JPH0445822B2 - - Google Patents

Abstract

A toner for developing electrostatic latent images containing 0.5 to 5 parts by weight of a salt forming compound represented by the formula <CHEM> wherein R1 is C1- C8 alkyl or benzyl, R2 and R3 are each C1- C18 alkyl, R4 is C1- C18 alkyl or benzyl, X is hydroxyl or amino, and Y is hydroxyl or hydrogen and is not hydrogen when X is hydroxyl, and 100 parts by weight of a resin. The invention also relates to the use of the toner for color electrophotography. The toner provides the advantage of retaining its chargeability over a long period of time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a new dry negatively charged toner for developing electrostatic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. .

[Prior Art] Originally, an electrostatic latent image can be developed and visualized by adhering toner using its electrostatic attraction, but as a developer for this electrostatic latent image,
In addition to liquid developers, powder developers are widely used.

This powder developer consists of a fine toner with an average particle size of 5 μm, which is made by dispersing a colorant, a charge control agent, a fluidizing agent, 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 made of a mixture, and a one-component developer made only of a fine toner with an average particle size of 15 μm, which is made by dispersing a colorant, a charge control agent, a fluidizing agent, a magnetic material, etc. in a natural or synthetic resin. It can be roughly divided into

A two-component developer achieves development by adhering charged toner to an electrostatic latent image through friction with a carrier, and a one-component developer uses a similar toner instead of a carrier. Toner is known to be charged by friction with a functional brush-like or plate-like friction member, and recently, toner has been developed to keep magnetic fine powder in a dispersed state and to prevent mutual friction with the magnetic fine powder. Toners that are electrically charged are known. Therefore, these developing toners maintain a positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

In order to make the toner retain this charge, it has been proposed to utilize the triboelectricity of resin, which is the main component of the toner, but this method requires that the toner has a small chargeability and a solid surface resistance value of Because of the large size, the resulting image tends to be foggy and unclear. Therefore, in order to impart the desired triboelectric charging properties to the toner, dyes, pigments, and even charge control agents that impart a charge are added to the toner, and these methods are currently in practical use in this technical field. When imparting a positive charge to the toner, there are nigrosine-based oil-soluble dyes shown in Japanese Patent Publication No. 41-2427, etc., and when imparting a negative charge, there is a dye such as nigrosine-based oil-soluble dye, etc. No. 202153, No. 43-27596, No. 44
Metal complex salts of monoazo dyes described in Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 45-42752,
Metal complexes such as Co, Cr, and Fe of salicylic acid, naphthoic acid, and dicarboxylic acids described in No. 58-41508, No. 59-7384, and No. 59-7385, etc., sulfonated copper phthalocyanine pigments, and nitro groups. , halogen-introduced styrene oligomers, chlorinated paraffins, melamine resins, etc.

However, many of the conventional charge control agents mentioned above are derived from dyes and pigments, and generally have complex structures, inconsistent properties, and poor stability, such as decomposition during hot kneading, mechanical shock, friction, and It is easy to decompose or change in quality due to changes in temperature and humidity conditions, resulting in a decrease in charge controllability. Therefore, when a toner containing these dyes and pigments as a charge control agent is used for development in a copying machine, as the number of copies increases, the charge control agent decomposes or changes in quality, causing deterioration of the toner during repeated copying operations. It can happen.

Furthermore, since it is extremely difficult to uniformly disperse these conventional charge control agents in thermoplastic resins, a fatal problem arises in that there is a difference in frictional charge between the toner particles obtained by crushing them. have. Therefore, when a conventional charge control agent is used in toner, the amount of charge generated on the surface of the toner particles is reduced between toner particles, between toner carriers, or between toner and a carrier such as a sleeve. This tends to cause problems such as development fog, toner scattering, and carrier contamination. This problem is also caused by the fact that when a large number of copies are made, the charge control agent itself adheres to the surface of the photoreceptor due to long-term use, or its presence promotes toner adhesion (occurrence of filming development). It is unlikely to cause any inconvenience in the cleaning process of the copying machine, such as adversely affecting latent image formation, causing scratches on the surface of the photoreceptor or cleaning parts such as the cleaning blade, or accelerating wear of the parts. do not have. In addition, since conventional charge control agents have strong coloring properties, they are suitable for black toner compositions, but not for color toner compositions. There is a drawback.

As described above, there are many problems with conventional charge control agents, and there is a strong demand in the technical field to solve these problems. Although there are some that are different from the previous one, the reality is that no one has yet been found that is comprehensively satisfactory for practical use.

[Problems to be Solved by the Invention] In view of the drawbacks of the conventional charge control agents mentioned above, the present invention not only can exhibit excellent charge control properties, but also
It is stable under conditions such as heating and use over time, has excellent compatibility with thermoplastic resins, has no variation in the amount of frictional charge between toner particles obtained by pulverization, and is essentially colorless or light-colored. It is an object of the present invention to provide a charge control agent that fundamentally eliminates the drawbacks of conventional charge control agents.

[Means for solving the problems] The present invention is based on the following general formula [In the formula, R ₁ , R ₂ , R ₄ and R ₅ are hydrogen, halogen, nitro group, amino group which may have a substituent, alkyl group (C ₁ to _{C 10} ), or a substituent an optional sulfamoyl group or R ₁ and R ₂ or R ₄
and R ₅ represent a group forming a ring which may have a substituent, and R ₃ and R ₆ are hydrogen, an alkyl group (C ₁ to _{C 9} ), a benzyl group, or a group having a substituent. Me represents a trivalent metal, and K represents a counter ion. However, R ₁ , R ₂ , R ₄
and R ₅ may be the same or different, and R ₃ and R ₆ may be the same or different. ] The present inventors have discovered that when these metal complexes are included in the toner, an excellent toner can be obtained. In addition to demonstrating charge controllability,
It is stable under conditions such as heating and use over time, has low hygroscopicity, has good compatibility with thermoplastic resins, and is essentially colorless or light-colored, which are extremely effective properties for achieving the above objectives. The present invention was completed by discovering that the present invention has the following properties.

[Example] Representative specific examples of the metal complex (chelate compound) represented by the general formula [] according to the present invention are shown below.

The metal complex (chelate compound) represented by the general formula [] is synthesized by a known method. That is, to obtain a symmetrical chelate, first, the aminocarboxylic acid to be coordinated or its alkali metal salt such as Na, K, etc. is dissolved or dispersed in water, or methanol, ethanol, ethyl cellosolve, dimethylform It is dissolved or dispersed in an amide or the like, and the metallizing agent is mixed in such a manner that the molar ratio of aminocarboxylic acid to metal is 2:1. Next, heat it, add a PH regulator and react,
If the chelate to be purified is a slurry, it is collected by filtration as it is; if it is a solution, it is diluted with water containing mineral acid to precipitate it, and then collected by filtration.

In the case of an asymmetric chelate, one of the aminocarboxylic acid compounds to be coordinated is dissolved or dispersed in water, or dissolved in methanol, ethanol, ethyl cellosolve, dimethylformamide, etc., and the metallizing agent is added to the aminocarboxylic acid compound. The carboxylic acid and metal are mixed in a molar ratio of 1:1. Then, the mixture is heated, and a PH regulator is added and reacted to obtain a 1:1 type complex. Next, the remaining aluminum carboxylic acid to be coordinated is added and reacted, and the resulting precipitate is filtered off. In addition, during asymmetric chelate synthesis, it is also possible to use an oxycarboxylic acid derivative instead of the aminocarboxylic acid added later, and in that case, the combination of properties of the aminocarboxylic acid complex and the oxycarboxylic acid complex may be An asymmetric chelate with succulent properties is obtained.

The chelate cake thus obtained is
If necessary, it is recovered after undergoing post-processing such as purification, drying, and pulverization.

Synthesis Example (Synthesis of Chromium Anthranilic Acid Chelate) 20.6 g of anthranilic acid was added to a solution of 6 g of caustic soda in 300 ml of water, and the mixture was heated at 80° C. to completely dissolve. Next, add 20 g of chromium chloride hexahydrate to 300 g of water.
A solution dissolved in mg was gradually added dropwise. After the addition was completed, stirring was continued at 80° C. for 2 hours, and then the mixture was allowed to cool while stirring, and then cooled to room temperature. After cooling,
Filter and wash with water until the pH of the filtrate is 6.0 to 7.0.
I did this until it became. After washing with water, it was dried at 100°C. 23 g of pale blue powder was obtained.

Examples of the central metal atom forming the chelate compound include trivalent metal atoms such as Cr, Co, and Fe.

Examples of aminocarboxylic acids represented by the general formula [] are anthranilic acid, 3-methylanthranilic acid, 3-ethylanthranilic acid, 3-n-
Butylanthranilic acid, 3-stearylanthranilic acid, 5-methylanthranilic acid, 5-ethylanthranilic acid, 5-isopropylanthranilic acid, 5-t-butylanthranilic acid, 5-laurylanthranilic acid, 3,5-dimethylanthranilic acid, 3,5-diethylanthranilic acid, 3,5
-dibutylanthranilic acid, 3-methyl-5-isopropylanthranilic acid, 3-methyl-5-t
-Butylanthranilic acid, 4-chloroanthranilic acid, 5-chloroanthranilic acid, 5-nitroanthranilic acid, 5-acetaminoanthranilic acid, 5
-Sulfamoylanthranilic acid, 3-amino-
2-naphthoic acid, 1-amino-2-naphthoic acid,
7-ethyl-3-amino-2-naphthoic acid, 7-
Heptyl-3-amino-naphthoic acid, 6-N-methylsulfamoyl-3-amino-2-naphthoic acid, 8-oxy-3-amino-2-naphthoic acid,
1-aminotetralin-2-carboxylic acid, 2-aminotetralin-3-carboxylic acid, 6-t-butyl-1-aminotetralin-2-carboxylic acid, N
-Methylanthranilic acid, 4-chloro-N-methylanthranilic acid, N-phenylanthranilic acid, N-2,3-xylylanthranilic acid, N-
Benzyl anthranilic acid, 3-N-methylamino-2-naphthoic acid, 3-N-benzyl-amino-
2-naphthoic acid, 1-aminoanthraquinone-2
-carboxylic acids and the like.

In addition to the metal complex represented by the above general formula [], the toner of the present invention is made of styrene resin, styrene-acrylic resin, etc. One type or a mixture of several types of resins such as styrene-butadiene resin, epoxy resin, polyester resin, and paraffin wax are used. Coloring agents include carbon black, lamp black, iron black, nigrosine dye, aniline black, benzidine yellow,
Hansa Yellow, Chrome Yellow, Rhodamine
Conventionally known dyes and pigments such as 6G lake, quinacridone, rose bengal, phthalocyanine dyes and pigments, ultramarine blue, triallylmethane dyes and pigments, anthraquinone dyes, monoazo and disazo dyes and pigments, etc., singly or in combination. It can be used as

Further, the toner of the present invention may contain additives other than the above-mentioned toner resin and colorant, if necessary. Examples of the additive include Teflon,
Examples include lubricants such as zinc stearate, fluidity agents such as colloidal silica, titanium oxide, and aluminum oxide, conductivity agents such as anti-caking agents, carbo black, and tin oxide, and fixing aids such as low molecular weight polyethylene. .

In the present invention, the amount of the metal complex of general formula [] added to the toner component is preferably 0.1 to 10 parts by weight, particularly 0.5 to 5 parts by weight, based on 100 parts by weight of the resin.

The toner of the present invention is mixed with a carrier to provide a two-component developer, but it can of course also be used as a one-component developer. Furthermore, it contains a magnetic material,
It can also be used as a magnetic toner.

In order to prepare the toner for developing an electrostatic image according to the present invention, a metal complex represented by the general formula [] as a charge control agent, a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, and a After thoroughly mixing magnetic materials, additives, etc. with a ball mill or other mixer according to the requirements, heating rolls,
The resins are melted and kneaded using a heat kneader such as a kneader or an extruder to disperse pigments or dyes in the mixture, which is then cooled and solidified, and then pulverized and classified to obtain an average particle size of 5 to 20 μm. of toner can be obtained. Alternatively, the toner can be obtained by dispersing the material in a resin solution and then spray drying it, or by mixing a specified material with the monomers that should constitute the resin to form an emulsified suspension and then polymerizing it. Methods such as a polymerization toner manufacturing method can be applied.

The toner of the present invention prepared by these methods can be used in all cases for development to visualize electrostatic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means. .

Specific examples of the present invention will be described below in Examples 1 to 5. In addition, in the examples, parts by weight are abbreviated as parts.

Example 1 Styrene-n-butyl acrylate (65/35 copolymer)...100 parts carbon black (manufactured by Mitsubishi Chemical Corporation, #44)
...7 parts Low polymerization degree polypropylene (manufactured by Sanyo Kasei Co., Ltd., Viscol 550P) ...3 parts Compound example (1) ...2 parts The above composition was uniformly premixed in a ball mill,
Prepare premixes. Next, the mixture was melt-kneaded at 135°C using a twin-screw extruder (manufactured by Ikegai Seisakusho Co., Ltd., PCM-30), and after cooling, it was coarsely pulverized with a vibration mill, and further finely pulverized using a Labojet (manufactured by Nippon Neumatics Co., Ltd.). . The obtained fine powder is classified to have a particle size of 5.
A black toner with a diameter of ~15 μm was obtained.

A developer was prepared by mixing 97 parts of iron powder carrier (manufactured by Nippon Tetsuko Co., Ltd., TEFV200/300) with 3 parts of the obtained toner. The initial blow-off charge amount of this developer was -28.1 μC/gr. When we measured the amount of blow-off charge after copying 10,000 sheets using a copying machine equipped with a toner recycling device, -
It was very stable at 27.5μC/gr.

Further, when the image was copied using a commercially available copying machine (Serendrum), a good image was obtained. This toner is
Even after 10,000 continuous copies were made, there was no change in image density (1.50 or more), and there was no toner fusion phenomenon (filming phenomenon) on the photoreceptor, and good images were obtained.

Example 2 Styrene-2-ethylhexyl acrylate (80/20 copolymer)...100 parts Blue pigment (copper phthalocyanine)...4 parts Blue pigment (manufactured by Orient Chemical Industry Co., Ltd., Valifast
Blue 2606)...2 parts Low polymerization degree polypropylene (manufactured by Sanyo Kasei Co., Ltd., Viscol 550P)...3 parts Compound example (2)...1.5 parts 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 -29.6 μC/gr.

When a toner image was formed using this developer using a commercially available copying machine, a clear blue image without fogging was obtained. With this toner, no deterioration in copy quality was observed even after 10,000 continuous copies were made.

Example 3 Epoxy resin (manufactured by Ciel Chemical Co., Ltd., Epicoat
1004) ...100 parts carbon black (manufactured by Mitsubishi Chemical Corporation, #44)
...6 parts Compound Example (3) ...2 parts The above formulation was treated in the same manner as in Example 1 to prepare a black 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 -25.2 μC/gr.

When this developer was copied in the same manner as in Example 1,
A clear black image with no fog was obtained. With this toner, no deterioration in copy quality was observed even after 10,000 continuous copies were made.

Example 4 Styrene-n-butyl methacrylate copolymer resin (65/35)...100 parts red (manufactured by Orient Chemical Industry Co., Ltd., Valifast
Pink 2310)...8 parts Compound Example (4)...2 parts The above formulation was treated in the same manner as in Example 1 to prepare a red 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 -22.9 μC/gr.

When this developer was copied in the same manner as in Example 1,
A clear black image with no fog was obtained. With this toner, no deterioration in copy quality was observed even after 10,000 continuous copies were made.

Example 5 Styrene-2-ethylhexyl methacrylate copolymer resin (80/20)...50 parts magnetite (manufactured by Kanto Electric Co., Ltd., KBC-100)
…45 parts carbon black (manufactured by Columbia Carbon Co., Ltd.)
RAVEN1250)...4 parts Compound example (1)...2 parts The above formulation was uniformly premixed in a ball mill,
Prepare premixes. Next, the mixture was melt-kneaded using hot rolls, cooled, and then coarsely ground using a vibrating mill, and further finely ground using a Labojet (manufactured by Nippon Neumatic Co., Ltd.). The obtained fine powder is classified to have a particle size of 5~
A one-component black toner having a diameter of 35 μm was obtained.

The blow-off charge amount of this toner is -24.7μC/g
It was r. In a test using a commercially available copier,
An image with high image density (1.40 or higher) and little fog was obtained. The toner transfer rate at that time was 90%.

[Effect of the invention] As described above, as a charge control agent, the general formula []
The toner of the present invention containing the aminocarboxylic acid chelate represented by the formula has a uniform amount of frictional charge between toner particles, and the amount of charge can be easily controlled. In addition, it is an extremely stable toner that does not change in quality during use and cause the amount of frictional charge to fluctuate or decrease. Therefore, it does not cause the above-mentioned development fog, toner scattering, and contamination of electrophotographic materials and copying machines. In addition to eliminating the problems associated with conventional toners, the toner does not suffer from toner agglomeration, clumping, and low-temperature fluidity phenomena during storage, which were major problems in the past, and can withstand long-term storage, while also improving the durability of toner images. It also has excellent abrasion, fixing and adhesion properties.

The excellent effects of such toners include charging, exposure,
When used in a repetitive transfer type copying system in which development and transfer operations are continuously repeated, the effect is even more enhanced. Furthermore, since there is little color disturbance caused by the charge control agent, when used as a color electrophotographic toner, it is possible to form color images with excellent colors.

Claims (1)

[Claims] 1. General formula [In the formula, R ₁ , R ₂ , R ₄ and R ₅ are hydrogen, halogen, nitro group, amino group which may have a substituent, alkyl group (C ₁ to _{C 10} ), or a substituent an optional sulfamoyl group or R ₁ and R ₂ or
R ₄ and R ₅ represent a group forming a ring which may have a substituent, and R ₃ and R ₆ are hydrogen, an alkyl group (C ₁ to C ₉ ), a benzyl group, or a group having a substituent. Me represents a trivalent metal, and K represents a counter ion. However, R ₁ , R ₂ , R ₄
and R ₅ may be the same or different, and R ₃ and R ₆ may be the same or different. ] A toner for developing an electrostatic image, characterized by containing a metal complex represented by the following. 2 The metal complex represented by the general formula [ ] is
The toner for developing an electrostatic image according to claim 1, wherein the amount is 0.5 to 5 parts by weight per 100 parts by weight.