JPS60203957A - Photosemiconductor material - Google Patents

Abstract

PURPOSE:To improve the photosensitivity and aging stability by combinedly using unstable phthalocyanine as a photosemiconductor and a phthalocyanine deriv. which stabilizes the phthalocyanine crystals to an org. solvent. CONSTITUTION:Unstable or metastable phthalocyanine (Pc) such as Pc having alpha- or epsilon-crystal form is combined with a Pc deriv. which stabilizes the Pc crystals to an org. solvent. Any Pc deriv. which stabilizes the Pc semiconductor crystals may be used as the Pc deriv., and it includes piperidinomethyl copper Pc. They are mixed in a nearly uniform state and have high shelf stability. The resulting photosemiconductor material is mixed with a binder resin or vapordeposited to form a photosensitive layer. A semiconductor having high photosensitivity, aging stability and superior noncoagulability or crystal stability can be obtd. by combining the unstable Pc semiconductor with the Pc deriv. which stabilizes the Pc crystals. The semiconductor may be used as laser.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical semiconductor material with excellent storage stability using a phthalocyanine composition containing a phthalocyanine derivative. Furthermore, electrophotographic properties.

For example, it has excellent light sensitivity and image quality stability with repeated use,
The present invention also relates to a photosemiconductor material that can provide electrophotographic photoreceptors with excellent hygiene properties.

Applications of optical semiconductor materials include electrophotographic photoreceptors, photovoltaic cells, electrophotographic plate-making materials, sensors, and the like.

In general, electrophotography involves xerography, in which a photoconductor made of a thin film of photoconductor such as selenium or cadmium sulfide is formed on a metal drum, is charged in a dark place, and a light image is irradiated (exposed). After forming an electrostatic latent image, a visible image is created with toner (development), and this is transferred and fixed onto paper, etc., or a photoconductive layer (photosensitive layer) is provided on paper as in the electrofax method. There is a method of obtaining a permanent visible image on the photoconductive layer by charging, exposing, developing and fixing the photoreceptor.

Inorganic compounds that are currently widely used as optical semiconductor materials for electrophotographic photoreceptors include amorphous selenium, cadmium sulfide, and zinc oxide.

On the other hand, as an organic compound, polyvinylcarbazole (
PVK), phthalocyanine, azo, etc. are known. Although these optical semiconductors have excellent flexibility and processability, they do not have sufficient electrophotographic sensitivity for practical use when used alone, and they can be sensitized by combining chemical sensitization and optical sensitization. Ru.

Chemical sensitizers include polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitro-9-fluorenone (TNF) and 2,4,5,7-tetranitro-9-fluorenone (TENF), and anthraquinone. Quinones and nitrile compounds such as tetracyanoethylene are known.

Furthermore, xanthine dyes and quinoline pigments are known as optical sensitizers.

Phthalocyanine photosemiconductors provide excellent electrophotographic photoreceptors among organic photosemiconductors. When in contact for a period of time, these phthalocyanines gradually become coarse particles and finally transform into stable β-type phthalocyanine. This is also observed in the production of electrophotographic photoreceptors using phthalocyanine. That is, the size and shape of phthalocyanine particles change as seen when phthalocyanine is dispersed in a vehicle or solvent such as a paint. Or a phenomenon accompanied by a change in the crystal state is observed. As a result, the physical properties of the phthalocyanine may change significantly and its commercial value may be impaired. This tendency is particularly strong in unstable or semi-unstable phthalocyanines, and improvement thereof is desired. For example, when an electrophotographic photoreceptor is prepared by coating a conductive support with a coating material in which phthalocyanine photosemiconductors are dispersed in a resin and an organic solvent, the phthalocyanine aggregates or aggregates during storage of the coating material, and This causes crystal transition or coarsening of phthalocyanine particles, resulting in deterioration of electrophotographic properties. Alternatively, when the resin is thermally cured after being applied to a conductive support using a coating agent, coarsening of crystal particles and crystal transition are caused. Also, low molecular weight.

If a charge transfer agent with a relatively low melting point is used in combination, the phthalocyanine will gradually coarsen or undergo crystal transition when used at high temperatures, resulting in significant deterioration of electrophotographic properties. This is a disadvantage of using unstable or semi-unstable phthalocyanines.

The present inventors conducted various studies to solve the above-mentioned drawbacks, and found that organic solvents such as aromatic compounds, plasticizers,
By combining a fucrocyanine derivative that stabilizes phthalocyanine crystals against other low-molecular-weight organic compounds with an unstable or quasi-unstable phthalocyanine photosemiconductor, it not only has excellent photosensitivity and stability over time, but also non-aggregation. The present invention was accomplished by discovering an optical semiconductor material with excellent properties and crystal stability. In the present invention, the mixing method is not particularly limited, and two various methods may be used.

Furthermore, the present invention solves the above-mentioned drawbacks, and does not require chemical sensitizers that cause problems such as hygiene.
The present invention relates to a photosemiconductor material containing a phthalocyanine composition that has photosensitivity comparable to that of a cadmium sulfide photoreceptor, has excellent sensitivity stability after repeated use, is industrially useful, and has excellent hygiene properties. That is, it is an optical semiconductor material consisting of an unstable or semi-unstable phthalocyanine optical semiconductor and a phthalocyanine derivative that stabilizes the crystals of the phthalocyanine.

Additionally, some methods are being considered using phthalocyanine derivatives for phthalocyanine.

However, in these methods, a phthalocyanine derivative is added in order to obtain a phthalocyanine having properties as an optical semiconductor.9 For example, phthalocyanine derivatives are added to obtain ε-type copper phthalocyanine.

The optical semiconductor material according to the present invention can be used in one, for example, three-dimensional method. (A) A method in which an unstable or semi-unstable phthalocyanine and a phthalocyanine derivative are each synthesized or prepared in advance and mixed in the following manner.

(B) A method of synthesizing or preparing an unstable or semi-unstable phthalocyanine photosemiconductor in advance and synthesizing a phthalocyanine derivative in its presence; (C) A method of synthesizing an unstable or semi-unstable phthalocyanine photosemiconductor and a phthalocyanine derivative in the presence of the unstable or semi-unstable phthalocyanine photosemiconductor; However, the present invention is not limited to this method.

Next, an example of the mixing method is as follows: (1) An unstable or semi-unstable phthalocyanine photosemiconductor and a phthalocyanine derivative are uniformly mixed by mechanical milling using a known method. (2) An unstable or semi-unstable phthalocyanine optical semiconductor and a phthalocyanine derivative are mixed in a conventional mixing device 1, such as a tumbler for mixing powder. (3) Mix unstable or quasi-unstable phthalocyanine photosemiconductors and phthalocyanine derivatives with a suitable organic solvent such as xylene in a mixer. A quasi-unstable phthalocyanine photosemiconductor and a phthalocyanine derivative are added and dispersed using a device such as a ball mill or a sand mill. (5) The phthalocyanine derivative or the unstable or semi-unstable phthalocyanine photosemiconductor is simply added to the unstable or semi-unstable phthalocyanine photosemiconductor or the phthalocyanine derivative dispersed in the binder resin. It is.

The phthalocyanine of the unstable or semi-unstable phthalocyanine photosemiconductor according to the present invention is metal-free phthalocyanine or metal phthalocyanine.

Or a mixture of these. Metal phthalocyanine metals include copper, silver, beryllium, magnesium, calcium, zinc, cadmium, barium, mercury, aluminum, gallium, indium, lanthanum, neodymium, samarium, europium, gadolinium, dysprosium, holmium, sodium, lithium, and interbium. , lutetium, titanium tin, hafnium, lead, thorium, vanadium, antimony, chromium, molybdenum, uranium, manganese, iron, cobalt, nickel.

These include rhodium, palladium, osmium, and platinum. Moreover, instead of a metal atom, the central nucleus of the phthalocyanine may be a metal halide having a valence of 3 or more. Metal-free phthalocyanine, copper, cobalt, lead,
Metal phthalocyanines such as zinc are preferred. Furthermore, it may be a low halogenated phthalocyanine. Note that phthalocyanine is a compound well known as a pigment.

In the present invention, the phthalocyanine obtained by any manufacturing method may be used. Although phthalocyanine having various crystal forms is known, in the present invention, a phthalocyanine optical semiconductor having an unstable or semi-unstable crystal form is used. For example, α type, T type,
The crystal forms include δ type, ε type, and X type, but preferably α type or ε type. Furthermore, nitrated phthalocyanine,
An unstable or semi-unstable phthalocyanine as a mixed crystal of a derivative such as a sulfonated phthalocyanine and a phthalocyanine may also be used.

As the phthalocyanine derivative according to the present invention, any phthalocyanine derivative that stabilizes the crystal of the phthalocyanine optical semiconductor can be used.

Phthalocyanine derivatives are phthalonitrile, which is the raw material for phthalocyanine during phthalocyanine synthesis.

Phthalic acid, phthalic anhydride, phthalimide, etc. are synthesized using those whose benzene nucleus has a substituent. Alternatively, a substituent can be introduced by later modifying the phthalocyanine.

Examples of phthalocyanine derivatives include phthalocyanine derivatives represented by the following general formula.

(In the formula, Pc is a phthalocyanine residue, X is a halogen atom, a nitro group, an alkoxy group, a phenoxy group, and has a carbon number of 1 to
20 represents a substituent of a substituted or unsubstituted phenylcarbamoyl group or a phenylsulfamoyl group, Y is any substituent such as (a) to (f) shown below, and 1m is 0-2. n is O~4, and m + n
= indicates 1 to 6.

R+ and R each represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a heterocycle formed by R1 and R2 containing at least a nitrogen atom.

R3 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a nitro group.

6 / (c) C0NR4Ry N ゝ2□ R4 is a hydrogen atom, a substituted or unsubstituted alkyl group, R5
is a substituted or unsubstituted alkylene group or arylene group,
R6°R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or R6 and RrI form a heterocycle containing at least a nitrogen atom.

(d) SOJMI Ml represents an alkali metal or an alkaline earth metal.

R’l.

/ R8 is a hydrogen atom, a substituted or unsubstituted alkyl group, Rl
I is a substituted or unsubstituted alkylene group or arylene group, R1°;

R and l each represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a heterocycle formed by R, O and RlI containing at least a nitrogen atom.

(f) -000M2°Ml represents an alkali metal or an alkaline earth metal. ) The above-mentioned phthalocyanine derivatives are just one example, and the present invention is not limited thereto, and any derivative that stabilizes the particles of the phthalocyanine photoconductor can be used.

The phthalocyanine derivatives include metal-free phthalocyanine or copper, iron, cobalt, nickel, magnesium, and calcium.

Metal phthalocyanines such as sodium, lithium, and aluminum.

The composition ratio of the unstable or semi-unstable phthalocyanine photosemiconductor and the phthalocyanine derivative of the present invention is from o;oot to 40 parts by weight of the phthalocyanine derivative per 100 parts by weight of the phthalocyanine photosemiconductor. If it is less than 0.001 part by weight, sufficient non-aggregation or crystal stability will not be obtained, and sensitivity will also be poor. Also, if it exceeds 40 parts by weight,
The nl attenuation rate increases and it cannot be put to practical use.

The optical semiconductor material of the present invention only needs to be a mixture of an unstable or semi-unstable phthalocyanine optical semiconductor and a phthalocyanine derivative in a practically uniform state. The fact that the photosemiconductor material obtained by the above mixing method has excellent storage stability and that the electrophotographic photoreceptor obtained from this photosemiconductor material has good electrophotographic properties is that It is extremely advantageous in industry. Electrophotographic properties such as photosensitivity and stability of sensitivity due to repetition may vary depending on the type and amount of phthalocyanine derivatives, but with an appropriate combination, they can be on the same level as optical semiconductor materials such as cadmium sulfide. It is possible to obtain a photosensitivity, etc. of , and even higher light resistance.

The optical semiconductor material of the present invention may be used alone as it is to form a photosensitive layer together with a binder resin or the like. moreover.

Depending on the case, it is also possible to use other phthalocyanine-based optical semiconductor materials, other optical semiconductor materials 1, and ordinary sensitizers together. A photosensitive layer using a vapor deposition method may also be used.

In addition, the optical semiconductor material according to the present invention can be used in combination with compounds such as hydrazone, oxadiazole, triphenylmethane, pyrazolone, and di-styryl, which are known as charge transfer materials, in a single layer or in a stacked layer. It can also be used as a functionally separated type.

Furthermore, if necessary, 0.01 to 30 parts by weight of an antioxidant can be used in combination with 100 parts by weight of phthalocyanine.

In order to use the optical semiconductor material of the present invention as an electrophotographic photoreceptor, it is uniformly dispersed together with a binder resin, a solvent, etc. using a crosstalk dispersion machine such as a ball mill or attritor, and coated on a conductive support. Form a photosensitive layer. 2. In the electrophotographic photoreceptor using the optical semiconductor material of the present invention, it is needless to say that the electrophotographic photoreceptor has only a photosensitive layer according to the present invention, but it also has a barrier layer, an insulating layer,
It may also be an electrophotographic photoreceptor in which photosensitive layers of other optical semiconductor materials are laminated.

Binder resins include volume-specific resins such as melamine resin, epoxy resin, silicone resin, polyurethane resin, polyester resin, acrylic resin, xylene resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate resin, and cellulose derivatives. It is a binder resin having an insulating property with a resistance of 101 Ωcm or more.

This photosemiconductor material is applied by coating onto a sheet-like or cylindrical conductive support such as an aluminum plate, conductively treated paper, or plastic film, which is commonly used in electrophotographic photoreceptors, to form a photosensitive layer. As for the coating method, if necessary, add a solvent to the optical semiconductor material to adjust the viscosity, and use an air doctor coater, blade coater,
Film formation is performed using a coating method such as a ronto coater, reverse roll coater, spray coater, real coater, or spray coater. After coating, appropriate drying is performed until a sufficient charging potential is applied as a photoconductive layer.

Further, the photoreceptor according to the present invention usually has a resin/photoconductor element weight ratio of 1 or more, and has a larger amount of resin than, for example, a photoreceptor using zinc Mide.

The coating has physical strength and is highly flexible. It also has a high adhesive strength with the conductive support and good moisture resistance. There is little change over time and there are no toxicity problems.

It has excellent practical characteristics such as being easy to manufacture and inexpensive.

3. When using the electrophotographic photoreceptor using the optical semiconductor material of the present invention, the light source may be a halogen lamp or the like, or a laser beam may be used.

In the above invention, the electrophotographic photoreceptor has been mainly explained, but the optical semiconductor material of the present invention can also be used for other purposes.

For example, it can also be used for solar cells, sensors, etc.

The present invention will be explained below by giving one example. In the examples, "parts" indicate parts by weight.

Example 1 ε-type copper phthalocyanine 1 part 2,5-bis(4-diethylaminophenyl)-1,3
, 4-oxadiazole 3 parts Piperidinomethyl steel phthalocyanine o, 01 parts Acrylic polyol (Takerank A-7 manufactured by Narita Pharmaceutical Co., Ltd.)
02) 3.6 parts epoxy resin (Epon 1007 manufactured by Shell Chemical Co., Ltd.) 0.5
1 part xylene 1.2 parts cellosolve acetate 1.2 parts The above composition was kneaded in a magnetic ball mill for 48 hours to obtain a photoconductive composition.

Immediately after manufacturing the resulting photoconductive composition, after one month, 3
After several months, images with excellent storage stability were obtained.

Comparative Example 1 A photoconductive composition was made without using the phthalocyanine derivative in the photoconductive composition of Example 1.

When tested in the same manner as in Example 1, it was found that immediately after production, it was slightly inferior compared to immediately after production in Example 1, and there was no significant difference compared to Example 1, but after one month, aggregation of phthalocyanine was observed. , a crystal transition to the β type was observed, and the sensitivity was 20.
It became Lux -5ec.

Examples 2 to 3 The ε-type copper phthalocyanine and phthalocyanine derivative of Example 1 were replaced with the phthalocyanine and phthalocyanine derivative shown in the table below to prepare an electrophotographic photoreceptor, and the maximum surface charge amount, dark decay rate, sensitivity, and residual potential were determined in the same manner. was measured.

(Cupc and NiPc represent copper and nickel phthalocyanine residues, and the numbers outside parentheses indicate the average number of substitutions determined by analysis.) Example 5 40 parts of copper phthalocyanine and 0.5 parts of tetranitrocopper phthalocyanine were added to 500 parts of 98% concentrated sulfuric acid. Dissolve while stirring thoroughly. The dissolved solution is poured into 5000 parts of water to precipitate a V7 talocyanine composition, which is then filtered, washed with water, and dried at 120° C. under reduced pressure. X-ray diffraction analysis of the resulting composition revealed that it had an α-type crystal structure.

Next, 1 part of this composition, P=N-diethylaminobenzaldehyde-N,N-diphenylhydrazone 2.591
Piperidinosulfonamide copper phthalocyanine part, Takelac A-7023° 6 parts, Epon 1007 0.5
When a photoelectric composition was prepared from a composition consisting of 1.2 parts of methyl ethyl ketone and 1.2 parts of cellosolve acetate in the same manner as in Example 1, no change was observed even after 3 months had passed. As an electrophotographic photoreceptor, the maximum surface charge amount is 620 V, the dark decay rate is 4.6%, and the sensitivity is 1.9.
Luxsec+residual potential was 40V, and good results were obtained.

Comparative Example 2 A photoconductive composition was made without using the phthalocyanine derivative in the photoconductive composition of Example 5.

When tested in the same manner as in Example 5, there was almost no change immediately after production, but after 3 months, aggregation of phthalocyanine was observed, crystal transition to the β type was observed, and the sensitivity was 18 Lu.
x-see, and the sensitivity is about 1/18, which cannot be said to be of practical use.

Examples 6 to 7 The phthalocyanine and phthalocyanine derivative of Example 5 were replaced with the phthalocyanine and phthalocyanine derivative shown in the table below to prepare electrophotographic photoreceptors, and the maximum surface charge amount, III attenuation rate, sensitivity, and residual potential were measured in the same manner. .

The results are shown after 3 months.

Example 8 A composition consisting of 10 parts of ε-type copper phthalocyanine, 0.1 part of piperidinosulfonamide copper phthalocyanine, 2 parts of polyester resin (Vylon RV-200 manufactured by Toyobo Co., Ltd.), 40 parts of tetrahydrofuran, and 10 parts of toluene was prepared in Example 1.
A charge generation layer was formed by coating in a thickness of 0.5 μm in substantially the same manner as above.

Next, a mixed solution of 10 parts of Vylon RV-200, 10 parts of N-ethylcarbazole-3-carbaldehydemethylphenylhydrazone, and 50 parts of tetrahydrofuran was applied to the charge generation layer to a thickness of about 10μ, and dried at 80°C. , a laminated photoreceptor was obtained.

When the electrophotographic properties of the obtained photoreceptor were investigated in an environment with a temperature of 0°C to 45°C and a humidity of 10% to 85%, the maximum surface charge amount was 1200, the soil was 100V, and the dark decay rate was 1.
, 5%, sensitivity of 3.6±0.5 Luxsec, and residual potential of 80 V, which showed little change and was sufficiently durable for practical use.

patent applicant Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] 1. An optical semiconductor material comprising an unstable or semi-unstable phthalocyanine optical semiconductor and a phthalocyanine derivative that stabilizes crystals of the phthalocyanine against organic solvents. 2. The optical semiconductor material according to claim 1, wherein the unstable or semi-unstable phthalocyanine optical semiconductor is a phthalocyanine having one type of crystal form selected from α-type and ε-type.