JPH01147467A - Light transmitting orange toner - Google Patents

Abstract

PURPOSE:To obtain an orange 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> and R<3> is H, alkyl, or optionally substituted aryl, optionally same or different from each other. These rhodanine compounds are characterized by introducing said benzylidene derivative 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 orange 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 particularly to a transparent color toner constituting 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 two images 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 most used translucent color toner is
Since it is obtained by dispersing colored pigments in a resin, 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 a substituted or unsubstituted alkyl, aralkyl, aryl, or amino group, and R2 and R3 are the same or different and represent hydrogen, an alkyl group, or a substituted or unsubstituted aryl group) The above object is achieved by a translucent orange toner containing the represented rhodanine derivative as a coloring component.

[Effect]

The compound represented by the general formula (r) used in the translucent orange toner of the present invention is characterized in that it has a rhodanine ring and a benzylidene group introduced at the 5-position of the rhodanine ring. 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 benzylidene part 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-J, light energy is absorbed and color is generated. In particular, by introducing an electron-donating amino group into the rose position of the benzylidene group, the electron-donating property of the benzylidene group is strengthened, and light absorption is increased in the visible light range (approximately 47
2 nm).

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

The present invention will be explained in detail below.

A major feature of the translucent orange 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 (I), examples of the alkyl group that may have a substituent among R1 include lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl isobutyl, tert-butyl, pentyl, and hexyl groups. Examples include 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 in the aralkyl group described above.

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

Furthermore, among RZ and R3, alkyl groups include methyl, ethyl, propyl, isopropyl, butylisobutyl, t
Examples include lower alkyl groups such as ert-butyl, pentyl, and hexyl groups. Note that as the number of carbon atoms in the alkyl group increases, the electron donating property of the amino group weakens, so the absorption wavelength of the produced rhodanine derivative tends to become shorter.

Therefore, in order to absorb light in the visible range, the amino group must be unsubstituted or substituted with methyl, ethyl, propyl,
Preferably, the isopropyl group is used.

Examples of the aryol group include the aryol group in R' above. Note that R2 and R3 may be the same or different from each other.

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

Among the rhodanine taHL bodies described above, 3-carboxymethyl-5-(p-diethylaminobenzylidene) rhodanine and 3-phenyl-5-(p-diethylaminobenzylidene) rhodanine are particularly preferably represented by the above-formation (1) of the present invention. The rhodanine compound can be synthesized by various methods, for example, according to the reaction formula below.

(In the formula, R', R", and R" are the same as above.) That is, the compound of the present invention (13 is a 3-substituted rhodanine represented by the above-formation (2)) and a 3-substituted rhodanine represented by the above-formation (3). It can be obtained by reacting equimolar amounts of p-aminobenzaldehyde, p-dialkylaminobenzaldehyde, or p-diethylaminobenzaldehyde.

The binder resin used in the translucent orange 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. o.

O~200,000, especially 50,000~15o, o
ooO is preferable, and one type or a mixture of two or more types can be used.

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 IO parts by weight, of nylon, a polyamide resin which is a polymer of the above-mentioned 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.

It can also be produced by a spray drying method in which the binder resin is dissolved in a suitable solvent, the rhodanine compound, etc. is dispersed in the binder resin solution, and the dispersion is spray-dried to form granules to a predetermined particle size. be able to.

[Experiment example]

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

(Example) Synthesis of rhodanine conductor 3-carboxymethyl-5-(p-diethylaminobenzylidene) rhodanine 19.1 g of 3-carboxymethyl rhodanine and 17.7 g of p-diethylaminobenzaldehyde were mixed in DMF.
The reaction was carried out at 100°C. After 3 hours, the reaction solution was added to water, and the resulting precipitate was washed with water and then recrystallized with acetone to obtain an orange title compound having an absorption wavelength of 472 nm. (Yield 87%).

3-carboxymethyl-5- obtained from the above synthesis
4 parts by weight of (p-diethylaminobenzylidene) rhodanine, 100 parts by weight of polystyrene resin as a binder resin, and 2 parts by weight of Bontron E-84 (manufactured by Orient Chemical Co., Ltd.) as a charge control agent were mixed, and a Henschel mixer FM20B was prepared.
(manufactured by Mitsui Miike Kakoki Co., Ltd.) and then melt-kneaded using a twin-screw extruder PCM-30 (manufactured by Ikegai Tekko Co., Ltd.) and solidified with cold air. Next, it is coarsely crushed using a feather mill (manufactured by Wire Micron Co., Ltd.), and the coarsely crushed product is passed through a jet mill ID.
Finely pulverize using type 5-5 (manufactured by Nippon Pneumatic Co., Ltd.),
Albine classification [132MPL (manufactured by Yasuyo Denki Co., Ltd.) with particle size of 5
By removing fine powder less than μm, the average particle size is 11 μm.
An orange toner of m was obtained.

To 100 parts by weight of the above orange toner, 0.5 parts by weight of Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.), which is a hydrophobic silica as a fluidity imparting agent, was added, and after surface treatment with a Henschel mixer, the aggregates were removed using a vibrating sieve. was removed. 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 4.5% by weight was prepared.

(Comparative Example) An orange toner was prepared in the same manner as in Example except that 1.5 parts by weight of Pyrazolone Orange (manufactured by Sanyo Shiki Co., Ltd.) was used in place of 3-carboxymethyl-5-(p-diethylaminobenzylidene)rhodanine in Example. and a developer was prepared.

(Evaluation) Using the toners of Examples and Comparative Examples produced as described above, a normal color electrophotographic copying machine (Sanda Kogyo Co., Ltd. model DC) 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, an orange 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 mathematical formulas, chemical formulas, tables, etc.▼ (R^1 represents a substituted or unsubstituted alkyl, aralkyl, aryl, or amino group, and R^2 and R^3 are the same A translucent orange toner containing, as a coloring component, a rhodanine derivative represented by the following formula (indicating hydrogen, an alkyl group, a substituted or unsubstituted aryl group).