JPS6093443A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitiv body easily preparable and comparatively low in cost and superior in durability by incorporating a specified thiophene compd. in a photosensitive layer. CONSTITUTION:An electrophotographic sensitive body contains as an effective photoconductor a thiophene compd. represented by general formula ( I ) in which Ar is optionally substd. phenyl or styryl; R1 is H, lower alkyl, or optionally substd. phenyl; and R2, R3 are each lower alkyl, aralky, or optionally substd. phenyl. A superior electrophotographic sensitive body is obtained by forming a photosensitive layer 2 contg. the thiophene compd., a sensitizing dye, and a binder on a conductive substrate 1, or forming on the conductive substrate 1 a photosensitive layer 2' obtained by dispersing an electrostatic charge generating material 3 into a charge transfer medium 4 contg. the thiophene compd. and the binder.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a specific thiophene compound in its photosensitive layer.

Prior Art Conventionally, inorganic materials such as selenium, carded cadmium, and zinc oxide have been used as photoconductive materials for photoreceptors used in electrophotography. The term "electrophotography" as used herein generally refers to a method in which a photoconductive photoreceptor is first charged locally, for example, with corona discharge, and then imagewise exposed to selectively remove the charge only in the exposed areas. This latent image is dispersed to obtain an electrostatic latent image, and this latent image is transformed into electrostatic fine particles (toner) consisting of a coloring agent such as a dye or pigment and a binder such as a polymeric substance.
Visualize the current state and r i! This is one of the image forming methods in which 1k images are formed.

The basic characteristics required of the photoreceptor in such electrophotographic methods are 1) ability to be charged to an appropriate potential in a dark place, 2) less dissipation of charge at n locations, and 3)
Examples include scales that quickly dissipate charge when irradiated with light.

Incidentally, it is a fact that each of the above-mentioned inorganic substances has many advantages, but also has various disadvantages. For example, selenium, which is currently widely used, fully satisfies the above conditions (3) to 3), but the manufacturing conditions are difficult, the manufacturing cost is high, it is not flexible, and it cannot be processed into a belt shape. Difficult, thermal or mechanical! ! 1511! It also has some drawbacks, such as being sensitive to chemicals and requiring careful handling. Cadmium sulfide and zinc oxide are used as photoreceptors by being dispersed in resin as a binder, but they have mechanical drawbacks such as smoothness, hardness, tensile strength, and abrasion resistance, so they cannot be used as is. and cannot be used.

In recent years, in order to eliminate the drawbacks of these inorganic materials, electrophotographic photoreceptors using various organic materials have been proposed and put into practical use. .4.7-Trinide Ofluorene-9-one (U.S. Pat. No. 3,484,237)
(described in the specification), a photoreceptor made by sensitizing poly-N-vinylcarbazole with a biryllium salt dye (Japanese Patent Publication No. 1973-
25658), a photoreceptor whose main component is an organic pigment (described in JP-A-47-37543), a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (JP-A-47-37543) -10735@described in the official publication). Although these photoreceptors have excellent 7e characteristics and are considered to be of high practical value, considering the various requirements for photoreceptors in electrophotography, it is still difficult to meet these requirements. The reality is that we have not been able to obtain anything that is fully satisfactory.

However, the photoreceptors mentioned so far (1) differ depending on the purpose or manufacturing method, but generally speaking, good characteristics can be obtained by using an excellent photoconductive material. It is something that can be done.

Purpose An object of the present invention is to eliminate the various drawbacks of the conventional photoreceptors mentioned above and to provide a photoreceptor that satisfies the J3 requirements of electrophotography. . The object of the present invention is to be easy to manufacture and relatively inexpensive;
An object of the present invention is to provide an electrophotographic photoreceptor having excellent durability.

Structure As a result of research and consideration on many photoconductive substances, the present inventor found the following general formula () (where Ar is a substituted or unsubstituted phenyl group, a substituted or unsubstituted styryl group, R + is hydrogen, a lower alkyl group, or a substituted or unsubstituted phenyl group, 1
(2 and R3 represent a lower alkyl group, an aralkyl group, or a substituted or unsubstituted phenyl group.) The diophene compound represented by the following formula is effective as a photoconductive substance for electrophotographic photoreceptors. I discovered that.

Examples of substituents on the phenyl group in A or R+ of the above general formula include alkyl groups such as methyl, ethyl, propyl, butyl, methoxy, ethoxy,
Alkoxy groups such as -oxy, benzyloxy groups, halogen atoms such as chlorine and bromine, etc.
2 Jj J, and I (in 3) -C is a substituent of a nyl group such as methyl, ethyl, propyl, butyl, methoxy, I-oxy, D-boxy, 7
Alkoxy groups such as 1-oxy, thioalkoxy groups such as methoxy and thioethoxy, thiophenyl groups, chlorine,
Halogen atoms such as bromine, dialkylamino groups such as dimethylamino, diethylamino, diprogylamino, N-methyl-N-ethylamino, hydroxy groups, carboxyl groups and their esters, acyl groups, aryl groups such as phenoxy, benzyloxy, etc. Examples include aralkyloxy, trifluoromethyl, nitro, and cyano groups.

As will be clear from the description below, this thiophene compound can be used in combination with various materials to advance JIJ.
We have also created a photoreceptor that has a similar effect and found that it has scales. The present invention was completed based on these findings.

That is, the present invention provides an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive support, in which the photosensitive layer has the above general formula (I
) is characterized by containing a thiophene compound represented by:

The thiophene compound represented by the general formula S(I>) used in the present invention is represented by the following general formula (1) (wherein A', R
I is the same as general formula (I), YLt P ” 63 Z
A triphenylphosphonium group or -PO(OR)2(
Here, R represents a lower alkyl group). ) and an aldehyde compound represented by the following general formula (11) (wherein R2 and R3 are the same as in general formula (I)).

The phenyl derivative represented by general formula (II) can be obtained by heating the corresponding halomethyl compound and trialkyl phosphite or triphenylphosphine directly or in a solvent such as toluene, tetrahydrofuran, N,N-dimethylformamide, etc. Easily manufactured. Here, the phosphorus m+-realkyl is preferably an alkyl group having 1 to 4 carbon atoms, particularly a methyl group or an ethyl group.

The phenyl derivative represented by the general formula (IN) thus obtained and the aldehyde compound represented by the general formula (DI) are reacted at a temperature ranging from air temperature to about 100° C. in the presence of an IJAM medium.

Basic catalysts include caustic soda, caustic potash, sodium amide sodium hydride and strium methylate;
Potassium-1-butokiri.

I can list an alcorado with an id k. Also,
Reaction solvents include methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2
- Tsume 1 ~ xyethane, bis(2-methoxyethyl) ether, dioxane, tetrahydrofuran, toluene,
Examples include xylene, dimethyl sulfoxide, N,N-dimethylformamide, N-methylbiolidone, and 1,3-dimethyl-2-imidazolidinone. Among these, polar solvents such as N 2 , N-dimethylformamide and dimethyl sulfoxide are preferred.

The reaction humidity depends on 1) the stability of the solvent used with respect to the monobasic catalyst, 2) the reactivity of the condensation components (compounds of general formulas (11) and (1)), and 3) the condensation in the basic catalyst. They can be selected from a wide range depending on their reactivity as agents. For example, when using a polar solvent, the actual temperature range is from air temperature to 100°C.
, preferably from room temperature to 80°C. However, higher temperatures may be used if the reaction time is shortened or a less active condensing agent is used.

An example of the production is as follows, without specifically showing it.

¥J Preparation Example 1 1.1-Diedyl Schiff]ylmethylphosphonate 30.4
11 (0.1 mol) and 30.7 g (0.1 mol) of 2-N,N-di1helylamino-5-diA phenaldehyde were dissolved in 1001 of N,N-dimethylbormamide, and potassium-t -butoxide 10.80 (0
, 15 mol) at 25-35°C. After stirring at room temperature for 6 hours after the addition, the reaction mixture was diluted with water 2001. The precipitated powder was filtered, washed with water, and dried to obtain a pale yellow powder. The yield is 42. Ia (92%), melting point is 1
Recrystallization was performed from a mixed solvent of ethyl acetate and ethanol at a temperature of 55.5 to 157.0°C to obtain a pure product of 2-N,N-ditolylamino-5-(β-phenylstyryl)thiophene. The melting point was 157.0-158.0°C.

Specific examples of the thiophene compound represented by the general formula (I>) obtained in this way are shown in Figure 1 below.

Table-1 H3 C1-13 CH3 30o-20=CHnN (@>2 31 (@)-20=C1leNsha0l-h) 23
2 (O>-20=CH[N(GOCI-1 mountain 36 <
4〉〉-〇H=CH-CI-1=cI-IJC ■Second x
6) 737 ecl-I=CH-CI-! =CH6N
eC1-L+) 2 The photoreceptor of the present invention contains one or more of the above-mentioned thiophene compounds in the photosensitive layer. It can be used as shown in FIG.

The photoreceptor shown in FIG. 1 has a photosensitive layer 2 made of a thiophene compound, a sensitizer, and a binder (binder resin) on a conductive support 1. Thiophene compounds act as photoconductive substances, and the generation and transfer of electromagnetic carriers necessary for light attenuation occur through thiophene compounds.However, thiophene compounds have almost no absorption in the visible region of light43. Therefore, for the purpose of forming an image with isotropic light, it is necessary to sensitize it by adding a sensitizing dye that absorbs in the visible region.

The photoreceptor shown in 1) in FIG. 2 has a photosensitive layer 2' in which a charge generating substance 3 is dispersed in an image carrying medium 4 made of a thiophene compound and a binder on a conductive support 1. It is something that

The thiophene compound here together with the binder (or binder and plasticizer) forms the charge transport medium 4, while the charge generating substance 3 (a charge generating substance such as an inorganic or organic pigment) generates the charge carriers. In this case, the charge transport medium 4 mainly receives charge carriers generated by the charge generator 'f43,
It is responsible for transporting this.

In this photoreceptor, the basic condition is that the C absorption wavelength regions of the charge generating substance and the thiophene compound do not overlap each other, mainly in the visible region. This is because in order to efficiently generate rB carriers in the charge generating substance 3, it is necessary to transmit light to the surface of the IJi generating substance. The thiophene compound represented by the general formula (1) has almost no absorption in the visible region, and generally absorbs light in the visible region and is particularly effective at transporting charges when combined with an IR generating substance 3 that generates charge carriers. Its characteristic is that it works as a substance.

The photoreceptor shown in FIG. 3 has a photosensitive layer 2'' formed on a conductive support 1, which is a lamination of a charge generation layer 5 mainly composed of a charge generation substance 3 and a charge transport layer 4 containing a thiophene compound. In this photoreceptor, light transmitted through the charge transport layer 4 reaches the charge generation layer 5, and generation of charge carriers occurs in that region. It receives carrier injection and transports it. Generation of charge carriers necessary for optical attenuation is performed by charge generation material 3, and charge carrier transport is carried out by charge transport layer 4 (mainly C
The process is carried out using a thiophene compound. Such a mechanism is similar to the explanation given by C and nil in the photoreceptor shown in FIG.

In order to actually produce the photoreceptor of the present invention, in the case of the photoreceptor shown in FIG. 1, one or more thiophene compounds are dissolved in a solution containing a binder, and a sensitizing agent The I photosensitive layer 2 can be formed by preparing a liquid containing the above ingredients, applying it to the conductive support 11, and drying it.

The thickness of the photosensitive layer 2 is 3 to 50 μm, preferably 5 to 20 μm.
Ugliness is appropriate. m of the thiophene compound in the photosensitive layer 2 is 30 to 10% by weight, preferably about 50% by weight,
Further, the proportion of the sensitizing dye in the photosensitive H2 is 0.1 to 5% by weight, preferably 0.5 to 3% by weight. As an infection charge, Brilliant 1~Green, Victory)! blue 1
3. Methyl Violet 1-, Crystal Violet,
Triarylmethane dyes such as Acid Violet 6B, Rhodamine B, Rhodamine GG, Rhodamine G Extra, Eosin S11 Litrosine, Rose Bengal, Xanthene dyes such as Fluorescein, Thiazine dyes such as Methylene Blue, Cyanine dyes such as Cyanine, 2 Examples include biryllium dyes such as 6-diphenyl-4-(N,N-dimethylaminophenyl)thiapyrylium verchlorate and benzopyrylium m (described in the publication 11G 4B-25658-@). In addition, these l! 1m dye n may be used alone or two or more types may be used for Ut1.

In addition, in order to produce the photoreceptor shown in FIG. 2, fine particles of the charge generating substance 3 are dispersed in a solution containing one or more thiophene compounds and a binder, and the fine particles are dispersed on a conductive support. 1 and dried to form a photosensitive layer 2'.

The thickness of the photosensitive layer 2- is 3 to 50 μm, preferably 5 to 2 μm.
0 μm is appropriate. The proportion of the thiophene compound in the photosensitive layer 2- is 10 to 15% by weight, preferably 30 to 90% by weight, and the m content of the charge generating substance 3 in the photosensitive layer 2 is 0.1 to 50% by weight. Preferably 1~
It is 20% by weight.

Charge 5t! [Substance 3 is, for example, Relen, Selenium-
Tellurium, cadmium sulfide, cadmium sulfide, α
- Inorganic pigments such as silicone, mmI pigments such as C.I. Bigmen 1 to Blue-25 (color index CI 21180), C.I. Pigment Red 41
(CI 21200>, Sea Eye Acid Red 52
(CI 4!1100), CI Basic Red 3
(CI 45210) Azo pigment having a carbazole skeleton (described in JP-A-53-95033), azo pigment having a distyrylbenine skeleton (JP-A-53-13)
3445), azos Fl having a triphenylamine skeleton (described in JP-A-53-132347), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), Azo pigments having a xadiazole skeleton (described in JP-A No. 54-12742), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a his-dirubene skeleton (described in JP-A-54-22834), Azo pigments having a distyryl oxadiazole skeleton (described in Special Publication No. 1f11 Sho 54-2129), azo pigments having a distyryl oxadiazole skeleton, such as C.I. Bigmen 1- Phthalocyanino-based M materials such as Blue 16 (CI-74100),
Azo pigments such as C.I. Butt Brown 5 (c173410), indigo pigments such as C.I.Bara 1-Dye (CI 73030), Argo Scarlet 1-B (Bayer Ceremony), Indus Thread Scarlet 1 Examples include perylene pigments such as -R (Bayer!!J). Note that these charge generating substances may be used alone or in combination of two or more.

Furthermore, make the photoreceptor shown in Figure 3! II! To do this, the charge generating substance 3 is vacuum-deposited on the conductive support 11, or fine particles of the charge generating substance 3 are dissolved in a binder if necessary. After coating, drying and rinsing, if necessary, polish the surface by a method such as puff polishing. i) vII
A TN generation layer 5 is formed, and a solution containing one or more bu-A phen compounds and a binder dissolved therein is applied 15 and dried to form a charge transport layer. All you have to do is form 4. The charge generating material 3 used to form the charge layer 5 is the same as that used in the description of the photosensitive layer 2-b above.

The thickness of the charge generation layer 5 is preferably 5 .mu.m or less, preferably 2 .mu.m or less, and the thickness of the charge transport layer 4 is suitably 3 to 50 .mu.m, preferably 5 to 20 .mu.m. When the charge generation layer 5 is of a type in which fine particles of the charge generation substance 3 are dispersed in a binder, the proportion of the fine particles of the charge generation substance 3 in the charge generation layer 5 is preferably 10 to 95% by weight. is about 50 to 90% by weight. Further, m of the thiophene compound in the charge transport layer 4 is 10 to 95% by weight, preferably 30 to 90% by weight.

In the production of these photoreceptors, the conductive support 1 is made of a metal plate or metal foil such as aluminum, a plastic film coated with a metal such as aluminum, or
Paper that has been subjected to conductive treatment is used. [As a binder, polyamide, polyurethane, polyester,
Condensation resins such as epoxy resin, polycarbonate, and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, polyN-vinyl rubber, and polyacrylamide are used, but resins that are insulating and adhesive are used. can all be used. If necessary, a plasticizer is added to the binder, and examples of the IC plasticizer include halogenated paraffin, polychlorinated piphenyl, dimedylnaphthalene, and dibdelphthalate.

Furthermore, for the above J: sea urchin photoreceptor, an [adhesive layer or burr 17 layer may be added between the conductive support and the photosensitive layer, if necessary. You can shiv. Materials used for these layers include polyamide, nitrocellulose, aluminum oxide, etc., and the film thickness (preferably 1 μm or less).

In order to make a copy using the photoreceptor of the present invention, the photoreceptor surface is charged and exposed, a phenomenon is performed, and if necessary, the image is transferred to paper or the like.

The photoreceptor of the present invention has excellent advantages such as high sensitivity and high flexibility.

Examples are shown below. In the examples below, J3 is the total weight of J3.

Example 1 On the charge generation layer, 76 parts of Diane Blue (CI Pigment Blue 25, CI 21180) and 2 parts of polynisder resin (Bi[1-200, manufactured by Toyobo Co., Ltd.) were added.
% tetrahydrone furan solution and 3100 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was applied onto the aluminum surface of a conductive support made of an aluminum-deposited polyester base using a doctor blade. A charge generation layer having a thickness of about 1 μm was formed by air drying.

On the other hand, as a charge transport material, 2 parts of N001 thiophene compound, polycarbonate resin (1300% for Panlite,
After mixing and dissolving 2 parts (manufactured by Mitsuyuri Co., Ltd.) and 16 parts of tetrahydrofuran to form a solution, this was applied onto the charge generation layer using a doctor blade and heated at 80°C for 2 minutes.
11. Next, dry at 105℃ for 5 minutes to a thickness of about 20μm.
A photoreceptor N091 was prepared by forming a charge transport layer.

Examples 2 to 16 Densen outbreak! ll! Photoreceptors Nos. 12 to 1G were prepared in the same manner as in Example 1, except that the material and the charge transport material (thiophene compound) were replaced with the materials shown in Table 2.

Table 2 Example 17 On an aluminum plate having a thickness of about 300 μm, selenium was vacuum-deposited to a thickness of about 1 μm to form a charge generation layer. Next, 2 parts of No. 38 Dioff-1 compound, polyester resin (Polyester Adhesive 49000 manufactured by DuPont)
) and 45 parts of tetrahydrofuran were mixed and dissolved to prepare a charge transport layer forming liquid, and this was applied onto the above charge generation 1IIi (I? rylene adhesion layer) using a doctor blade, and after air drying, A charge transport layer having a thickness of about 10 μm was formed by drying under reduced pressure to obtain photoreceptor No. 17 of the present invention.

Example 18 A charge generation layer was formed using a perylene pigment instead of selenium (however, the thickness was approximately 0.3 μι), and a thiophene compound was used in No.

Photoreceptor No. 18 was prepared in exactly the same manner as in Example 17, except that photoreceptor No. 22 was used instead of photoreceptor No. 38.

Example 19 A mixture of 1 part of Diane Blue (same as the IC used in Example 1) and 158 parts of Te] Rahid O furan was ground and mixed in a ball mill, and then thiophene compound No. 12 was added to the mixture. A photosensitive layer forming solution obtained by adding 18 parts of polyester resin (Polyester Adhesive 49000 manufactured by DuPont) and further mixing was applied onto an aluminum vapor-deposited polyester film using a doctor blade, and heated at 100°C for 30 minutes. Approximately 16 μm thick after drying for minutes
photoreceptor No. 19 of the present invention was prepared by forming a photoreceptor layer of /j 0 Photoreceptor No. 19 thus prepared
9, using a commercially available electrostatic copying paper tester (model 5P428 manufactured by KK Kawahi Nichi Denki Seisakusho)
After charging by corona discharge for 20 seconds, 20
The surface potential VIIO (Pol 1
~), then irradiate the photoreceptor surface with tungsten lamp light so that the trace becomes 4.5 lux, measure the time (seconds) until the surface potential becomes 1/2 of vpO, and then apply the exposure IRE. 1/2 (lux/second) was extracted and the results are shown in Table 3.J0 Also, Shun produced each of the above photoreceptors using a commercially available electrophotographic copying machine, and irradiated light through the original image. was carried out to form an electrostatic latent image, which was developed using a dry developer, and the resulting image (11 (+-toner image) was electrostatically transferred onto plain paper and fixed (1 = clear transfer). An image was obtained.A similarly clear transferred image was obtained when a wet type image forming agent was used as the developer.

Table 3 Effects As stated above, the photoreceptor of the present invention has the general formula (I
) By using the thiophene compound shown in the formula, it is possible to fully satisfy the conditions required for a photoreceptor and form a clear image.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views enlarged in the thickness direction of an electrophotographic photoreceptor according to the present invention. 1... Conductive support 2.2-2 2"... Photosensitive layer 3... Charge generating material 4... Charge transporting medium or charge transporting layer 5... Charge generating layer layer 1"... Charge generating layer 20 November 11, 1980 Director-General of the Patent Office Kazuo Wakasugi 1. Display of matter f. Patent application filed on October 28, 1980 22. Name of the invention Electrophotographic photoreceptor 3 , the relationship between tenancy and the like to be amended Special R7 [Applicant name (674) Ricoh Co., Ltd. - Name (78
99) Patent attorney Hidetake Komatsu (and one other person) 5. Amendment order date 1 (voluntary) 6. Subject of amendment 11111, column 7 for claims and detailed description of the invention, contents of amendment Attachment Noto 43S (Attachment) (1) The scope of the claims from the 4th line on page 1 is as follows: iJ' +E-! I. [2. Claims (1) A photosensitive layer containing, as an active ingredient, at least t) one bu Δfurin compound represented by the following general formula (1) on a conductive support. An electrophotographic photoreceptor characterized by having the following. (in the formula, r is a replacement or a replacement) to a R group, or V! ground or unsubstituted sudyryl group, R1 is hydrogen,
Lower alkyl group or substituted or unsubstituted phenyl group, R2 and R3 are lower alkyl group, aralkyl group, direct substituted or unsubstituted phenyl group Table (2) Page 6, lines 3 to 4 "・...As a substituent on the phenyl group"
[...63L to the substituent on the phenyl group or Ar
) as a substituent on the benzene ring of the Subouril base. [Correct the left side of the 6th compound on page 12 of 31 as "[".

Claims (1)

[Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing at least one thiophine compound represented by the following general formula (I) as an active ingredient on a conductive support. (In the formula, A is a substituted or unsubstituted phenyl group, or a substituted or unsubstituted styryl group, R1 is hydrogen, a lower alkyl group, or an N-substituted or unsubstituted phenyl group, R
2d3 and 3 represent a lower alkyl group, an aralkyl group, or a substituted or unsubstituted phenyl group. )