JPH01147470A - Light transmitting red toner - Google Patents

Abstract

PURPOSE:To obtain a red toner superior in light transmittance by using a specified rhodanine compound as a colorant. CONSTITUTION:The colorant to be used as the colorant is one of the rhodanine derivatives represented by formula I in which R<1> is optionally substituted alkyl, such aralkyl, such aryl, or amino, and each of R<2> is H, 1-6C lower alkyl, optionally substituted aryl, or hydroxy. These rhodanine compounds are remarkably characterized by introducing the benzothiazoline group through the ethanediylidene group to the 5-position of the rhodanine ring, thus permitting the obtained toner to be improved in compatibility with a binder resin, and superior in red light transmittance, and humidity resistance, and consequently, free from humidity dependency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color toner used for developing color electrophotography, and in particular to a transparent color toner that constitutes a developed image transferred to a transparent sheet. Regarding.

[Prior art]

An overhead projector (OHP) that enlarges and projects manuscripts, etc. on a screen during meetings and research presentations.
is frequently used. In this OHP, an original image is formed on a transparent sheet, and the original image is projected onto the screen by applying light that has passed through the transparent sheet to a screen.

When using such an OHP, attempts have been made to emphasize and identify specific characters, etc. in one image using a color other than black. For this purpose, it is necessary to form a developed image using a color toner other than black on the transparent sheet.

[Problem that the invention seeks to solve]

However, the translucent color toner used in -FIQ is obtained by dispersing colored pigments in resin, so the light that enters the toner is scattered by the pigments, resulting in a loss of translucency. . Therefore, a coloring agent with excellent translucency is required.

The present invention is intended to solve the above problems,
The purpose of this is to have sufficient translucency even when transferred to a translucent sheet, so that the developed image can be transferred to a translucent sheet using a normal method and then projected onto a screen using an OHP. The purpose of the present invention is to provide a color toner that can provide vivid colors.

[Means for solving problems]

In order to solve the above problems, the toner of the present invention has the following features:
Formation (1) (R' represents substituted or unsubstituted alkyl, aralkyl, aryl, amino group, R2 is hydrogen, carbon number 1
The above object is achieved by a translucent red toner containing a rhodanine derivative represented by the following formula (indicating a lower alkyl group, a substituted or unsubstituted aryl group, or a hydroxyl group) as a coloring component.

[Effect]

The compound represented by one form CI) used in the translucent red toner of the present invention is distinctive in that it has a rhodanine ring and a compounded benzothiazoline group. Absorption of visible light is due to the formation of an intramolecular charge transfer complex in which the rhodanine ring part serves as an electron acceptor and the benzothiazoline group serves as an electron donor. That is, when the π electrons delocalized in the electron donor in the ground state are transferred to the empty orbit of the electron acceptor through the group r=C=CH-CH=J, light energy is absorbed and color is generated.

When this rhodanine compound is used as a toner colorant, a red translucent toner with excellent translucency can be obtained because of its good compatibility with the binder resin. Unlike conventional dyes, it has excellent moisture resistance, making it possible to obtain toners that are not dependent on humidity.

The present invention will be explained in detail below.

A major feature of the translucent red toner of the present invention is that the rhodanine compound represented by the above-mentioned formula (1) is used as a colorant.

In the rhodanine compound represented by the above-formation (1), examples of the alkyl group that may have one substituent among R1 include methyl, ethyl, propyl, isopropyl, butyl isobutyl, tert-butyl, pentyl, hexyl group, etc. Examples include lower alkyl groups. Examples of substituents for the alkyl group include a carboxyl group, an aldehyde group, a hydroxyl group, and a halogen atom.

Examples of aralkyl groups that may have substituents include benzyl, phenylethyl, and naphthylmethyl groups. Substituents for the aralkyl group include, in addition to the alkyl group in R1, alkoxy groups such as methoxy, ethoxy, and propoxy groups; amino groups; alkylamino groups such as dimethylamino, diethylamino, and dipropylamino groups;
Examples include halogen atoms.

Examples of the aryl group that may have a substituent include phenyl, naphthyl, anthryl, phenanthryl, fluorenyl, 1-pyrenyl, etc., and examples of the substituent of the aryl group include the substituents for the aralkyl group described above.

Examples of substituents for the amino group include the alkyl group for R1 above.

In addition, among R2, the alkyl group is methyl, ethyl,
propyl, isopropyl, butyl isobutyl, tert
-Lower alkyl groups such as butyl, pentyl, and hexyl groups are exemplified.

Examples of the aryl group include the aryl group for R1 above.

Specific examples of the rhodanine compound represented by the above-mentioned -formation (1) include those having the following structure.

(The following is a blank space) The rhodanine compound represented by the above-format CI) of the present invention can be synthesized by various methods, for example, by the following reaction formula.

(In the formula, R1 and R2 are the same as above.) That is, the compound CI of the present invention is a 3-substituted rhodanine whose form is represented by (2) above, and a 2-substituted rhodanine whose form is represented by form (3) above. -β-acetanilide It can be obtained by reacting vinylpenzole alkyl iodide in alcohol.

The binder resin used in the translucent red toner of the present invention is preferably a translucent styrene polymer, acrylic polymer, methacrylic polymer, or styrene-acrylic polymer.

Examples of unsaturated monomers used in the above-mentioned polymers include styrene, α-methylstyrene, 0-methylstyrene, p-
Styrenic monomers such as methylstyrene, p-methoxystyrene, p-chlorostyrene; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate,
Isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate,
Stearyl acrylate, cyclohexyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, cycatelaminoethyl acrylate, acrylamide, acrylonitrile, methacrylic acid, methyl methacrylate, Ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, glycidyl methacrylate, methacrylate Examples include acrylic or methacrylic monomers such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and diethylaminoethyl methacrylate. The above monomers may be used singly or in a mixture of two or more.

These polymers have a weight average molecular weight of ff130,000~
200,000. In particular, 50,000 to 15o, o-o
oO is preferable, and one or two or more kinds can be used in combination.

Further, as other toner additives, colorless toner additives that do not adversely affect the color of the toner, such as charge control agents, offset inhibitors, etc., can be added according to well-known formulations.

Examples of the charge control agent include metal soaps that are naphthenic acid, salicylic acid, octylic acid, metal salts of fatty acids and resin acids such as manganese, iron, cobalt, lead, zinc, cerium, calcium, and nickel; Examples include dyes, pyrimidine compounds, alkylsalicylic acid metal chelates, and the content thereof is preferably 0.1 to 10% by weight per toner.

The anti-offset agent may be a polyamide resin that has good compatibility with the binder resin and has transparency, such as 11-nylon, which is a polymer of ω-aminoundecanoic acid, or 12-nylon, which is a ring-opening polymer of laurolactam. - Nylon, 6,10-nylon, 6,12- which is a polymer of hexamethylene diamine, sebacic acid, and dodecasine dicarboxylic acid
It is preferable that 1 to 20 parts by weight, particularly 5 to 10 parts by weight, of nylon, a polyamide resin which is a polymer of the alkyl diamine and dimer acid, etc., is added to 100 parts by weight of the binder resin.

Next, the method for manufacturing the toner of the present invention will be briefly described.

First, binder resin, rhodanine compound, other additives, etc. are mixed, cross-dispersed using a heated kneader such as a hot roll or an extruder, and pulverized using a pulverizer such as a hammer mill or jet mill. Classify using a classifier to make the particle size uniform.

Also, is the binder resin used in a suitable solvent? It can also be produced by a spray drying method, in which the rhodanine compound and the like are dispersed in this binder resin solution, and the dispersion is spray-dried to form granules to a predetermined particle size.

[Experiment example]

Hereinafter, the present invention will be explained in more detail based on Examples.

(Example) Synthesis of 3-carboxymethyl-5-(2-(3-ethylbenzthiapurine)dimethine) rhodanine 19.1 g of 3-carboxymethyl rhodanine and 2-β
After refluxing 46.6 g of -acetanilide vinylbenzthiazole ethiodide and 12.1 g of triethylamine in ethanol for 30 minutes, the product was recrystallized from pyridine to obtain the red title compound having an absorption wavelength of 530 nm. (Yield 45%).

3-carboxymethyl-5- obtained by the above synthesis, where the upper layer is made of γ1
(24 parts by weight of 2-(3-ethylbenzthiazoline) dimethine, 10 parts by weight of polystyrene resin as a binder resin)
0 parts by weight and 2 parts by weight of Bontron E-84 (manufactured by Orient Chemical Co., Ltd.) as a charge control agent were mixed uniformly using a Henschel mixer FM20B (manufactured by Mitsui Miike Kakoki Co., Ltd.), and then transferred to a twin-screw extruder PCM. -30 (manufactured by Ikegai Tekko Co., Ltd.), and was melt-kneaded and solidified with cold air. Next, the coarsely pulverized product was coarsely pulverized using a feather mill (manufactured by Wire Micron Co., Ltd.), and the coarsely pulverized product was finely pulverized using a jet mill ID5-5 model (manufactured by Nippon Uniumatic Co., Ltd.), and an Alpine classifier 132MPL (manufactured by Yasuo Denki Co., Ltd.) was used. ) to remove fine powder with a particle size of 5 μm or less to obtain a red toner with an average particle size of 11 μm.

To 100 parts by weight of the above red toner, 065 parts by weight of Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.), which is a hydrophobic silica, was added as a fluidity imparting agent, and after surface treatment using a Henschel mixer, aggregates were removed using a vibrating sieve. did. Then, the above toner and ferrite carrier (average particle size 70 μm, manufactured by Nippon Tetsuko Co., Ltd.) were mixed using a Nauta mixer.
A developer having a toner concentration of 465% by weight was prepared.

(Comparative Example) In place of 3-carboxymethyl-5-(2-(3-ethylbenzthiazoline)dimethine)rhodanine in Example,
Eisens Viron Red GEH (manufactured by Hodogaya Chemical Co., Ltd.) 1.
A red toner and developer were prepared in the same manner as in the example using 5 parts by weight.

(Evaluation) Using the toners of Examples and Comparative Examples produced as described above, ordinary color electrophotographic copy @ (DC manufactured by Sanda Kogyo Co., Ltd.) was used.
-2055), and the developed image was transferred and fixed onto a translucent sheet (polyethylene terephthalate).

When the images were projected onto a white projection surface using an OHP, the images according to the examples had more vivid colors than the images according to the comparative examples.

〔Effect of the invention〕

According to the present invention, as described above, by using a rhodanine compound as a colorant, a red toner with excellent translucency can be obtained, and a clear color image can be projected on an OHP screen. becomes.

Claims (1)

[Claims] The following general formula▲ includes numerical formulas, chemical formulas, tables, etc.▼ (R^1 represents substituted or unsubstituted alkyl, aralkyl, aryl, or amino group, and R^2 represents hydrogen or the number of carbon atoms A translucent red toner containing, as a coloring component, a rhodanine derivative represented by 1 to 6 lower alkyl groups, substituted or unsubstituted aryl groups, or hydroxyl groups.