JPS61230154A - 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 (the 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 using the bisazo compd. as mentioned above, as 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.

Image formatting methods using electrophotography are widely known.

The conventional method is to charge the entire surface of the photoreceptor by corona discharge, and then imagewise expose the photoreceptor to light, so that the exposed portion of the photoreceptor becomes conductive and loses its charge, 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, making the process up to development extremely simple.

The structure of the device can also be made 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 improved by applying a charge to the photoconductive toner in advance and erasing the charge by irradiation with light. It's something you get.

The photoconductive material used in this method is:

Conventionally, inorganic photoconductive substances such as Se and CdS dye-sensitized ZnO, and organic photoconductive substances 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;
Poor dispersibility of the material into the toner.

Another problem is that it lacks thermal stability.

And - one loss 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.

■−−belly 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. Ta.

The coupler in the general formula (1) 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 general formula (■) below.

(III), (It/), (V), (VI), (■
), (■), (IN), (X), (XI), (XU)
It is expressed by the general formula:

(Left below) [In the above formulas (n), (m), (mV) and (V),
, Y, , Z, m and n each represent the following.

R□ X: -OH, -N or -NH5O, -R.

(R1 and R3 represent hydrogen or a substituted or unsubstituted alkyl group, and R3 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Yl: hydrogen, halogen, substituted or unsubstituted alkyl Base! Exchange it! ! Substituted alkoxy group, carboxy group, sulfo group, substituted or unsubstituted sulfamoyl group or 100N-Y.

(R4 represents hydrogen, an alkyl group or a substituent thereof, a phenyl group or a substituent thereof, and Y is a hydrocarbon ring group or a substituent thereof, a heterocyclic group or a substituent thereof.

R1 or -N=C (however, R6 is a hydrocarbon group or a substituent thereof, a heterocyclic group or a substituent thereof, a styryl group or a substituent thereof, R6 is hydrogen, an alkyl group, a phenyl group or a substituent thereof or R1 and R6 may form a ring together with the carbon atoms bonded to them. Integer m: an integer of 1 or 2] [In formulas (Vl) and (■), R7 represents a substituted or unsubstituted hydrocarbon group, or is the same as above. ] r1 [In the formula, R8 represents an alkyl group, a carbamoyl group, a carboxyl group, or an ester thereof, Ar□ represents a hydrocarbon ring group or a substituent thereof, and X is the same as above. [In the above formulas (ff) and (X), R9 represents hydrogen or a substituted or unsubstituted hydrocarbon group, and Arl represents a hydrocarbon ring group or a substituted product thereof. ] The above general formula (■), (nr), (rv) or (V)
Examples of the hydrocarbon ring for Z 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 R5, ]
Examples include phenyl group, naphthyl group, anthryl group, pyrenyl group, etc., and examples of heterocyclic groups include pyridyl group, chenyl group, furyl group, indolyl group, benzofuranyl group, carbazolyl group, dibenzofuranyl group, etc. Further, examples of the ring formed by bonding R6 and 'JR include a fluorene ring and the like.

Examples of substituents for the hydrocarbon ring group or heterocyclic group of Y2 or R, or the ring formed by R9 and R1 include a methyl group and an ethyl group.

Alkyl groups such as propyl and butyl groups, methoxy groups,
Alkoxy groups such as ethoxy groups, propoxy groups, butoxy 1, halogen atoms such as chlorine atoms and bromine atoms, dialkylamino groups such as dimethylamino groups and dimethylamino groups, dialkylamino groups such as dialkylamino groups,
Halomethyl groups such as trifluoromethyl groups, nitoco groups,
Examples include a cyano group, a carboxyl group or an ester thereof, a hydroxyl group, and a sulfonic acid group such as 5o3Na.

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

Representative examples of the hydrocarbon group in R7 or R9 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 R3,
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 Ar1 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 a halogen atom, a cyano group, a dimethylamino group, a dialkylamino group such as a diethylamino group.

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, it is preferable that X in the general formula is a hydroxyl group; ) to Z' (Y□ and Z are the same as above) are preferred, and more preferably are coupler residues represented by the general formula (z, ys and R yo are the same as above) .

Furthermore, among the above-mentioned preferred coupler residues, the general formula (XIII) or (XIV) is HOCONHN=C, and R4° is exemplified by the above-mentioned substituent of 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 considering the efficiency of dispersion, 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 "lower 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-acrylate
Esters of α-methylene aliphatic monocarboxylic acids such as chloro-ethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, e.g. vinyl Monomers such as vinyl ethers such as methyl ether, vinyl isobutyl ether, and vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, and N-vinyl compounds such as N-vinylvirol and N-vinylcarbazole are polymerized. copolymers or mixtures thereof, such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins, polyether resins, etc. Examples include non-vinyl resins such as non-vinyl thermoplastic resins, and mixtures thereof with vinyl resins such as those 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 acid ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer.

ionomer resin), polyvinylpyrrolidone.

Methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin.

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 the most preferred because it is desirable to have the following fine particles that can be easily obtained.6 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, steel oxide, nickel oxide, zinc oxide, titanium oxide, and magnesium oxide; vanadium nitride.

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 20 parts per part (1 part by weight).

When the purpose is color magnetic toner, γ-Fe, O,
A type of brown magnetic material or magnetic powder whose color is hidden by surface treatment is used.

In addition, 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 disazo compounds exemplified in the table above.

Example 1 A mixture consisting of 30 parts by weight of polystyrene resin, 70 parts by weight of disazo compound 3, and 500 parts by weight of toluene was dispersed for 10 hours using a ball mill dispersion method to obtain uniform dispersion. After removing toluene, thoroughly dry in a vacuum dryer, pulverize in a jet mill, and then use air classification to
The toner was classified into particle sizes of 12 μm and a toner with a particle size of 12 μm was obtained.

This photoconductive toner was mixed with 1. A thin layer of toner is formed on an aluminum drum so that the toner concentration is less than .omg/d.

Afterwards, a -6KV corona charge was applied.

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 Disazo compound N1117 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.The same tests as in Example 1 were conducted using the same toner, and good results were obtained in all cases.

Example 3 Styrene acrylic resin 30 parts by weight Disazo compound & 29 70 parts by weight Toluene
A mixture consisting of parts by weight of SOO 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 Disazo compound N (116,870 parts by weight Toluene SO
A mixture consisting of parts by weight of O 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 described 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.