JPS61230157A - Photoconductive toner - Google Patents

Abstract

PURPOSE:To obtain the titled toner having a good sensitivity and an excellent dispersion and thermal stability by incorporating a specific bisazo compd. to a binding resin. CONSTITUTION:The binding resin contains the bisazo compd. shown by the formula wherein A is a coupler residue. The coupler shown in the formula comprises for example, an aromatic hydrocarbon having a hydroxyl group such as a phenol and a naphthol; a heterocyclic compd. having a hydroxyl group, an aromatic hydrocarbon having an amino group, a heterocyclic compd. having an amino group, a heterocyclic compd. having an amino group, an aromatic hydrocarbon and a heterocyclic compd. having a hydroxy group and an amino group such as aminonaphthol and a compd. having an aliphatic or an aromatic ketone in an enolic form (a compd. having an active methine group). The compounding ratio of the binding resin and the bisazo compd. is preferable to be a range of 1:0.5-1:5. The titled toner having the good sensitivity and the excellent dispersibility and thermal stability is obtd. by incorporating the bisazo compd. as mentioned above, to the photoconductive material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrophotography, and particularly to a photoconductive toner used in a method that does not use a photoreceptor.

U1 Technique - The electrophotographic image formatting method is widely known.

In the usual formal method, the entire surface of the photoreceptor is electrically charged by corona discharge, and then imagewise exposed.The exposed portion of the photoreceptor becomes conductive and the charge disappears, leaving the unexposed portion as an electrostatic latent image. When toner of opposite polarity is brought close to this electrostatic latent image, the toner is electrostatically attracted and the latent image is visualized. In one type of xerography, the image is transferred to plain paper and fixed, and in the electrofax method, it is directly fixed on a photoreceptor. The problem with these methods is that these processes are complex and require advanced control technology to maintain high quality images because the photoreceptor, which is a completely different material from the toner material, is used at the same time. That's a thing.

Because of this problem, attempts have been made to simplify the process without the use of photoreceptors through the use of photoconductive toners. This is completely different from the above-mentioned single xerography system and electrofax system, in that the photoreceptor and the image forming body are the same. That is, an image forming toner having a photoreceptor is used and also functions as the photoreceptor.

This eliminates the need for a photoreceptor to be controlled, so the process up to development becomes extremely simple, and the structure of the device becomes simple and inexpensive.

Electrophotography using a photoconductive toner includes the Sugarman method (US Pat. No. 2,758,939), and its variations include a combination method of photoconductive toner and corona discharge, and an electrophoresis method.

From this concept, the present invention is similar to photoconductive toner and corona discharge, and the toner charge amount contrast is increased by applying an electric charge to the photoconductive toner in advance and erasing the electric charge by irradiation with light. It's something you get.

Conventionally, the photoconductive material used in this method is Se.
, CdS dye-sensitized ZnO, and organic photoconductive materials such as copper phthalocyanine and polyvinylcarbazole-trinitrofluorenone have been investigated.

The problem with these materials is that the toner powder layer does not have the required functions, namely the ability to generate a charge above a certain value, the ability to retain this charge, and the ability to form a desired charge contrast by light exposure. Everything is not fully equipped.

As a result, there are many restrictions when forming a system, and it is because of these restrictions that there are few examples of practical implementation.

The reason for this is that the sensitivity of the photoconductive material itself is low;
Examples include poor dispersibility of the material in the toner and lack of thermal stability.

l-one time The present invention has been made in view of the above circumstances.

The objective is to provide a photoconductive toner containing a photoconductive material that is thermally stable, has good dispersibility, and in which the toner powder layer sufficiently retains the required functionality. It is something to do.

Eiichi-ku The present invention is the result of intensive research to achieve the above object.

It has been found that the above object can be achieved by providing a photoconductive toner characterized by containing a compound represented by the following general formula (wherein A represents a coupler residue) in a binder resin.

The coupler in the general formula (I) is as follows.

For example, aromatic hydrocarbon compounds having a hydroxyl group such as phenols and naphthols, heterocyclic compounds having a hydroxyl group, aromatic hydrocarbon compounds having an amino group and heterocyclic compounds having an amino group, and hydroxyl groups such as aminonaphthols. and aromatic hydrocarbon compounds and heterocyclic compounds having an amino group, compounds having an aliphatic or aromatic enolic ketone group (compounds having an active methylene group), etc., and preferably coupler residue A. is the following general formula (II), (m), (mV), (V)
, (VI), (■), (■), (■).

They are represented by the general formulas (X), (XI), and (Xll).

(Margins below) [Formula (II), (m), (IV) and (V) above
During.

X, Yl, Z, m and n each represent the following 6 RyuX: -OH, -N or -NH8O, -R.

(Rt and R2 represent hydrogen or a substituted or unsubstituted alkyl group, R□ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Yl: hydrogen, halogen, I-substituted or unsubstituted an alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfo group, a substituted or unsubstituted sulfamoyl group, or 100N-Y.

(R represents hydrogen, an alkyl group or a substituent thereof, a phenyl group or a substituent thereof, and Y2 is a hydrocarbon cyclic group or a substituent thereof, a heterocyclic group or a substituent thereof.

R.

or -N=C (where R1 is a carbide R1, a hydrogen ring group or a substituent thereof, a heterocyclic group or a substituent thereof, a styryl group or a substituent thereof; R is hydrogen, an alkyl group, a phenyl group or a substituent thereof; or R6 and R1 may form a ring together with the carbon atoms bonded to them.) 2: Hydrocarbon ring or its substituted product or heterocycle or its substituted product n: 1 or 2 Integer m: an integer of 1 or 2] [In formulas (VI) and (■), R7 represents a substituted or unsubstituted hydrocarbon group, or is the same as above. ] rc [In the formula, R represents an alkyl group, a carbamoyl group, a carboxyl group, or an ester thereof, Ar1 represents a hydrocarbon ring group or a substituent thereof, and X is the same as above. [In the above formulas (IK) and (X), R1 represents hydrogen or a substituted or unsubstituted hydrocarbon group, and Ar1 represents a hydrocarbon ring group or a substituted product thereof.] The above general formula (■), ( Examples of the hydrocarbon ring of Z in II), (IV) or (V) include a benzene ring and a naphthalene ring, and examples of the heterocycle include an indole ring, a carbazole ring, and a benzolane ring. Examples of substituents on the ring of Z include halogen atoms such as chlorine atoms and bromine atoms, and alkoxy groups.

As the hydrocarbon ring group in Y2 or R9.

Examples include phenyl group, naphthyl group, anthryl group, pyrenyl group, and heterocyclic groups include pyridyl group, chenyl group, furyl group, and indolyl group.

Examples include a benzofuranyl group, a carbazolyl group, and a dibenzofuranyl group. Furthermore, examples of the ring formed by combining R1 and R6 include a fluorene ring.

Substituents on the hydrocarbon ring group or heterocyclic group of Y2 or R2 or the ring formed by R5 and R5 include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, methoxy group, ethoxy group, propoxy alkoxy groups such as butoxy groups, halogen atoms such as chlorine atoms and bromine atoms, dialkylamino groups such as dimethylamino groups and diethylamino groups, dialkylamino groups such as dibenzylamino groups, and halomethyl groups such as trifluoromethyl groups. , a nitro group, a cyano group, a carboxyl group or its ester, a hydroxyl group, and a sulfonic acid group such as -8O and Na.

Examples of substituents for the phenyl group of R4 include halogen atoms such as chlorine atoms and bromine atoms.

Representative examples of the hydrocarbon group in R7 or R are:
Examples include alkyl groups such as a methyl group, ethyl group, propyl group, and butyl group, aralkyl groups such as benzyl group, aryl groups such as phenyl group, and substituted products thereof.

As a substituent in the hydrocarbon group of R7 or R,
Examples include alkyl groups such as methyl, ethyl, propyl, and butyl groups; alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy; halogen atoms such as chlorine and bromine; hydroxyl and nitro groups. .

Typical examples of the hydrocarbon ring group in Ar□ or Ar are phenyl group, naphthyl group, etc.
Substituents for these groups include alkyl groups such as methyl, ethyl, propyl, and butyl, alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy, nitro, chlorine, bromine, etc. Examples include halogen atoms, dialkylamino groups such as cyano groups, dimethylamino groups, and diethylamino groups.

Furthermore, among X, a hydroxyl group is particularly suitable.

Among the above coupler residues, preferred is the general formula (
m), (VI), (■), (■), (IK) and (X
), and among these, those in which X in the general formula is a hydroxyl group are preferred; Preferably, and more preferably, a coupler residue represented by the general formula (Z, Y, and R2 are the same as above).

Furthermore, among the above-mentioned preferred coupler residues, general formula (XIII) or (XIV) R6 HOCONHN=C, and R1. Examples of the substituent include the above-mentioned substituent Y2. ) is appropriate.

Typical examples of the photoconductive material according to the present invention include the materials shown on the following pages.

A typical method for synthesizing the photoconductive material according to the present invention is 1, for example, according to the method described in JP-A-53-133229.

The particle size of photoconductive materials differs depending on the synthesis procedure and material properties, but when considering dispersion efficiency, finer particles are preferable.The particle size of the final toner particles is generally 5-30μ. and preferably 7-15μ
It is.

The ratio of the binder resin to the photoconductive material is set based on sensitivity and charge retention, and varies depending on the characteristics of the synthesized compound, but is generally preferably in the range of about 1:0.5-1=5. The optimum ratio is 1:1-1:3.

The optimum content of the colorant varies depending on the content ratio of other materials, but it is about 5 parts by weight at most per 100 parts by weight of the resin. In many cases.

1-2 parts by weight is sufficient.

(Hereinafter referred to as margin) (hereinafter referred to as margin) (hereinafter referred to as margin) (hereinafter referred to as margin) (hereinafter referred to as margin) (hereinafter referred to as margin) (hereinafter referred to as margin) The photoconductive toner according to the present invention can be widely used as a binder resin, including known binder resins. .

For example, styrenes such as styrene and parachlorostyrene, vinylnaphthalene, vinyl esters such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, and methyl acrylate. , ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate.

2-chloro-ethyl acrylate, phenyl acrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, such as vinyl methyl ether, vinyl isobutyl ether, Polymers obtained by polymerizing monomers such as vinyl ethers such as vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, and N-vinyl compounds such as N-vinylvirol and N-vinyl carbazole. copolymers or mixtures thereof, such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins,
Examples include non-vinyl resins such as non-vinyl thermoplastic resins such as polyether resins, or mixtures of these and vinyl resins as described above.

In addition, the following materials are particularly limited to pressure fixing materials.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, oxidized polyethylene, polytetrafluoroethylene, etc.), epoxy resin, polyester resin (oxidation 10 or less)
, styrene-butadiene copolymer (monomer ratio 5-30
: 95-70) *'Olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic ester copolymer, ethylene-vinyl chloride copolymers, ethylene-vinyl acetate copolymers, ionomer resins), polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride copolymers, maleic acid-modified phenolic resins, phenol-modified terpene resins.

In addition to the resin, the toner of the present invention may optionally contain pigments,
Optional colorants such as dyes can be added. These colorants are known, such as carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate. , lamp black, oil black, azo oil black, rose bengal and mixtures thereof. .

In addition, when used as a toner containing a magnetic material, the magnetic material is chemically stable, and the particle size is 1 μm.
Magnetite (triiron tetroxide) is most preferable because the following fine particles can be easily obtained. Typical examples of magnetic or magnetizable materials include cobalt and iron.

Metals such as nickel, aluminum, cobalt, copper,
Iron, lead, magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium.

Alloys of metals such as titanium, tungsten, vanadium and mixtures thereof; aluminum oxide.

Metal compounds including metal oxides such as iron oxide, copper oxide, nickel oxide, zinc oxide, titanium oxide, and magnesium oxide; vanadium titanide.

Refractory nitrides such as chromium nitride; carbides such as tungsten carbide and silica carbide; ferrites and mixtures thereof, and the like may be used.

These ferromagnetic materials preferably have an average particle size of about 0.1 to 1 μm, and are contained in the toner in an amount of about 50 to 300 parts by weight per 100 parts by weight of the resin component, particularly preferably 100 parts by weight of the resin component. 90 to 200 parts by weight.

For color magnetic toner, γ-Fe, On
A type of brown magnetic material or magnetic powder whose color is hidden by surface treatment is used.

Further, the toner of the present invention can be used together with a fluidizing agent if necessary, and the fluidizing agent is preferably a fine powder of hydrophobic silica, titanium oxide, aluminum oxide, etc., and the amount used is in accordance with the toner. 0.1 to 1% by weight
is preferred.

The present invention will be explained below with reference to examples, but the present invention is not limited to these examples.

The photoconductive materials used in the examples were obtained according to the synthesis examples described above, and were obtained from the trisazo compounds exemplified in the table above.

Example 1 Polystyrene resin 30 parts by weight Trisazo compound Na25 70 parts by weight Toluene
A mixture consisting of 500 parts by weight was dispersed for 10 hours using a ball mill dispersion method to achieve uniform dispersion. After removing toluene, it is thoroughly dried in a vacuum dryer, pulverized in a jet mill, and then classified into particles with a particle size of 5 to 30μ by wind classification.
A 2μ toner was obtained.

A thin toner layer was formed on an aluminum drum so that the photoconductive toner was 1.0I1g/a# or less, and then corona charging was performed at -6KV.

One layer of toner was uniformly charged and imagewise exposed to form an electrostatic latent image on the one layer of toner. A single layer of toner retaining this charge distribution was subjected to a +5.8 KV corona charge via a transfer paper, and the single layer of toner on the aluminum drum was transferred and separated onto the transfer paper to obtain a desired image.

Example 2 Epoxy resin 30 parts by weight Trisazo compound Nα130 70 parts by weight Toluene
A mixture consisting of 500 parts by weight was treated in the same manner as in Example 1 to obtain a toner having a particle size of 12 μm.

When the same tests as in Example 1 were conducted using this toner, good results were obtained in all cases.

Example 3 Styrene acrylic resin 30 parts by weight Trisazo compound Na131 70 parts by weight Toluene
A mixture consisting of 500 parts by weight was treated in the same manner as in Example 1 to obtain a toner having a particle size of 12 μm.

When the same test as in Example 1 was conducted using this toner, clear images were obtained.

Example 4 Polyester resin 30 parts by weight Trisazo compound Na147 70 parts by weight Toluene
A mixture consisting of 500 parts by weight was treated in the same manner as in Example 1 to obtain a toner having a particle size of 12 μm.

When the same test as in Example 1 was conducted using this toner, clear images were obtained.

As mentioned above, according to the present invention, a toner with good sensitivity, excellent dispersibility, and thermal stability can be obtained.

[Brief explanation of drawings]

The accompanying drawings are schematic cross-sectional views of the photoconductive toner of the present invention.

Claims (1)

[Claims] 1. Characterized by containing a compound represented by the following general formula ▲Mathematical formula, chemical formula, table, etc.▼(I) (in the formula, A represents a coupler residue) in the binder resin. photoconductive toner.