CN1056453C - Method for prepn. of broadband response organic photoelectric conductor - Google Patents

Abstract

The invention discloses a method for preparing an organic photoconductor with a wide frequency response, which uses an azo-phthalocyanine blend compound as a carrier photogenerated material, a hydrazone carrier transport material, polycarbonate resin and suitable The solvent is matched to form a stable organic photoconductive material dispersion system, and a single-layer organic photoconductor with a wide frequency response is prepared by dip coating; the composite photogenerated material can also be used with polyvinyl butyral resin and hydrazone carrier transport The materials are matched, and a double-layer organic photoconductor with a wide frequency response is prepared by a dip-coating method. The performance test results show that no matter the single-layer organic photoconductor or the double-layer organic photoconductor has excellent photoconductivity in the range of visible light to near-infrared light.

Description

A kind of method for preparing broadband response organic photoelectric conductor

The present invention relates to the preparation method of organic high molecular compound, relate in particular to a kind of method for preparing organic photoconductor.

Organic photoconductor is meant under the effect of light; can cause a class hi-tech device of the formation and the migration of photo-generated carrier; be widely used in Xerox based on electric photographic technology; laser printer; " the heart "-photosensitive drums of equipment such as laser facsimile; become a huge high-tech industry abroad; huge economic benefit and social benefit have been obtained; and reduced environmental pollution; be subjected to the attention of each developed country of the world; Japan; the U.S.; all apply for a patent one after another in West Europe etc.; protect the intellecture property of oneself, what have has also applied for patent in China.Domestic research to organic photoconductor though be started in early sixties in this century, was just interrupted for two more than ten years immediately, just recovered research mid-term to the eighties, though obtain breakthrough technically, the industrialization of still being unrealized so far at present.Required organic photoelectric conducting drum on the home market, whole dependence on import, the annual foreign exchange that needs tens million of dollars of costs, and also the demand of home market is also in rapid rising.Simultaneously, realizing the production domesticization of organic photoelectric conducting drum, also is the key of home-made equipments such as Xerox, laser printer, laser facsimile.

The structure of organic photoconductor, the branch that single layer structure and double-decker are arranged, the charge carrier photoproduction function of single layer structure organic photoconductor and carrier transport function are by serving as with a kind of material or compound, on a conducting base, this material or compound coated on it, can obtain the single-organic photoconductive body, because the photosensitivity and the life-span of such material or compound are all lower, the organic photoconductor of single layer structure is almost completely superseded.At present popular in the world is the double-layer photoelectric conductor of function divergence type, be that the photoproduction function of charge carrier and the transfer function of charge carrier are to be served as by two kinds of different materials respectively, on a conducting base, elder generation coated restraining barrier, be coated with charge carrier photoproduction layer, coated carrier blocking layers then again, form a complete double-deck organic photoconductor, wherein charge carrier photoproduction layer is the core of organic photoconductor.

Azo compound (I) again with the big ring conjugation of the aromatic series that links to each other, reduces the energy between its valence band and the conduction band owing to have-the N=N-Multiple Bonds in the molecule, and (the light frequency responding range is 7.5 * 10 generally to drop on visible wavelength range 400～650nm ¹⁴～4.61 * 10 ¹⁴Hertz), has very high photosensitivity and stability at visible region, be desirable be the photoconductive material that the xerox of light source is used with the visible light, the external at present Xerox organic photoelectric conducting drum of producing is exactly to adopt the photoproduction material of azo compound as charge carrier mostly.And phthalocyanine-like compound (II), TiOPc especially wherein (TiOPc) and ranadylic phthalocyanine (VOPc), because its whole molecule is a big pi-conjugated system, making it is that (the light frequency responding range is 4.28 * 10 to 700～850nm in the near-infrared wavelength scope ¹⁴～3.53 * 10 ¹⁴Hertz) very high photosensitivity and stability are arranged, be desirable be the photoconductive material that the laser printing of light source is used with the near-infrared laser, the external at present laser printer organic photo conductor drum of producing adopts TiOPc (TiOPc) or ranadylic phthalocyanine (VOPc) the photoproduction material as charge carrier mostly.Because the spectral response range difference of this two classes material, being used for xerographi azo class photoconductor can not be as the photoconductor of laser printing; Equally, be used for the photoconductor of laser printing, can not be therefore as xerographi photoconductor, present manufacturer must adopt different photoconductive materials to produce different photoconductors according to different requirements.

For the standardization of organic photoconductor product, simplify production technology, improve the quality, reduce cost; Simultaneously, also in order to satisfy digitizing, the needs of intelligent copy system development, must produce a kind of is that (the light frequency responding range is 7.5 * 10 to 400～1000nm at visible light to the near-infrared wavelength scope ¹⁴～3.3 * 10 ¹⁴Hertz) have that superior wideband rings, the organic photoconductor of high stability.

Relevant organic complex light conducting material, be the Chinese invention patent (patent No.: 88100213.5) adopt the binary blended complex of phthalocyanine-like compound the earliest as charge carrier photoproduction layer material, improved the photosensitivity of phthalocyanines photoconductive material significantly, wideband rings and the problem of individual layer photoconductor but do not relate to as yet; Until 1993, Japanese patent laid-open 5-72774, employing coated one deck azo-compound again on the charge carrier photoproduction layer of TiOPc, with the charge carrier photoproduction layer of this double-decker, find that such organic photoconductor has wideband at visible region to near-infrared region and rings performance as double-deck organic photoconductor.Because this patent thinks that there are polarity difference in TiOPc and azo-compound, cause aggegation easily and sedimentation, more since mate the difference of solvent, caused the crystal formation conversion, and be difficult to form stable organic compound charge carrier photoproduction material, thereby can not get from the visible region to the near-infrared region that (400～800nm) have the single charge carrier photoproduction compound substance that wideband rings, can only adopt above-mentioned on TiOPc charge carrier photoproduction layer, coated one deck azo-compound again, the charge carrier photoproduction layer that rings as wideband with this double-decker.Obviously, described organic photoconductor of this patent and preparation method thereof, technology is more numerous and diverse, and photoconductive structure is reasonable inadequately, has reduced photoconductive efficient, does not more relate to the problem of individual layer photoconductor.Similarly also have Japanese patent laid-open 5-11469 (1993) to adopt TiOPc and ranadylic phthalocyanine to form mixed crystal earlier with this patent, coated is on conducting base, and then coated one deck azo-compound, be still with the charge carrier photoproduction layer of this double-decker as double-deck organic photoconductor; Japanese patent laid-open 5-40352 (1993) adopts the charge carrier photoproduction layer of the double-decker of bis-azo compound and three azo-compound as double-deck organic photoconductor; United States Patent (USP) U.S.Pat, the photoproduction layer of the blended complex of bis-azo compound and square acid compounds as double-deck organic photoconductor adopted in 5,270,139 (1993); Also has Jap.P. JP08 76,482,[96 76,782] double-decker of the bis-azo compound of employing phthalocyanine and sulfur-bearing, nitrogen is as the charge carrier photoproduction layer of double-deck organic photoelectric conducting drum, above-mentioned patent is all found to have wideband and is rung performance from the visible region to the near-infrared region, but all has same problem.Established technology is more numerous and diverse, and photoconductor structure is unreasonable, has reduced photoconductive efficient, does not more relate to the problem of single-organic photoconductive body.

(400～1000nm) have the method for the organic photoconductor of superior wideband sound, high stability near infrared range at visible light to the purpose of this invention is to provide a kind of preparation.

The present invention takes following measures in order to achieve the above object:

A kind of method for preparing broadband response organic photoelectric conductor, feature is:

A. at first, at normal temperatures, with azo-compound (I) that purifying is good and the phthalocyanine-like compound (II) that purifying is good, (I): weight ratio (II) is 8: 2～2: 8, in the presence of cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solvent, sand milling 0.5～1.5 hour, making mean grain size is the compound charge carrier photoproduction of the azo-phthalocyanine material (I-II) of 0.10～0.25 μ m;

B. then, (I-II) be transferred in the cyclohexanone that contains hydrazone class carrier transmission material (III) and polycarbonate (IV) or tetrahydrofuran or the chlorohydrocarbon solution wrap up, make stable organic composite photoelectric and lead the dispersion of materials system.(I-II): (III): weight ratio (IV) is 1: 10～20: 5～20.At last, should lead the direct coated of dispersion of materials system on conducting base by organic composite photoelectric with dip coating, dried coating thickness is 20～35 μ m, and having made the light frequency responding range is 7.5 * 10 ¹⁴～3.3 * 10 ¹⁴The single-organic photoconductive body of hertz.

R ₂-N＝N-R ₁-N＝N-R ₂ (I)

The another kind of method for preparing broadband response organic photoelectric conductor, feature is:

A. at first, at normal temperatures, with azo-compound (I) that purifying is good and the phthalocyanine-like compound (II) that purifying is good, (I): weight ratio (II) is 8: 2～2: 8, in the presence of cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solvent, sand milling 0.5～1.5 hour, making mean grain size is the compound charge carrier photoproduction of the azo-phthalocyanine material (I-II) of 0.10～0.25 μ m;

C. then, (I-II) be transferred in the cyclohexanone that contains polyvinyl butyral resin (V) or tetrahydrofuran or the chlorohydrocarbon solution wrap up (I-II): weight ratio (V) is 1: 0.5～2.0, makes the compound charge carrier photoproduction of stable azo-phthalocyanine material.Again with this photoproduction material with the dip coating coated on the conducting base that scribbles 1～2 μ m thickness polyamide precoat, after the oven dry, this photoproduction layer thickness is 0.2～0.8 μ m.At last, still contain the chlorohydrocarbon solution of hydrazone class transferring material (III) and polycarbonate resin (IV) with dip coating coated on the photoproduction layer, (III): weight ratio (IV) is 0.5～2.0, after the oven dry, this transport layer thickness is 15～35 μ m, and having made the light frequency responding range is 7.5 * 10 ¹⁴～3.3 * 10 ¹⁴The double-deck organic photoconductor of hertz.R ₂-N＝N-R ₁-N＝N-R ₂ (I)

Method of the present invention, be at normal temperatures, azo compound that purifying is good (I) and the phthalocyanine-like compound (II) that purifying is good carry out blend with the method for sand milling in the presence of appropriate solvent compound, making mean grain size is azo-phthalocyanine compound of 0.1～0.25 μ m, select for use then and can wrap up, thereby obtain stable organic compound charge carrier photoproduction material with the fluoropolymer resin that azo compound, phthalocyanine-like compound and sand milling solvent are complementary.Obviously, method of the present invention, avoided because of the polarity different caused aggegation sedimentations of azo compound with phthalocyanine-like compound, simultaneously, in the method for the present invention, owing to selected appropriate solvent, made azo-phthalocyanine compound help the crystal formation conversion that photoconductive property improves, thereby obtained to have the compound charge carrier photoproduction material that stable and superior wideband rings.

Elaborate below in conjunction with embodiment.

Embodiment 1, accurately take by weighing the 0.5 part of azo compound (IA) crossed of purifying and 0.5 part TiOPc (II) (parts by weight of crossing of purifying, put into the sand milling device that 150 parts of tetrahydrofurans and 250 parts of beaded glasses (diameter 1mm) are housed down together), sand milling made the compound charge carrier photoproduction of the azo-phthalocyanine particles of material that mean grain size is 0.10～0.25um in 1 hour at normal temperatures, this particle dispersion liquid that makes is transferred in the tetrahydrofuran solution that is dissolved with 15 parts of α-naphthalene phenylhydrazone (III) and 10 parts of bisphenol-a polycarbonates (IV) wraps up dispersion, obtain stable organic composite photoelectric and lead the dispersion of materials feed liquid.Again will this organic composite photoelectric leading the dispersion of materials feed liquid pours in the hopper of dip coating apparatus, with the direct coated of dip coating on the cleaning aluminum pipe that 30 * 355mm had polished or on the cleaning aluminium flake of 2 * 2cm, dried 2 hours for 80 ℃, making coated thickness is the single-organic photoconductive body of 30 μ m.

Embodiment 2, change azo-compound (IA) into azo-compound (IB), other all operations are with embodiment 1.

Embodiment 3, on the cleaning aluminum pipe that 30 * 240mm had polished, be the precoat of 1 μ m polyamide with dip coating elder generation coated thickness.

Charge carrier photoproduction layer material is to be mixed with 0.5 part of TiOPc (II) by 0.5 part of azo compound (IA), put into the sand milling device that 150 parts of cyclohexanone and 250 parts of beaded glasses (diameter 1mm) are housed, sand milling is 1 hour at normal temperatures, making mean grain size is the compound charge carrier photoproduction of the azo-phthalocyanine particles of material of 0.10～0.25 μ m, this particle dispersion liquid that makes is transferred in the cyclohexanone solution that is dissolved with 0.5 part of polyvinyl butyral resin wraps up dispersion, obtain the dispersion feed liquid of stable compound charge carrier photoproduction material.Again with dip coating with above-mentioned compound charge carrier photoproduction dispersion of materials feed liquid coated on aluminum pipe that scribbles precoat or aluminium flake, 100 ℃ the oven dry 1 hour, the photoproduction layer thickness is 0.5 μ m.

Carrier transmission material is the dichloroethane solution of 0.5 part of α-naphthalene phenylhydrazone and 0.5 part of polycarbonate resin, still with dip coating with this carrier transport layer material feed liquid coated on the charge carrier genetic horizon, dried 1 hour down for 80 ℃, the carrier transport layer thickness is 25 μ m, makes double-deck organic photoconductor.

Embodiment 4, change azo-compound (IA) into azo-compound (IB), other all operations are with embodiment 3.

The compound charge carrier photoproduction material that comparative example 1, the azo compound of crossing with 1 part of single purifying (IA) replace 0.5 part of azo-compound (IA) and TiOPc (II) to form, other are operated with embodiment 1.

Comparative example 2, the azo compound of crossing with 1 part of single purifying (IB) replace 0.5 part of azo-compound (IB) and TiOPc (II), and other are operated with embodiment 2.

The compound charge carrier photoproduction material that comparative example 3, the TiOPc of crossing with 1 part of single purifying (II) replace 0.5 part of azo compound (IA) and 0.5 part of TiOPc (II) to form, other are operated with embodiment 1.

The compound charge carrier photoproduction material that comparative example 4, the azo compound of crossing with 1 part of single purifying (IA) replace 0.5 part of azo-compound (IA) and 0.5 part of TiOPc (II) to form, other are operated with embodiment 3.

The compound charge carrier photoproduction material that comparative example 5, the azo compound of crossing with 1 part of single purifying (IB) replace 0.5 part of azo-compound (IB) and 0.5 part of TiOPc (II) to form, other are operated with embodiment 4.

Comparative example 6, the compound charge carrier photoproduction material that the TiOPc of crossing with 1 part of single purifying (II) replaces 0.5 part of azo-compound (IA) and 0.5 part of TiOPc (II) to form, other are operated with embodiment 3.The photoconductivity of table 1. embodiment and comparative example

Table 1. embodiment and photoconductivity relatively

	Light source	V 0(V)	V r(V)	R d(V/S)	P d(V/S)	T 1/2(S)
							Embodiment 1	The visible light near infrared light	-742 -719	0 -14	32 35	100 96	0.125 0.1875
Embodiment 2	The visible light near infrared light	822 -831	-7 -25	32 30	100 94	0.125 0.1875
							Embodiment 3	The visible light near infrared light	-710 705	-29 -39	31 37	92 89	0.1875 0.25
Embodiment 4	The visible light near infrared light	680 -719	-22 -35	37 42	94 88	0.1875 0.25
							Comparative example 1	The visible light near infrared light	-821 -805	0 -75	15 17	100 65	0.125 0.6875

Comparative example 2	The visible light near infrared light	-841 -850	-9 -78	13 15	100 61	0.125 0.6875
							Comparative example 3	The visible light near infrared light	-680	-12	27	96	0.1875
Comparative example 4	The visible light near infrared light	-861 -857	-12 -129	13 13	98 45	0.1875 0.9375
							Comparative example 5	The visible light near infrared light	-862 -905	-18 -131	18 19	98 42	0.1875 0.9375
Comparative example 6	The visible light near infrared light	-805 811	-83 -31	35 44	54 86	0.875 0.375

Photoconductor is coated with the apparatus for coating coated with dip coating.Earlier conducting base is contained on the connecting rod, keep vertical, start jacking gear, conducting base is immersed in the feed liquid, this moment feed liquid through overflow to basin, then, oppositely start jacking gear, with conducting base be promoted to lentamente break away from liquid level fully after, unload, oven dry is measured, and promptly finishes the coated process one time.

The photoconductive property test is to carry out on the surface electrostatic potentiometer, and light source is the 5W incandescent lamp, and illumination is adjustable, and by different color filter intercepting visible lights and near infrared light, photoconductor surface fills negative electricity, and the charger charging potential is 7KV, and this instrument is a system controlled by computer.Can write down the light decay family curve PIDC of each tested photoconductor automatically:

V0 is tested photoconductor surface charging potential;

Vr is the rest potential of exposure tested photoconductor surface after 5 seconds;

Rd (volt/second) is the dark-decay speed of tested photoconductor surface current potential;

Pd (%) is the percent of illumination tested photoconductor surface potential decay after 1 second;

T1/2 is that tested photoconductor surface potential decay arrives half required time (second) under the illumination;

I is the intensity (lux) of illumination at photoconductor surface, and I is 30 luxs during test.E1/2=T1/2I is illustrated under the illumination tested photoconductor surface potential decay to the required energy of a half (lux second).

Obviously, under same experimental conditions, Rd is more little, and Pd is big more, and T1/2 is more little, and E1/2 is more little, and the photoconductive property of tested photoconductor is good more; Otherwise Rd is big more, and Pd is more little, and T1/2 is big more, and E1/2 is big more, and then the photoconductive property of tested photoconductor is poor more.

Main points of the present invention are compound by the blend of azo-compound and phthalocyanine-like compound, and wrap up with suitable polymer resin solution, make to have the charge carrier photoproduction material that stable and superior wideband rings.Therefore, raw materials used necessary purifying, drying, preparation process must strict grasp the particle diameter of the compound proportioning of blend, the compound charge carrier photoproduction of azo-phthalocyanine material of azo compound and phthalocyanine-like compound and fluoropolymer resin and distribution thereof, with and evenly parcel be dispersed in the polymer resin solution, should not bring other impurity and the evenly improper operation of parcel dispersion in polymer resin solution that comprise moisture content therefrom into.

Use the individual layer and the double-deck organic photoconductor of the method for the invention preparation, after the photoconductive property test, the result shows, all is better than the individual layer and the double-deck organic photoconductor of corresponding single azo class charge carrier photoproduction material or corresponding single phthalocyanines charge carrier photoproduction material preparation.

Claims (2)

1. A method for preparing a broadband organic photoconductor, characterized in that: a. First, at normal temperature, the purified azo compound (I) and the purified phthalocyanine compound (II), the weight ratio of (I):(II) is 8:2～2:8 , in the presence of cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solvents, sand milling for 0.5 to 1.5 hours to prepare an azo-phthalocyanine composite carrier photogenerated material (I-II) with an average particle size of 0.10 to 0.25 μm ; b. Then, transfer (I-II) to cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solution containing hydrazone carrier transport material (III) and polycarbonate (IV) for wrapping to obtain a stable organic Composite photoconductive material dispersion system, (I-II): (III): (IV) weight ratio is 1: 10～20:5～20, at last, this organic composite photoconductive material dispersion system is directly It is coated on a conductive substrate, and the coating thickness after drying is 20-35 μm, and a single-layer organic photoconductor with an optical frequency response range of 7.5×10 ¹⁴ to 3.3×10 ¹⁴ Hz is made. R ₂ -N=NR ₁ -N=NR ₂ (I)

2. A method for preparing a broadband organic photoconductor, characterized in that: a. First, at normal temperature, the purified azo compound (I) and the purified phthalocyanine compound (II), the weight ratio of (I):(II) is 8:2～2:8 , in the presence of cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solvents, sand milling for 0.5 to 1.5 hours to prepare an azo-phthalocyanine composite carrier photogenerated material (I-II) with an average particle size of 0.10 to 0.25 μm ; c. Then, (I-II) is transferred to cyclohexanone or tetrahydrofuran or chlorinated hydrocarbon solution containing polyvinyl butyral resin (V) for wrapping, the weight ratio of (I-II): (V) 1: 0.5-2.0, to prepare a stable azo-phthalocyanine composite carrier photo-generated material, and then apply the photo-generated material to the conductive material that has been coated with a polyamide resin pre-coating with a thickness of 1-2 μm. On the substrate, after drying, the thickness of the photo-generated layer is 0.2-0.8 μm. Finally, the photo-generated layer is still coated with chlorinated hydrocarbon containing hydrazone transmission material (III) and polycarbonate resin (IV) by dip coating method. solution, the weight ratio of (III):(IV) is 1:0.5-2.0, after drying, the thickness of the transmission layer is 15-35 μm, and the optical frequency response range is 7.5×10 ¹⁴ ～3.3×10 ¹⁴ Hz. double-layer organic photoconductor. R ₂ -N=NR ₁ -N=NR ₂ (I)