JPS5988745A - Toner for electrophotography - Google Patents

Abstract

PURPOSE:To obtain a toner which has negative electrostatic chargeability, has good compatibility to a binder resin, obviates uneven electrostatic charge, dropout, ground contamination and is suitable for high speed continuous copying by incorporating a specific asymmetric metallic complex compd. as an electrostatic charge control agent. CONSTITUTION:A toner contg. a colorless compd. expressed by the formula I [R1 is H, C1-18 alkyl, A is a group expressed by formulas II-VI, Z is H, halogen, NO2, C1-8 alkyl or alkenyl, and in the formulas II, VIII, n is 1-3, R2 is H, C1-18 alkyl or alkenyl, X, X' are -O-, -NH-, -NR'-(R' is C1-4 alkyl), M is Cr or Co, B is H, Na, K, NH4, aliphat. and alicyclic ammonium, m is 1-4] as an electrostatic charge control agent together with a binder resin and a coloring agent such as dye and pigment is prepd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing electrostatic latent images in electrophotography, electrostatic recording, and the like.

Electrophotography is a photoconductive film composed of photoconductive substances, etc.
A common method is to form a latent image on the body, develop it with a powder developer to make it visible, and then fix it on paper using heat, a solvent, or in some cases pressure. As a developer for such electrophotography, a mixture of a fine particle powder called developer powder or toner, which is made of a resin and a colorant, and a carrier, such as minute glass beads or iron powder, is used.

In this case, a developer using extremely fine ferrite or magnetite as a carrier is called a one-component developer, and can be distinguished from the former.

The present invention relates to developer powder called toner of these developers. The light guide layer can be positively or negatively charged so that exposure under the original produces a positive or negative electrostatic latent image. Therefore, the negative electrostatic charge creates a positive band 1 on the latent image.

A positive image is produced. However, when the electrostatic latent image is developed with negatively charged developer powder, the black and white tones are reversed and a negative image of the original, that is, a positive negative image is obtained. As described above, there are two types of developer powder for electrophotography: positively charged developer powder and negatively charged developer powder.

31 Among these, the present invention relates to negatively charged developer powder.

Generally, developer powder is fine particles made of synthetic resin mixed with colorants such as dyes and pigments. Conventionally, in developing powders, it has not been possible to obtain desirable chargeability with the resin used alone, and charge control agents such as dyes, pigments, or metal complex compounds have been used to provide appropriate chargeability with this resin pressure. Ta.

Currently known charge control agents that impart a positive charge to toner include nigrosine dyes, and those that impart a negative charge include Japanese Patent Publication No. 41-6597 @ Japanese Patent Publication No. 45-27596 , Japanese Patent Publication No. 51-29827, etc. All of these materials are colored substances and are limited to developers having the same color tone as the dye, and their application is extremely difficult, especially in the case of color copying.

Next, as a colorless control agent, Japanese Patent Publication No. 55-42752
Publications, Japanese Unexamined Patent Publication No. 57-104940, etc. can be mentioned. However, in all cases of 4-, the compatibility with the various resins used in the toner is still not sufficient, resulting in uneven charging, resulting in a lack of uniformity in the resulting toner, and when developed. This may cause white spots and background stains. Furthermore, it has the disadvantage of lacking charging stability even in high-speed and continuous copying.

The present inventors have completed the present invention as a result of repeated studies on colorless metal complex compounds that do not have these drawbacks. That is,
In the following general formula f, R+1. hydrogen atom, C2-I8 alkyl group, A atom, halogen atom, nitro atom, C8-CI8
an alkyl or alkenyl group, n represents an integer of 1 to 6; ) and C Yude Kitsune, @Seri Demi.

Table 2 or alkenyl group. ). X.

X' represents 10-, -S-, Y and Y' represent 10-
.

represents. ), and X and X' and Y and Y' may be the same or different, respectively. M represents a chloro or bart atom, Bo represents hydrogen, sodium, potassium, ammonium, aliphatic ammonium or alicyclic ammonium ion, and m represents an integer of 1 to 4.

) This is an electrophotographic toner characterized by containing an asymmetric metal complex compound represented by: The colorless control agent of the present invention has extremely good compatibility with various resins,
Toners containing these compounds can provide extremely clear and stable copied images not only in initial copies but also in high-speed and continuous copying.

The asymmetric metal complex compound of formula (1) used in the developing powder of the present invention can be synthesized by a conventional method.

That is, the following compound (wherein A, X and Y are as defined above):
in water or a solvent such as alcohol or ketones,
Heat treatment with a chromium or cobalt imparting agent in an equivalent molar amount to the above compound, and then heat treatment with addition of the following compound (wherein R1, m, X' and Y' are as previously defined). An asymmetric 2:1 type metal complex is formed by this, and the counterion can be changed appropriately depending on the pH at the time of extraction, the type of alkali, and the type of amine, and the asymmetric 2:1 type metal complex shown in the old general formula (1) can be changed. type metal complex compounds can be obtained in high yield.

The toner of the present invention contains a binding substance and a coloring substance in addition to the metal complex compound, and examples of the binding substance that can be suitably used in the toner of the present invention include styrene and polystyrene such as polystyrene and polyvinyltoluene. Monomers of substituted hyaluronic acid, styrene-substituted styrene i! Coalescence, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-acrylonidonyl copolymer, polyvinyl chloride, polyethylene, silicone resin, polyester, polyurethane, polyamide, epoxy resin , modified rosin, phenolic resin, etc. can be used alone or in combination.

Examples of coloring substances include C,1, Pigment Yellow 12, C,I, and Solvent Yellow 16, C,I.

Disbirds Yellow 53, C, 1, Pigment Red 122, C', 1. Solvent Red 19, C,1, Pigment Yellow 15, C,1, Pigment Black 1
, C, 1, Solvent Black 3. C, I, solvent bluff 22, carbon blank, etc. can be used. Another feature of the present invention is that by using it in combination with a colored dye having a known charge control agent, the drawback of lack of long-term stability of known charge control agents can be significantly improved.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Synthesis of asymmetric metal complex compound 1 8 parts of 2-hydroxy-3-naphthoic acid 1a, 200 parts of water and 153 parts of chromium chloride were added and heated at 95 to 100°C.
After heating and stirring for an hour, add 10 parts of urea and 6 parts of salicylic acid.
．． After adding 9 parts and stirring at 95-100℃ for 1 hour,
Add IJium aqueous solution to adjust the pH to 9-10.
Upon cooling, a pale greenish-white precipitate was precipitated, which was filtered, washed with water, and dried to obtain 40 parts of an asymmetric 2:1 type RI-ROM complex compound represented by the following formula: 8-.

Manufacture of toner! 100 parts of styrene-acrylic copolymer resin, 6 parts of carbon black (Regal 300R, manufactured by Kabotsu Co., Ltd.) and []
1 part of the asymmetric chromium complex compound synthesized in Section f was added, mixed thoroughly, heated and melted, cooled, and ground in a ball mill to obtain a negatively charged fine developer powder.

Next, apply this developing powder to a powder with a weight ratio of 5:10n and a diameter of 100 to 1
A developer was obtained by mixing with 50μ iron powder.

Next, an electrostatic latent image of the tail pressure is formed on the selenium photosensitive plate charged by corona discharge (+5000V), and this positive image is transferred to paper and fixed by heat to create a clear image with no fog and clear halftones. An image was obtained, and even after the 70,000th continuous copy (running), there was almost no change in the development characteristics of the toner, and a good copy that was the same as the initial image was obtained.

In addition, the amount of charge on the toner was measured using the plow-off method, and the initial charge
The charge amount of the toner at the 70,000th sheet of running is -20.1μC/II, which is almost the same as the initial value, and the charge distribution is -2
At 0.0--20.3 pc/I, y was uniform, and all were extremely excellent toners.

Example 2 The following asymmetric metal complex compound was synthesized according to Example 1.

The composition of 100 parts of epoxy resin, 537 parts of C, I, Deathbirds Yellow' and 2 parts of the above asymmetric chromium complex compound was processed in the same manner as in Example 1 to obtain a developing powder, and further mixed with an iron carrier to form a developer. was prepared. When copying was carried out in the same manner as in Example 1 using this yellow developer, clear images without fogging were obtained.
The millionth image remained clear and clear. In addition, the initial band W wound'' of this toner is -12.5 μc/f, and the toner charge at the 70,000th sheet is -12.8 μC/I, which is almost the same as the initial value, and the charge distribution is -12.8 μc/I. The toner had a uniformity of 12.5 to -12.7 pc/f, and was extremely excellent as a toner.

Examples 5 to 8 Toners were obtained in the same manner as in Example 1 using the developer composition shown in the following table. The image properties and charging patents of these toners are also summarized in the table.

Claims (1)

[Scope of Claims] The following general formula (where RI is a hydrogen atom, CI~18 alkyl group, A atom, halogen atom, nitro atom, ct"" CI
The alkyl or alkenyl group of B, n represents an integer of 1 to 3 as shown in Table 1 (2 represents a kyl or alkenyl group). X. X' represents -o+, -8-, Y and Y' represent 10+
. represents. ), and X and X' and Y and Y' may be the same or different, respectively. M represents a chloro or =bart atom, B■ represents hydrogen, sodium,
Potassium, ammonium, aliphatic ammonium and alicyclic ammonium ions are represented, and m represents an integer of 1 to 4. ) An electrophotographic toner comprising an asymmetric metal complex compound represented by: