JPH02102269A - Nigrosine compound, production of halogenated nigrosine compound, production of nigrosine compound and electrostatic image developing toner containing same - Google Patents

Abstract

PURPOSE:To obtain a nigrosine compound improved in dispersibility in a toner resin, compatibility with this resin and heat resistance and being useful as a positive charge-donating charge controller having high frictional charging characteristics by reacting a specified halogenated nigrosine compound with an amine compound. CONSTITUTION:A nigrosine dye (i) (e.g., C.I. Solvent Black 7) ls halogenated with a halogenating agent (ii) (e.g., Br) in a water-soluble organic solvent (iii) (e.g., dimethyl sulfoxide), component (iii) is removed from the product, and the product is treated with an alkali (iv) (e.g., NaOH) to obtain a halogenated nigrosine compound (a) of formula I (wherein D is a residue of component (i); X is a halogen atom) and a is 2-9). Component (a) is reacted with at least one active hydrogen-containing amine compound (b) selected from among an aliphatic amine, a hydroxyalkylamine and an alkoxyalkylamine to obtain a nigrosine compound of formula II (wherein Y is a residue of component (b), n and m are each 1-8, and n+m=2-9).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a nigrosine compound particularly excellent in heat resistance and charging characteristics, a method for producing the same, and a halogenated nigrosine compound as an intermediate for the nigrosine compound. Regarding the manufacturing method of nigrosine-based compound, and the electrostatic image developing toner containing the nigrosine-based compound, more specifically, it is not a single component having one chemical structure, but a mixture of multiple types of compounds having azine and oxazine rings. The invention relates to a nigrosine-based compound having at least a halogen atom as a substituent atom, a method for producing the same, and a method for producing an intermediate thereof. Furthermore, the present invention relates to a toner for developing electrostatic images characterized by containing the compound as a charge control agent.

(Prior art) Nigrosine dyes (C,1, Solvent Black 5, C,1, Solvent Black 7, or C,1, Solvent Blue) have traditionally been used as dyes soluble in organic solvents to color synthetic resins. It is widely used in agents, printing inks, felt pen inks, ballpoint pen inks, etc.

In recent years, nigrosine dyes have also been used as charge control agents for toners for electrophotographic development, taking advantage of their triboelectric properties.

For example, nigrosine base (C, 1, Solvent Black 7) obtained by alkali treatment of nigrosine hydrochloride
) and fatty acid-modified nigrosine dyes obtained by salt-forming this nigrosine base with higher fatty acids such as stearic acid, oleic acid, and maleic acid.

However, the above-mentioned nigrosine-based dyes generally have poor heat resistance, so if these nigrosine-based dyes are used as charge control agents, they are likely to undergo thermal decomposition during the toner manufacturing process (melt-kneading process), making them stable. There have been problems such as the inability to produce toner having triboelectric charging characteristics.

Conventionally, as a nigrosine compound, for example, JP-A-59
JP-A-68374 discloses an alkyl-substituted nigrosine compound obtained by the reaction of a nigrosine dye and an alkyl halide, and JP-A-63-4245 discloses insulin (C,1, solvent), which is homologous to the nigrosine dye. A blue toner for electrophotography containing tetrafluoroboric acid or an organic acid as an anion is disclosed.

However, these improved nigrosine dyes were developed to improve the dispersibility and compatibility with the binder resin of toners for electrostatic copying, or to be used in oil-based inks, and are not suitable as charge control agents. It has not yet been possible to impart the required high triboelectric charging characteristics to a developing toner.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems, and its purpose is to provide excellent dispersibility and compatibility with toner resins, and to It is an object of the present invention to provide a nigrosine-based compound useful as a positive charge-imparting charge control agent that has excellent heat resistance and high triboelectric charging properties, and a method for producing the same. Another object of the present invention is to provide a method for producing a halogenated nigrosine compound as an intermediate for the nigrosine compound, and an electrostatic image toner containing the nigrosine compound.

(Means for Solving the Problems) The nigrosine compound of the present invention has the following general formula [wherein D
represents a nigrosine dye residue; m represents a number from 1 to 8, and n+m ranges from 2 to 9. The above objective is achieved by this.

Further, the method for producing a halogenated nigrosine compound of the present invention is characterized by halogenating a nigrosine dye in a water-soluble organic solvent, removing the solvent, and then treating with an alkali, expressed by the following general formula (II). This is expressed as follows, thereby achieving the above objective.

D-(X).

(n) [Wherein, D represents a nigrosine dye residue, X represents a halogen atom, and a represents a number from 2 to 9. ] The halogen is preferably bromine.

Further, the method for producing a nigrosine compound of the present invention includes: the halogenated nigrosine compound; an amine compound having at least one active hydrogen selected from the group consisting of aliphatic amines, hydroxyalkylamines, and alkoxyalkylamines; The above purpose is achieved by reacting the above objects. Further, the toner for developing electrostatic images of the present invention is characterized by containing the above nigrosine compound as a charge control agent, thereby achieving the above object.

The present invention will be explained in detail below.

In the compound represented by the general formula CI), the hydrogen atoms in the skeleton of the nigrosine dye residue are substituted with halogen atoms, and some of the halogen atoms react with the amine compound to form the amine residue Y. This is a compound replaced by .

Examples of the halogen atom X include bromine, chlorine, and iodine, with bromine being particularly preferred.

Originally, nigrosine dyes are not clearly defined compounds, but are defined as compounds having the following structure.
(The Chemistry of 5ynthet
ic Dye and Pigment (1955)
p. 243).

C6■s C6H5 6H5 Therefore, the nigrosine dye residue means a compound having an azine ring or an oxazine ring, including the above-mentioned compounds, and excludes similar insulin.

Among the above amine residues Y, the aliphatic amines include, for example, aliphatic amines having 3 to 12 carbon atoms (e.g., n-butylamine, isobutylamine, dibutylamine, n-hexylamine, cyclohexylamine, 2-ethylhexylamine). , n-dodecylamine), and the like. Examples of the hydroxyalkylamine include ethanolamine, jetanolamine, propatoolamine, isoproptoolamine, and the like. Examples of the alkoxyalkylamine include 3-methoxy-1-propylamine, 3-ethoxy-1-propylamine, 3-butoxy-1-propylamine, 3-octoxy-1-propylamine, 3-(2ethylhexyloxy) )-1-
propylamine), etc. One or more selected from these may be substituted with the skeleton of the nigrosine dye residue.

Next, a method for producing a halogenated nigrosine compound of the present invention will be explained.

First, a nigrosine dye is halogenated in a water-soluble organic solvent. Here, as the nigrosine dye, generally known dyes can be used. For example, nigrosine hydrochloride (C
Examples include Nigrosine base (C, 1, Solvent Black 7) obtained by alkali treatment of Solvent Black 5), which is obtained by dissolving or dispersing this nigrosine dye in a water-soluble organic solvent, , halogenating using a halogenating agent such as iodine. As the water-soluble organic solvent, dimethyl sulfoxide, dimethyl formamide, or alcohols can be used.

The halogenation reaction in the present invention is a cationoid substitution with a halogen cation, and is a direct substitution reaction in which a hydrogen atom of a 6-membered carbon ring adjacent to an azine or oxazine ring of a skeleton such as a nigrosine dye is substituted. The number of halogen atoms introduced into the six-membered carbon ring varies depending on the reaction conditions, but is considered to be 1 to 9, preferably 2 to 4. Next, the reaction solution is poured into water with stirring, treated with an alkali, filtered and washed with water to obtain a halogenated nigrosine compound.

This halogenated nigrosine compound has the following general formula (I
I).

D-(X), -(II) [wherein,
D represents a nigrosine dye residue, X represents a halogen atom, and a represents a number from 2 to 9. ] Next, a method for synthesizing the nigrosine compound of the present invention will be explained.

(2) The halogenated nigrosine compound obtained above is dissolved or dispersed in a water-soluble organic solvent (for example, N-methylpyrrolidone, dimethylsulfoxide, dimethylformamide).

(2) Next, an amine compound having active hydrogen (for example, at least one selected from aliphatic amines, hydroxyalkylamines, and alkoxyalkylamines) and anhydrous alkali metal carbonate are added to the above solvent.
React at ~160°C for 8-10 hours.

(2) After cooling the reaction solution to 20-35°C, the reaction solution is poured into water with stirring to precipitate the reactant.

■Next, add an acid (e.g. acetic acid) to the resulting reactant slurry.
is added to adjust the pH to 3 to 5, filtered, and washed with water.

■Then, the obtained wet reactant was dispersed again in water and the pH was adjusted to 7-8 with dilute caustic soda solution, and then the pH was adjusted to 2-8.
After stirring for 3 hours, filter, wash with water, and dry.

The nigrosine compound of the present invention thus obtained is a mixture in which some of the halogen atoms of the halogenated nigrosine compound are replaced with amine residues Y through a substitution reaction with an amine compound.

Therefore, the number n of halogen atoms is 1-8, preferably 1-4. The number m of amine residues Y is 1-8, preferably 3-1.

The nigrosine compound thus obtained has excellent triboelectric charging properties, excellent dispersibility and compatibility with various resins, and excellent heat resistance, so it can be used as a developing toner in electrostatic photography. It can be suitably used as a charge control agent. Further, the nigrosine-based compound and the halogenated nigrosine-based compound of the present invention can be suitably used as a coloring agent for polyamide having excellent heat resistance.

Next, a method for manufacturing a black toner used in a dry development method using the nigrosine compound of the present invention as a charge control agent will be explained. - Acrylic copolymer, epoxy resin) 100 parts by weight (
(hereinafter referred to as part) and colorants such as dyes and pigments (for example,
1 to 10 parts of carbon black, iron oxide pigment, azo metal-containing complex dye) and 1 to 5 parts of a charge control agent (nigrosine compound obtained above) are prepared in a mixing machine such as a ball mill or a blender. Mix and prepare premix. In order to improve the quality of the toner, additives such as magnetic substances, internal lubricants, and image peeling preventive agents may be added as necessary.

Next, the toner is melt-kneaded using a hot roll, an extruder, or the like at a temperature at which the toner melts, for example, 130 to 180°C. After cooling, this kneaded material is coarsely ground using a hammer mill, pulverizer, etc., and then finely ground using an air jet mill. Thereafter, classification is performed to obtain a black toner having a particle size of preferably 5 to 20 μm.

(Example) Below, the present invention will be described in more detail with reference to Examples.

<Manufacture of brominated nigrosine compounds> Nigrosine base (C, 1, Solvent Black 7;
Manufactured by Orient Kagaku Kogyo Co., Ltd., nigrosine base Eχ) 1
00 g of dimethyl sulfoxide (water-soluble organic solvent)
After stirring to dissolve or disperse at room temperature, 54 g of bromine (halogenating agent) was added dropwise over 60 minutes while maintaining the temperature of the solution at 35 to 40°C. Thereafter, the liquid temperature was raised to 100°C over 30 minutes, and then stirred at 100°C for 120 minutes. The resulting reactant was then injected as a trickle into 100IR1 of water to precipitate and disperse the product. The pn of this dispersion is 1.7
Met. Next, this dispersion was neutralized with a caustic soda solution, filtered, and then the product was thoroughly washed with water. Next, the product was dried at 80°C to obtain 138g of black powder (Compound Example 1). Table 1 shows the results of elemental analysis of this compound.

The water-soluble organic solvent used in Example 1 was changed to the solvent shown in Table 2, and the amount of bromine used was changed to the amount shown in Table 2.
Black powder was obtained in the same manner as in Example 1 (Compound Examples 2 to 4)
). The yields of these compounds are shown in Table 2.

(Left below) <Manufacture of nigrosine compound> Charcoal 1 To 100 g of N-methylpyrrolidone, 28 g of the compound obtained in Example 1 and 3-(2-ethylhexyloxy)-
Add 20 g of 1-propylamine (manufactured by Koei Chemical Industry Co., Ltd.) and 3 g of finely ground anhydrous potassium carbonate, and heat at 150°C.
After stirring for 8 hours, the mixture was allowed to cool to room temperature. The reactant is mixed with 1 part of water.
The reaction product was precipitated by adding 500 mR with stirring. Next, acetic acid was added to adjust the PL to +4.0, and after stirring for 2 hours, it was filtered and thoroughly washed with water. Next, this wet reaction product was added again to 1500 mj! Dispersed in water, adjusted to pH 7.5 with dilute caustic soda solution, stirred for 2 hours, filtered and washed with water, and then dried to obtain a black powder of 32.5
g (Compound Example 5) was obtained.

Table 1 shows the results of elemental analysis of this compound.

25 g of the compound obtained in Example 1, 9 g of jetanolamine (manufactured by Koei Chemical Industry Co., Ltd.), and 4.3 g of finely ground anhydrous potassium carbonate were added to 100 g of dimethylformamide and heated at 145'C for 8 hours. After stirring, the mixture was allowed to cool to room temperature. The obtained reaction product was poured into 1000 d of water with stirring to precipitate a reaction product, which was filtered and thoroughly washed with water.

Next, this wet reaction product was again dispersed in water at 10100 O, adjusted to pt (7,5) with dilute caustic soda solution,
After stirring for 2 hours, the mixture was filtered, washed with water, and then dried to obtain 26.4 g of black powder (Compound Example 6). Table 1 shows the results of elemental analysis of this compound.

Further, Table 3 shows the numbers a and n of substituted bromines and the number m of amine residues Y in each compound, which were calculated from the results of the above elemental analysis. (However, the average amount of nigrosine base Eχ was set to 600) In addition, FIG. 1 shows the results of differential thermal analysis of the brominated nigrosine compound obtained in Example 1, and FIG. The results of differential thermal analysis of the nigrosine-based compound obtained in are shown.

FIG. 3 shows the results of differential thermal analysis of the starting material Nigrosine Base EX (C,1, Solvent Black 7) used in Examples 1 to 4. From these results, the comparative material Nigrosine Base EX shows severe thermal abnormalities, whereas the compound of the present invention shows only slight thermal decomposition or phase change at 200 to 440°C. This is confirmed.

Moreover, the infrared absorption spectrum of the nigrosine-based compound obtained in Example 5 is shown in the 4th article, and the infrared absorption spectrum of Nigrosine Base EX (C, 1, Solvent Brass Tsuk 7) is shown in FIG.

(Leaving space below) Table 3-1 Table 3-2 In the table, X: halogen atom, Y: amine compound residue, 00P: 3-(2-ethylhexyloxy)-1 propylamine, IIE8 diethanolamine. represent.

a and n indicate the number of substituted atoms, and m indicates the number of substituents.

<Examples and comparative examples of electrostatic image developing positive toner containing the compound of the present invention as a charge control agent> Example 1 Styrene-acrylic copolymer (manufactured by Mitsubishi Chemical Corporation, Hymer MSB600) 100 parts, carbon black ( (manufactured by Mitsubishi Kasei Corporation) and 1 part of a charge control agent (nigrosine compound obtained in Example 5) were uniformly premixed using a high-speed mixer.

Next, this material was melt-kneaded using an extruder, cooled, and coarsely ground using a vibration mill. The obtained coarsely pulverized product was pulverized using an air jet mill equipped with a classifier to obtain a black toner having a particle size of 10 to 20 μm.

A developer was prepared by mixing 1 part of the obtained toner with 50 parts of an iron powder carrier (manufactured by Nippon Tetsuko Co., Ltd., TEFV200/300).

A toner was prepared in the same manner as in Example 7, except that the amount of the charge control agent used in Example 7 was changed to 0.1 part.

Actual U A toner was prepared in the same manner as in Example 7, except that the amount of the charge control agent used in Example 7 was changed to 0.1 part.

A toner was prepared in the same manner as in Example 7, except that the charge control agent was replaced with nigrosine base EX, which is the starting material of the present invention.

A toner was prepared in the same manner as in Example 7, except that the charge control agent was replaced with nigrosine base EX, which is the starting material of the present invention, and the amount used was 0.1 part.

The main charge control agent was higher fatty acid-modified nigrosine (Bontron N).
A toner was prepared in the same manner as in Example 7, except that the toner was replaced with (-02; manufactured by Orient Kagaku Kogyo Co., Ltd.).

Next, Table 4 shows the results of measuring the amount of charge of the developing toners obtained in Examples 7 to 9 and Comparative Examples 1 to 3 by a plow-off method.

From the results in Table 4, it was confirmed that by using a nigrosine compound as a charge control agent, the charging characteristics were excellent even when a small amount was used.

(Effects of the Invention) As described above, the compound of the present invention improves heat resistance by introducing a halogen atom into the nigrosine dye skeleton, and improves dispersibility in toner resin by introducing an amine residue. A positive charge-imparting charge control agent can be obtained which can improve compatibility, has unprecedented heat resistance, and has high triboelectric charging properties. Therefore, an electrostatic image developing toner containing this charge control agent has a fast charge build-up speed and can provide a charge amount that does not change over time or with various environmental changes (mainly humidity).

Furthermore, according to the method for producing nigrosine compounds and halogenated nigrosine compounds of the present invention, each compound having the above-mentioned performance can be produced relatively easily.

Figure 2 is a diagram showing differential thermal analysis of the compound of Example 5,
Figure 3 shows the starting material nigrosine base E used in Example 1.
FIG. 4 shows the infrared absorption spectrum of the compound of Example 5, but FIG. 5 shows the infrared absorption spectrum of nigrosine base EX.

that's all

Claims (1)

[Claims] 1. The following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] [In the formula, D represents a nigrosine dye residue, X represents a halogen atom, and Y represents Represents at least one residue selected from the group consisting of aliphatic amines, hydroxyalkylamines, and alkoxyalkylamines, where n is 1 to 8, m
represents a number from 1 to 8, and n+m ranges from 2 to 9. ] A nigrosine compound represented by. 2. A method for producing a halogenated nigrosine compound represented by the following general formula [II], which comprises halogenating a nigrosine dye in a water-soluble organic solvent, removing the solvent, and then treating with an alkali. D-(X)_a [II] [Wherein, D represents a nigrosine dye residue, X represents a halogen atom, and a represents a number from 2 to 9. 3. The method for producing a halogenated nigrosine compound according to claim 2, wherein the halogen is bromine. 4. A claim in which the halogenated nigrosine compound according to claim 2 or 3 is reacted with an amine compound having at least one type of active hydrogen selected from the group consisting of aliphatic amines, hydroxyalkylamines, and alkoxyalkylamines. 1. A method for producing a nigrosine compound according to 1. 5. A toner for developing an electrostatic image, comprising the nigrosine compound according to claim 1 as a charge control agent.