JPS619657A - Photoconductive toner - Google Patents

Abstract

PURPOSE:To enhance photosensitivity and to enlarge a spectral sensitive region to the whole visible light region by incorporating a specified photoconductive material. CONSTITUTION:The photoconductive material incorporated here is represented by the formula in which Z is an aromatic residue; R1-R4 are each an electron receptive substituent except H, and k, l, m, n are each independently a number of each substituent and 0<=k, l, m, n deg.C2, 1<=k+l<=4, 1<=m+n<=4. Since such a photoconductive material has high photosensitivity, a toner contg. has a spectral sensitivity in the wavelength region of 400-750nm, and superior characteristics in the whole visible light wavelength region, too. Since it is easily soluble in solvents, and good compatibility with fixing resins for use in the toner, too, it can be dispersed uniformly and stably into the photoconductive toner, and it can exhibit superior photosensitivity even if it is incorporated in a small amt. The presence of the azo-methine group in the molecular structure permits photosensitivity to be retained stably even when it is exposed to light and heat for a long period. A sharp image can be obtained by forming a thin layer of this toner on the conductive substrate of a metal plate or the like, electrostatically charging and imagewise exposing it, removing the exposed parts, and transferring it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a photoconductive toner used in electrophotography and the like.

[Technical background of the invention and its problems]

In general, as a copying method in electrophotography, four xerographic methods are employed to obtain a copy by transferring a toner powder image formed on an electrophotographic photoreceptor such as selenium onto plain paper. However, this method requires a development step using toner powder, making the electrophotographic copying apparatus complicated and expensive. In addition, in this method, since the copying system is composed of independent members for the photoreceptor and toner powder (developer), it is also important to consider the performance of one of the two members, for example, the light The deterioration of charging characteristics due to fatigue makes it difficult to obtain high-quality copies.

Therefore, it is necessary to constantly maintain the photoreceptor and toner at a desired level of performance, resulting in problems such as difficult maintenance.

For these reasons, recently, photoconductive toners have been developed that have the functions of both a photoreceptor and a developer. To form an image using such photoconductive toner, the toner is spread onto a conductive support such as a metal plate to form a uniform thin layer, which is then charged and exposed, and further exposed if necessary. After removing the thin layer of toner, transfer is performed.

However, in the exposure of the photoconductive toner, image formation is carried out by flowing the charge of the toner to the support side by light irradiation, so if the photosensitivity of the photoconductive material contained in the toner is low, the toner will be charged. The charged charges do not flow sufficiently to the support side, causing a decrease in sensitivity. In other words, light 4'
Image formation using a high-strength toner is greatly influenced by the photosensitivity of the photoconductive material in the toner, but conventionally it has been difficult to obtain a photoconductive material with sufficient photosensitivity.

[Purpose of the invention]

The object of the present invention is to provide a practical photoconductive toner by developing a photoconductive material that has high sensitivity and is sufficiently sensitive to a wide range of wavelengths. .

[Summary of the invention]

The present invention will be explained in detail below.

The photoconductive material according to the present invention is a photoconductive toner characterized by containing a photoconductive material represented by the general formula σ. 2 in this formula may be any aromatic residue such as diphenyl ether, diphenylmethane, diphenylethane, diphenyl sulfite, diphenyl sulfone, diphenyl disulnide, benzene, and the like. In addition, R1+ R2+ R3 and R4 in the formula accept electrons excluding hydrogen atoms. The reason why the number of substituents is limited in this manner is that if the number of substituents is outside the above range, the photosensitivity of the resulting photoconductive material will be significantly reduced.

Next, regarding the method for manufacturing the photoconductive material according to the present invention,
As representative examples, (+) and (ii) will be shown and explained.

(1) Method for producing a sensitizer in which an aromatic residue of a diamine is introduced into Z in the general formula [I] First, a material consisting of a diamine-based aromatic compound and a fluorenone-based compound is used as a raw material.

Examples of diamine-based aromatic compounds used here include 1,4-diamino-benzene and 2,4-diamino-benzene.
Toluene, α, α′-diamino-m-xylene, 2.4
-diamino-chlorobenzene, 1,4-diamino-2-
Nitrobenzene, 3.5-diamino-rest% r? ,
216-diamitubiridine, 2,4-diamino-6-methyl-s-triazine, 4,6-cyamitsu-S-triazin-2-ol, 1,4-diamino-anthraquinone, 1,5-diamino-naphthalene, 4 .4'-diamino-diphenyl, 4°4'-diamino-diphenyl ether, 4.4'-diamino-diphenylmethane, 4.4'
-diamino-diphenyl sulfide and the like.

On the other hand, fluorenone compounds include, for example, fluorenone, 2-nitro-9-fluorenone, 2゜7-ccitro-9-fluorenone, 2,4.7-') dinitro-9-
Fluoreno/ ,2,4,5.7-tetranitro-9-
Sulfurourenone with a nitro substituent such as fluorenone,
2-chloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dichlorofluorenone, 2-chloro-7-bromo-9-fluorenone, 2,4.7-trichloro-9-fluorenone, 2,4, 5. Norolenones or 2-cyano-9-fluorenones having halogen substituents such as 7-tetrachloro-9-fluorenone, 2
Fluorenone with cyano/substituents such as 7-dicyano-9-fluorenone, 2,4.7-dolycyano-9-fluorenone, 2,4,5.7-tetracyano-9-fluorenone, still 2-nitro-7 -chloro-9-fluorenone, 2-2) 0-7-10ro-9-fluorenone,
2-nitro-7-bromo-9-fluorenone, 2,4-
Dinitro-7-chloro-9-fluorenone, 2-nitro-4,7-dibromo-9-fluorenone, 2,4.5-
to! J nitro 7-chloro 9-fluorenone, 2.7
-Sinitro 4,5-dibromo-9-fluorenone and the like.

Next, a catalyst such as zinc chloride, aluminum chloride, boron trifluoride, ethylate, etc. is added to the above raw material, and then this is refluxed in an inert solvent such as xylene, quinoline, nitrobenzene, etc. to condense it. Making a photoconductive material according to the invention.

(11) Method for producing a photoconductive material in which an aromatic residue of a dinitroso group is introduced into 2 of the above general formula (1) A raw material consisting of a dinitroso aromatic compound and a fluorene compound is prepared in the same manner as in (1) above. The photoconductive material according to the present invention is produced by dehydration condensation using a catalyst and a solvent. Examples of dinitroso-based aromatic compounds used here include 1,4-dinitrosobenzene, 2°4-dinitroso-toluene, and α.

-m-xylene, 2. ．． 4-Dinitron-chlorobenzene, 3,5-dinitroso-benzoic acid, 2,6-cinitrosopyridine, 2,4-danitron-6-methyl-S-
) riazine, 4,6-sinitron-'s-triazine-
2-ol, 1,4-dinitron-anthracene, l,
5-Dinito, Rosonaphthalene.

4.4'-dinitroso-diphenyl, 4. ．． Examples include 4'-dinitroso-diphenyl ethyl, 4,4'-dinitroso-diphenylmethane, and 4,4'-dinitroso-diphenyl sulfide.

On the other hand, fluorene compounds include, for example, fluorene, 2-nitrofluorene, 2,7-cyanofluorene,
2,4.7-)IJ Nitrofluorene.

2.4, 5.7-f) Nitro W such as ranitrofluorene
Fluorene with substituted M, 2-chlorofluorene, 2-
Bromofluorene 0.7-dichlorofluorene, 2-
Fluorenes having no-rogen substituents such as chloro-7-promofluorene, 2゜4.7-)dichlorofluorene, 2,4,5.7-titrachlorofluorene, or 2-cyanofluorene l 217-dichlorofluorene , 2,4.7-) lycyanofluorene, 2,4,5.7
Fluorenes having a cyan substituent such as -thitra-7-amefluorene, or 2-nitro-7-1'lolofluorene, 2-nitro-7-bromofluorene, 2,4-dinitro-7-chlorofluorene, 2-nitro- Examples include 4,7-dibromofluorene, 2,4.5-)+7 nitro 7-chlorofluorene, and 2,7-sinitro 4,5-dibromofluorene. Note that the manufacturing method for obtaining the original tetraelectric material according to the present invention is not limited to the method described above, and it is of course possible to use other manufacturing methods such as the usual in-phase heating melting method using the above raw materials. good.

Representative examples of the photoconductive material according to the present invention obtained in this way will be specifically shown.

a) An aromatic residue such as a diamine or nitrone group is introduced into 2 of the general formula (1), and 1 is introduced into R2 and R4, respectively.
Photoconductive material represented by the general formula into which an electron-accepting substituent excluding hydrogen atoms is introduced: 4.4/-bis-(N,N'-2-nitrofluorene-
9-ylidene)-benzene, 2,4-bis(N.

N'-4-=)rofluorene-9-ylidene-7)-)luene, 1,5-bis-(N,N'-'2-chlorofluoren-9-ylidene)-naphthalene, 4.4'- Bis-
(N,N'-4-bromofluorene-9-ylidene)-
Diphenyl, 4,4'-bis-(N,N'-2-cyanofluoren-9-ylidene) diphenyl ether; 4,
4'-bis-(N,N'-4-cyanofluorene-9-
ylidene)-diphenylmethane, and the like.

b) A general product in which an aromatic residue of a diamine or dinitroso group is introduced into 2 of the general formula [1], and one hydrogen atom is removed from each of R1 + R2 + R3 and R4, and a substituent that accepts <' is introduced. Photoconductive material represented by the formula: 4,47-bis-(N,N'-2,5-dinitrofluorene-9-ylidene)-benzenej2,4-bis-(N
, N'-2,7-sinitrofluorene-9-ylidene)
-Toluene, 1,5-bis-(N,N'-2-nitro-
7-chlorofluorene-9-yritene)-naphthalene,
4.4'-bis-(N,N'-2,5-dichlorosulfolene-9-ylidene)-anthracene.

4.4'-bis-(N,N'-2,7-dipromofluorene-9-ylidene)-diphenyl, 4.4'-bis-
(N,N'-2-chloro-7-dianofluorene-9-
ylidene)-diphenyl ether, 4,4'-bis=(N,N'-2,5-dicia?)luorene-9-yritene)-diphenylmethane, 4,4'-bis-(N.

Examples include N'-2-nitro-7-dianofluoren-9-ylidene)-diphenyl sulfide.

C) An aromatic residue of a diamine or dinitroso group is introduced into 2 of the general formula (1), and an electron-accepting substituent excluding one hydrogen atom in each of R1 and R3, and an electron-accepting substituent in each of R2 and R4. Photoconductive material represented by the general formula into which an electron-accepting substituent excluding two hydrogen atoms is introduced: 4.4'-bis-(N,N'-2,4,5-)dinitrofluorene-9 -ylidene)-benzene, 2,4-bis-(N,N'-2,4,7-)dinitronorolene-9-ylidene)-toluene, 1,5-bis-(N,N
'-2,4-dinitro-7-10rofluorene-9-(
lydene)-naphthalene, 4,4'-bis-(N,N'
-2゜4.5-)1chlorofluorene-9-ylidene)
-Anthracene, 2,6-bis-(N, N'-2,4,
7-Dolipromofluorene-9-ylidene)-pyridine, 4,4'-bis-(N,N'-2,4-dichloro-7
-dianofluorene-9-ylidene)-diphenyl.

4.4'-bis-(N,N'-2,4,5-)phosphorusanofluoren-9-ylidene)-diphenyl ether.

4.4'-bis-(N,N'-2,4,7-1-dicyanofluoren-9-yritene)-diphenylmethane.

4.4'-bis-(N,N'-2,4-dicyano-7-
Nitrofluorene-9-ylidene)-diphenyl sulfide.

d) Introducing an aromatic residue of a diamine or dinitroso group into 2 of the general formula [1], and R1+R2+R3 and R
A photoconductive material represented by the general formula in which an electron-accepting substituent excluding two hydrogen atoms is introduced into 4: 4.4'-bis-(N,,N'-2,4,5,7 -Tetranitrofluoren-9-ylidene)-benzene, 2゜4-bis-(N,N'-2,4,5-trinitro7-chlorofluoren-9-ylidene)-toluene, 1
゜゜'5-bis-(N,'M'-2,7-dinihero4,5
-dibromofluorene-9-ylidene)-naphthalene.

4.4'-bis-(N,N'-2,4,5,7-tetrachlorofluoren-9-ylidene)-anthracene, 4
゜4'-Hydroxy(N,N'-2,4,5,7-tetrabromofluoren-9-yritene)-diphenyl, 4
．． 4'-bisbeN'-2,7-dichloro-4',5-
Dicyanofluorene-9-ylidene)-diphenyl ether, 4,4'-bis-(N,N'-2,4,5,7-
Examples include tetracyanofluoren-9-ylidene)-diphenylmethane, 4,4'-bis-(N,N'-2,7-dicyate-4,5-dinitrofluoren-9-ylidene)-diphenyl sulfide, and the like. The photoconductive material represented by the general formula (1) according to the present invention is usually used as a toner fixing resin such as polyester, polycarbonate, styrene, styrene-acrylic, acrylic, and methacrylic.

The photoconductive toner of the present invention is prepared by dispersing or coating it in vinyl chloride, epoxy, phenol, urethane resin, or the like. Furthermore, in order to increase photosensitivity, a so-called low molecular weight organic photoconductor or photoconductive polymer may be mixed into the photoconductive toner. Specific examples of the former include arylalkane, pyrazoline, oxadiazole, hydrazone, triphenylamine, fuyenylenediamine, biphenylamine, cal)<Y-
Examples of the latter polymer include known polyvinylphenylanthracene, polyvinylpyrazoline, polyvinylbenzothiophene, polyvinylpyrene, and derivatives thereof.
.

Next, one example of the method for producing the photoconductive toner of the present invention will be specifically described.

First, after producing fine particles mainly composed of the photoconductive material shown in the general formula (1), the fine particles are mixed with a fixing resin for toner in a suitable solvent using a ball mill or the like. Mix and disperse thoroughly. Next, it may be spray-dried using a spray dryer, a subirocoder, or the like. The photoconductive toner thus produced has a particle size of approximately 10 μm.

The ratio of the photoconductive material to the toner fixing resin is preferably 0.1 to 80 parts by weight per 100 parts by weight of the toner fixing resin. The reason is that if the photoconductive material is less than 0.1 part by weight, no sensitizing effect can be achieved, and if it exceeds 80 parts by weight, no significant improvement in the sensitizing effect is observed by adding more. This is because the toner fixing performance is also inhibited.

However, since the photoconductive material represented by the general formula (1) in the present invention has extremely high photosensitivity, the photoconductive toner containing this photoconductive material has approximately 400 to
It has spectral sensitivity over a wavelength range of 750 nm and exhibits excellent photosensitivity characteristics in the entire visible light wavelength range. Furthermore, this photoconductive material is easily dissolved in solvents and has good compatibility with toner fixing resins, so when dispersed in photoconductive toner, it can be dispersed evenly and stably, and even in small amounts, it has excellent properties. Demonstrates photosensitivity characteristics. It also has two azomethine bonds in its structure, which allows it to emit light.

More stable photosensitivity can be maintained even when exposed to heat for a long time.

1. In order to apply the photoisoelectric toner of the present invention to electrophotography, the toner is dispersed onto a conductive support such as a metal plate to form a uniform thin layer, which is then charged and exposed to light. Transfer may be performed after removing the exposed toner M portion according to the following.

[Embodiments of the invention]

Next, the present invention will be explained in detail. In the examples, "part" means "part by weight" and "chi" means "weight".

Example 1 If 0.2 part of zinc chloride was added to a raw material consisting of 2 parts of 4,4'-diamino-diphenyl ether and 225 parts of 2,4.7-)dinitro-9-fluorene, and while stirring and mixing, Melt by heating at 200°C for 1 hour, and after cooling, extract with chloroform and concentrate.

The precipitated red solid was filtered off and then recrystallized from chloroform to yield 4,4'-bis-(N,N'-2,4,7-)dinitrofluoren-9-ylidene as a photoconductive material. )-diphenyl ether (2 parts) was obtained.

Next, 3 parts of styrene-methacrylic resin was mixed with 15 parts of toluene.
To this, 2 parts of the above sensitizer dissolved in 5 parts of dioxane was added, and the mixture was mixed in a ball mill for 3 hours to prepare a photoconductive composition. This composition was spray-dried using a spray dryer and then dried at 40°C for 5 hours to produce a photoconductive toner having an average particle size of 8 to 10Rn.

When we measured the photosensitivity and spectral sensitivity of this toner, we found that the photosensitivity and spectral sensitivity of this toner were 3101 ux"sec and 450 to 70 ux"sec, respectively.
0 books, and as a comparative pigment, for example, Heliogen
Blue (product name: BASF) 50001uX-
It had sufficient photosensitivity compared to the values of 8ec and 600 to 900 nm, and spectral sensitivity that did not vary over the entire visible light region.

Next, this photoconductive toner was spread uniformly onto the aluminum substrate so as to form a single layer, this toner single layer was corona charged at -6.0 kV in a dark place, and image exposure was then performed. After forming an electrostatic latent image and removing the toner in the exposed area where the electrostatic attraction has weakened using an air blower,
Plain paper is placed on top of this, corona charging of +6.5 kV is applied from the paper side, and the toner in the latent image area is transferred onto the plain paper.
Furthermore, heat fixing was performed. As a result, a red positive image with high density was formed on the plain paper.

Example 2 1.6 parts of 4.4'-diaminodiphenylmethane and 2
, 7-sinitro, 9-fluorenone, and 0.2 parts of aluminum chloride were mixed with 5 parts of aluminum chloride and subjected to the same heat-melting and extraction steps as in Example 1 to obtain 4,4'- as a phototetraelectric material. 1.2 parts of bis-(N,N'-2,7-sinitrofluoren-9-ylidene)-diphenylmethane were obtained.

Next, 2 parts of the polyester resin was dissolved in toluene, and 08 parts of the above photoconductive material dissolved in 30 parts of chloroform was added thereto to prepare a photoconductive composition. Subsequently, this composition was treated in the same manner as in Example 1 to form a layer of 9 to 12 μm.
A photoconductive toner having a particle size of .

When the photosensitivity and spectral sensitivity of this photoconductive toner were measured, they were 4701 uX"sec and 400 to 70 sec, respectively.
0 nm, and as a comparative pigment, for example, PV Fast
4' of Red B (product name: Hoechst)
3001ux・sec.

It had sufficient photosensitivity and spectral sensitivity in a wider range compared to the value of 400 to 600 nm.

Then, when this photoconductive toner was used to form an image in the same manner as in Example 1, a clear orange positive image was formed on plain paper.

Example 3 3.5 parts of 1,4-dinitron benzene and 2,4°5
．． A raw material consisting of 10 parts of 7-titrachlorofluorene was refluxed in 500 parts of ethanol, then 1 part of 1 volume of 1% ethylate was added thereto, and reflux was continued for 2 hours. After cooling, the precipitated red crystals were filtered and recrystallized with chloroform to obtain 4,4'-bis-(N,N'-
2,4,,5,7-Tetrachlorofluoren-9-ylidene)-benzene was obtained.

Next, 2 parts of poly-N-vinylcarbazole and 3 parts of acrylic resin were dissolved in 50 parts of chlorobenzene in a heating bath, and 2 parts of the above-mentioned phototetraelectric material was added thereto along with 3 parts of tetrahydrofuran, followed by stirring and mixing in a ball mill for 2 hours. A photoconductive composition was obtained. Subsequently, this was spray-dried using a Subirocoder to produce a photoconductive toner consisting of fine particles with a particle size of 7 to 9 μm.

When the photosensitivity and spectral sensitivity of this photoconductive toner were measured, they were 5001 ux@sec and 400 to 750, respectively.
nm, and as a comparative pigment, for example, IndofastY
yellow (product name: Harmon Colors) 80001ux・sec, 400-500n
It had sufficient photosensitivity and spectral sensitivity in a wider range compared to the value of m.

The obtained photoconductive toner was formed into a thin layer of about 100 μm on a transparent electrode of In5nOx, and sandwiched between a plain paper and a counter electrode in that order through a one-plate thick spacer. Next, the transparent electrode side is -1, 5 with the transparent paper type and the opposite '1' being the polar curve.
The pore area was marked so as to be KV, and at the same time, image exposure was carried out from the transparent electrode side.

When the plain paper was taken out after exposure, the image-exposed photoconductive toner moved onto the plain paper and formed an image, yielding a clear red negative image. On the other hand, a positive image, which is the unexposed part of the image, remained on the transparent electrode.

Example 4 First, 0.1 part of boron tri-7-ionide was added to a raw material consisting of 2 parts of 1,4-diamino-2-nitrobenzene and 5 parts of 2-cyano-9-fluorenone. Melt and extract in a PA bath using the same method.

Concentrate and precipitate the following 414 as a photoconductive material
Three parts of 4,4'-bis-(N,N'-2-cyanofluorene-9-ylidene)-2-=)I:1 benzene represented by the formula were obtained.

Next, 5 parts of epoxy resin was dissolved in 50 parts of toluene,
2 parts of the above photoconductive material and 1 part of carbazole were added and dissolved together with 20 parts of dioxane to obtain a photoconductive composition.

Subsequently, this composition was spray-dried by a spray-drying method to produce a photoconductive toner having an average particle size of 11 to 13 μm.

When the photosensitivity and spectral sensitivity of this photoconductive toner were measured, they were 6301uxlIsec and 400-sec, respectively.
750 parts m, and as a comparative pigment, for example, C1quasi
a Red (black market name: DuPont) 57001
It had sufficient photosensitivity and spectral sensitivity in a wider range compared to the value of ux@sec, 400-580 nm.

This photoconductive toner was then formed into a thin layer on an aluminum plate, positively charged in the dark according to the known corona charging method, and then placed in a photographic enlarger using a light source consisting of 1000 lux white light. When image exposure was carried out using this method, and then plain paper was layered and corona transfer was performed from the back side, an extremely clear positive image with no difference from the original pattern was obtained on the plain paper.

[Effects of the Invention] The photoconductive material according to the present invention not only has high photosensitivity, but also can extend the spectral sensitivity range to the entire visible light range. A wide range of photoconductive toners can be obtained.

Agent: Patent Attorney Noriyuki Chika (1 other person)

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [However, in the formula, Z is an aromatic residue, R_1, R_2, R_3
and R_4 is an electron-accepting substituent other than a hydrogen atom, k,
l, m, n indicate the number of the same or different substituents, and the number is 0≦k, l, m, n≦2, and 1≦k+l≦4,
1≦m+n≦4] A photoconductive toner characterized by containing a photoconductive material represented by the following formula.