Multilayer electrophotographic photoconductor and image-forming apparatus
A photosensitive layer in a multilayer electrophotographic photoconductor includes a charge-generation layer including a charge-generating material having, as a major component, a titanyl phthalocyanine crystal which satisfies the conditions (A) and (B) below and a base resin, and a charge-transport layer including a charge-transporting material, the charge-generating material having, as a major component, the titanyl phthalocyanine crystal which has absorption at a wavelength of a charge-neutralizing light and which satisfies the conditions (A) and (B) or an X-form metal-free phthalocyanine crystal which has absorption at the wavelength of the charge-neutralizing light, and a binder resin. (A) In a Cu—Kα characteristic X-ray diffraction spectrum, one peak is present at a Bragg angle 2θ±0.2°=27.2°. (B) In a differential scanning calorimetry, one peak is present in a range of 270° C. to 400° C. except for peaks attributed to vaporization of adsorption water.
1. A multilayer electrophotographic photoconductor comprising:
an electrically conductive base; and
a photosensitive layer disposed on the electrically conductive base,
wherein the photosensitive layer includes:
a charge-generation layer including a charge-generating material consisting essentially of a titanyl phthalocyanine crystal which satisfies the conditions (A) and (B) below and a base resin, and
a charge-transport layer including (i) a charge-transporting material, (ii) the charge-generating material consisting essentially of the titanyl phthalocyanine crystal which satisfies the conditions (A) and (B) below or an X-form metal-free phthalocyanine crystal and (iii) a binder resin, the charge-generation layer and the charge-transport layer being stacked in that order,
wherein (A) in a Cu-Kα characteristic X-ray diffraction spectrum, one peak is present at a Bragg angle 2θ±0.2°=27.2°;
wherein (B) in a differential scanning calorimetry, one peak is present in a range of 270° C. to 400° C. except for peaks attributed to vaporization of adsorption water;
wherein, in the charge-transport layer, a ratio of the charge generating material to the charge transporting material is 0.005:50 to 0.01:50 by mass.
2. The multilayer electrophotographic photoconductor according to claim 1 , wherein the amount of the charge-generating material included in the charge-transport layer is about 0.005 to about 0.01 part by mass relative to 100 parts by mass of the binder resin or the base resin.
3. An image-forming apparatus comprising:
an image bearing member;
a charging operable portion for charging the surface of the image bearing member;
an exposing portion operable for exposing the surface of the image bearing member to form an electrostatic latent image;
a developing portion operable for developing the electrostatic latent image to form a toner image;
a transferring portion operable for transferring the toner image from the image bearing member to a transfer-receiving medium; and
a charge-neutralizing portion operable for neutralizing a charge from the surface of the image bearing member,
wherein the image bearing member is the multilayer electrophotographic photoconductor according to claim 2 .
4. An image-forming apparatus comprising:
an image bearing member;
a charging portion operable for charging the surface of the image bearing member;
an exposing portion operable for exposing the surface of the image bearing member to form an electrostatic latent image;
a developing portion operable for developing the electrostatic latent image to form a toner image;
a transferring portion operable for transferring the toner image from the image bearing member to a transfer-receiving medium; and
a charge-neutralizing portion operable for neutralizing a charge from the surface of the image bearing member,
wherein the image bearing member is the multilayer electrophotographic photoconductor according to claim 1 .
5. The image-forming apparatus according to claim 4 , wherein the charge-neutralizing light of the charge-neutralizing portion has a wavelength that is absorbed by the charge-generating material included in the charge-transport layer.
6. The multilayer electrophotographic photoconductor according to claim 1 , wherein the charge-transporting material is HTM-1 represented by the chemical formula below: