electric charge to the toner, and a method of obtaining an electric charge by friction, recently, a magnetic fine powder is added to the toner, A frictional charging method using a brush-shaped or plate-shaped frictional member having a charging ability or a charging ability by mutual friction between them is known. The developing toner used therein must carry a positive or negative charge depending on the polarity of the electrostatic latent image to be developed. A conventional developer toner is obtained by melt-kneading a thermoplastic resin with a pigment such as carbon black, then pulverizing and classifying the toner to obtain a developing toner, and utilizing the triboelectric charging property of the resin as the main component of the toner, It was an attempt to satisfy the conditions. However, since the developing toner obtained by this method has a low charging property, it has a problem in image characteristics such as fogging and a short life. Therefore, in order to solve these problems, a charge control agent is added to the toner to impart chargeability.

Problems to be Solved by the Invention Among those recently proposed, examples of the charge control agent to be imparted with a positive charge include nigrosine dyes, and the dyes of this system are usually added to the binder resin. Since it is difficult to uniformly melt and disperse the toner, the resulting toner particles have different charge amounts, resulting in an extremely wide charge amount distribution and poor stability.

Therefore, it is an object of the present invention to provide a developer composition for electrostatic images in which the above-mentioned drawbacks are improved.

Means and Actions for Solving Problems The above object of the present invention is to provide the following general formula: (In the formula, R is a hydrogen atom, a substituted or unsubstituted alkyl group,
Or a halogen atom) which is a metal complex of an aromatic oxyaldehyde represented by the formula (4) can be included in the developer composition.

 Hereinafter, the present invention will be described in detail.

In the present invention, examples of the metal complex of the aromatic oxyaldehyde represented by the above general formula used as the charge control agent include the following.

2-Hydroxy-1-naphthaldehyde manganese complex 2-Hydroxy-1-naphthaldehyde cobalt complex 3-Chloro-2-hydroxynaphthaldehyde manganese complex Metal complexes of these aromatic oxyaldehydes can be prepared by known methods. Can be synthesized by. For example, taking the case of a manganese complex of 2-hydroxy-1-naphthaldehyde as an example, the synthesis is as follows.

2-Hydroxy-1-naphthaldehyde is dissolved in a solvent such as methanol or ethanol, and an aqueous solution of an inorganic acid salt such as manganese chloride or manganese sulfate, an organic acid salt such as manganese acetate, or a complex salt such as manganese acetylacetonate is dissolved therein. , 2-hydroxy-1-naphthaldehyde and manganese are added in a molar ratio of 1: 1 to 4: 1.
The pH of the mixture is adjusted with aqueous alkaline solution. 2-Hydroxy-1-naphthaldehyde reacts with manganese even at room temperature, but in some cases, it may be heated to such an extent that 2-hydroxy-1-naphthaldehyde and the complex are not decomposed. The precipitate formed is collected by filtration to collect the desired product.

Similarly, instead of the manganese complex, Fe, Co, Ni,
A metal complex such as Cr, Sn, Pb can be synthesized.

In the present invention, the above-mentioned metal complex of aromatic oxyaldehyde is used as a charge control agent, but may be contained anywhere in the developer composition as long as it can exhibit positive charging ability. Further, it can be used as a one-component developer or a two-component developer.

When it is used as a one-component developer, it may be added or dispersed in the binder resin of the toner, or may be attached to the surface of the toner particles.

When used as a two-component developer, it may be used as either toner particles or carrier particles.

When the metal complex of the aromatic oxyaldehydes is used, it is usually used by dispersing it in a binder resin, but the metal complex of the aromatic oxyaldehydes is not necessarily limited thereto. The toner surface may be charge-controlled by adding and mixing a complex. When it is added to the binder resin of the toner, the developer is uniformly dispersed in the toner and a developer having no variation in the charge amount between the toner particles can be obtained, which is preferable. Further, other additive components may be surface-coated in advance with the above-mentioned metal complex of aromatic oxyaldehyde and used. When used as a carrier, it is contained in a carrier coating agent or a carrier binder,
It is possible to control the charging of the toner.

The content ratio of the metal complex of the aromatic oxyaldehydes is not particularly limited, but, for example, when it is contained in the toner, it is 0.1 to
It is preferably added at a rate of 10 parts by weight.

Examples of the binder resin used for the toner in the developer composition of the present invention include styrenes such as styrene, chlorostyrene and vinyl styrene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate;
Α such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate
-Ester of methylene aliphatic monocarboxylic acid; vinyl ether such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; homopolymer or copolymer of vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone, etc. As a typical binder resin, polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene can be used. Mention may be made of maleic anhydride copolymers, polyethylene, polypropylene, polyesters, polyurethanes, epoxy resins.

Further, as the colorant of the toner, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, deupon oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, etc. Can be illustrated as a typical one.

The binder resin and the colorant are not limited to those exemplified above, and any known one can be used.

Further, the present invention can be applied to a magnetic toner containing a magnetic material and a capsule toner.

This toner has a size of about 30 μm or less, preferably 3 to 20 μm.
It is possible to use those having an average particle diameter of.

In the case where the developer composition of the present invention is a two-component developer, any known carrier can be used as the carrier. For example, iron powder, a resin-coated carrier, a carrier in which magnetic powder is dispersed in resin, and the like can be used.

If desired, various additives may be added to the developer composition of the present invention. Examples of these additives include various substances such as charge control agents, cleaning aids, fluidity promoters, and the like.

The developer composition of the present invention is used for developing an electrostatic latent image formed on a photoconductor or an electrostatic recording material. That is, selenium, zinc oxide, cadmium sulfide, inorganic photoconductive material such as amorphous silicon, a phthalocyanine pigment, a photoreceptor made of an organic photoconductive material such as a bisazo pigment, to form an electrostatic latent image electrophotographically, or The electrostatic latent image is formed on an electrostatic recording medium having a dielectric material such as polyethylene terephthalate by a needle electrode or the like, and the electrostatic latent image is formed by a developing method such as a magnetic brush method, a cascade method or a touchdown method. The developer is attached to form a toner image. This toner image is transferred to a transfer material such as paper and then fixed to form a copy, and the toner remaining on the surface of the photoconductor or the like is cleaned. As the cleaning method, various methods such as a blade method, a brush method, a web method and a roll method can be used.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.
However, the present invention is in no way limited by these examples.

Example 1 A manganese complex of 2-hydroxy-1-naphthaldehyde (hereinafter abbreviated as HNA-1) was prepared by the following method.

2-hydroxy-1-naphthaldehyde 46.4 g 1.8
Dissolved in methanol, and manganese acetate tetrahydrate 1
A solution of 8.6 g in 220 ml of water was added. After adding caustic soda solution to adjust pH to 10 and stirring at room temperature for 1 hour,
The generated insoluble matter was collected by filtration. The cake separated by filtration is washed with water and then dried under reduced pressure at 40 ° C. overnight to give HNA-13
Obtained 0.7 g. The infrared absorption spectrum of HNA-1 is shown in FIG.

Styrene-butyl acrylate copolymer (80/20) 100 parts Carbon black (Regal 330) (manufactured by Cabot) 10 parts Low molecular weight polypropylene (Viscor 660P) (manufactured by Sanyo Kasei) 5 parts HNA-1 1 part The mixture was melted and kneaded with a Banbury mixer, cooled, pulverized with a jet mill, and the pulverized product was classified with a classifier to obtain a toner having an average particle diameter of 11 μm. On the other hand, the carrier was obtained by melt-kneading the styrene-acrylic copolymer and the magnetic powder, pulverizing and classifying.

90 parts of this carrier was mixed with 10 parts of the toner to prepare a developer composition.

Example 2 A cobalt complex of 2-hydroxy-1-naphthaldehyde (hereinafter abbreviated as HNA-2) was prepared by the following method.

2-hydroxy-1-naphthaldehyde 31.1 g 2
Cobalt chloride hexahydrate 1
A solution of 1.9 g in 750 ml of water was added. A caustic soda aqueous solution was added to adjust the pH to 6, and the mixture was stirred at room temperature for 1 hour, and then the generated insoluble matter was collected by filtration. The cake separated by filtration was washed with water, and then dried under reduced pressure at 40 ° C. overnight, and HNA-2 21.
3g was obtained. The infrared absorption spectrum of HNA-2 is shown in FIG.

Styrene-butyl acrylate copolymer (80/20) 100 parts Carbon black (Regal 330) (manufactured by Cabot) 10 parts Low molecular weight polypropylene (Viscor 660P) (manufactured by Sanyo Kasei) 5 parts HNA-2 1 part The same procedure as in Example 1 was carried out to obtain a developer composition.

Example 3 In the same manner as in Example 1, a manganese complex of 3-chloro-2-hydroxynaphthaldehyde (hereinafter referred to as CHNA
(Abbreviated as -1) was synthesized. The infrared absorption spectrum of CHNA-1 is shown in FIG.

Styrene-butyl acrylate copolymer (80/20) 100 parts Carbon black (Regal 330) (manufactured by Cabot) 10 parts Low molecular weight polypropylene (Viscor 660P) (manufactured by Sanyo Kasei) 5 parts CHNA-1 1 part The same procedure as in Example 1 was carried out to obtain a developer composition.

Comparative Example Styrene-butyl acrylate copolymer (80/20) 100 parts Carbon black (Regal 330) (manufactured by Cabot) 10 parts Low molecular weight polypropylene (Viscor 660P) (manufactured by Sanyo Kasei) 5 parts Nigrosine dye (Bontron N- 03) (manufactured by Orient Chemical Co., Ltd.) 1 part The above components were treated in the same manner as in Example 1 to obtain a developer composition.

Using these developer compositions, a continuous copying test was conducted with a copying machine FX-7777 (manufactured by Fuji Xerox Co., Ltd.), and the following results were obtained.

EFFECTS OF THE INVENTION The developer composition of the present invention contains the metal complex of the aromatic oxyaldehydes, and therefore has a high rate of charge increase.
There is no variation in the triboelectric charge amount among the toner particles, a very stable positive chargeability is exhibited, and fog is not prematurely generated or contamination in the machine occurs during running. Further, the charging control function does not deteriorate with respect to environmental changes such as temperature and humidity, and stable development characteristics are exhibited.

[Brief description of drawings]

1 to 3 show Embodiments 1 to 3 of the present invention, respectively.
It is an infrared absorption spectrum figure of the compound used by.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takayoshi Aoki 1600 Takematsu, Minamiashigara City, Fuji Xerox Co., Ltd. Takematsu Office (72) Inventor Yoshihisa Matsukuma, 1 Toray Co., Ltd., Nagoya Business Office, 9 Oemachi, Minato-ku, Nagoya (72) Kenji Nakaoka No. 9 Oe-cho, Minato-ku, Nagoya City 1 Toray Co., Ltd. Nagoya Works (56) References JP-A-61-176944 (JP, A) JP-A-61-122663 (JP, A) )

Claims (1)

(57) [Claims] 1. A developer composition for an electrostatic image comprising a metal complex of an aromatic oxyaldehyde represented by the following general formula as a charge control agent. (In the formula, R is a hydrogen atom, a substituted or unsubstituted alkyl group,
Or represents a halogen atom)