Multilayer type electrophotographic photoconductor and image forming apparatus

1. A multilayer type electrophotographic photoconductor comprising a charge generating layer containing at least a charge generating agent on a base member directly or via an intermediate layer, and a charge transporting layer containing at least a charge transporting agent and a binder resin formed successively,

wherein the base member is aluminum;

the film thickness of the charge generating layer is a value within a range from 0.2 or more to below 0.38 μm,

the charge generating agent comprises a titanyl phthalocyanine crystal having a peak in a Bragg angle of 2θ±0.2°=27.2° in a CuKα characteristic X-ray diffraction spectrum and having one peak within a range of 270 to 400° C. other than a peak accompanied by the vaporization of adsorbed water in a differential scanning calorie analysis;

the charge transporting agent comprises a hole transporting agent represented by one of the following general formulae (3), and (5) to (6); and

wherein the light absorption degree at a 680 nm wavelength light beam in a photoconductive layer of the multilayer type electrophotographic photoconductor is of a value of 0.8 or less, and the light absorption degree at a 450 nm wavelength light beam is of a value of 1.0 or more;

wherein in the general formula (3), R 1 to R 12 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 13 , wherein R 13 is an alkyl group having 1 to 10carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, Ar 1 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and n is an integer of 0 to 2;

wherein in the general formula (5), X 2 is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, an unsubstituted hydrocarbon group having an aryl group having 6 to 30 carbon atoms, or a condensed polycyclic hydrogen group having 10 to 30 carbon atoms, R 24 to R 34 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 35 , wherein R 35 is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, R 24 to R 28 , R 29 and R 30 , R 31 and R 34 , and R 32 and R 33 may form a saturated or unsaturated ring by linking two substituents with each other, or R 26 may be a substituent of the following formula (5′) in addition to the above mentioned substituents;

in the general formula (5′), Ar 4 and Ar 5 are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and d is an integer of 0 to 2;

in the general formula (6), R 37 to R 46 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 47 , wherein R 47 is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, R 37 to R 41 , R 42 and R 43 and R 45 and R 46 may form a saturated or unsaturated ring by linking two substituents with each other, Ar 6 and Ar 7 are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms and e is an integer of 0 to 2.

2. The multilayer type electrophotographic photoconductor according to claim 1 , wherein the light absorption degree at a 680 nm wavelength light beam in the charge generating layer is of a value of 0.8 or less.

3. The multilayer type electrophotographic photoconductor according to claim 1 , wherein the content of the charge generating agent in the charge generating layer is of a value within a range of 30 to 80% by weight with respect to the total amount in the charge generating layer.

4. The multilayer type electrophotographic photoconductor according to claim 1 , wherein the light absorption degree at a 450 nm wavelength light beam in the charge transporting layer is of a value of 1.0 or more.

5. The multilayer type electrophotographic photoconductor according to claim 1 , wherein the time necessary for attenuating the charge potential to 95% of the potential range (V 1 -V 2 ) is 10 msec or less, with the premise that the initial charge potential of the multilayer type electrophotographic photoconductor is V 1 (V) and the charge potential after passage of 300 msec after the exposure is V 2 (V).

6. The multilayer type electrophotographic photoconductor according to claim 1 , wherein the ionizing potential of the charge transporting agent is a value within a range of 5.3 to 6.0 eV.

7. An image forming apparatus comprising a multilayer type electrophotographic photoconductor having a charge generating layer containing at least a charge generating agent on a base member directly or via an intermediate layer, and a charge transporting layer containing at least a charge transporting agent and a binder resin formed successively,

wherein the base member is aluminum;

the film thickness of the charge generating layer is a value within a range from 0.2 or more to below 038 μm,

the charge generating agent comprises a titanyl phthalocyanine crystal having a peak in a Bragg angle of 2θ±0.2°=27.2° in a CuKα characteristic X-ray diffraction spectrum and having one peak within a range of 270 to 400° C. other than a peak accompanied by the vaporization of adsorbed water in a differential scanning calorie analysis;

the charge transporting agent comprises a hole transporting agent represented by one of the following general formulae (3), and (5) to (6); and

wherein a charging means, an exposure means, a developing means and a transfer means are provided around the multilayer type electrophotographic photoconductor, the light absorption degree at a 680 nm wavelength light beam in a photoconductive layer of the multilayer type electrophotographic photoconductor is of a value of 0.8 or less, and the light absorption degree at a 450 nm wavelength light beam is of a value of 1.0 or more;

wherein in the general formula (3), R 1 to R 12 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 13 , wherein R 13 is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, Ar 1 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and n is an integer of 0 to 2;

wherein in the general formula (5), X 2 is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, an unsubstituted hydrocarbon group having an aryl group having 6 to 30 carbon atoms, or a condensed polycyclic hydrogen group having 10 to 30 carbon atoms, R 24 to R 34 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 35 , wherein R 35 is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, R 24 to R 28 , R 29 and R 30 , R 31 and R 34 , and R 32 and R 33 may form a saturated or unsaturated ring by linking two substituents with each other, or R 26 may be a substituent of the following formula (5′) in addition to the above mentioned substituents;

in the general formula (5′), Ar 4 and Ar 5 are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and d is an integer of 0 to 2;

in the general formula (6), R 37 to R 46 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 30 carbon atoms, or —OR 47 , wherein R 47 is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group, or an aryl group having 6 to 30 carbon atoms, R 37 to R 41 , R 42 and R 43 , and R 45 and R 46 may form a saturated or unsaturated ring by linking two substituents with each other, Ar 6 and Ar 7 are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms and e is an integer of 0 to 2.

8. The image forming apparatus comprising the multilayer type electrophotographic photoconductor according to claim 7 , wherein the ionizing potential of the charge transporting agent is a value within a range of 5.3 to 6.0 eV.