Titanyl phthalocyanin crystal, method for preparing the same and electrophotographic photoconductor

Abstract

According to the present invention, a titanyl phthalocyanin crystal excellent in storage stability in organic solvents, a method for preparing the same and an electrophotographic photoconductor using the same are provided. In the titanyl phthalocyanin crystal, the method for preparing such a titanyl phthalocyanin crystal and the electrophotographic photoconductor using the same, the titanyl phthalocyanin crystal is characterized by having the maximum peak at a Bragg angle 2θ±0.2°=27.2° in a CuKα characteristic X-ray diffraction spectrum and one peak within the range of 270 to 400° C. other than a peak accompanied by the vaporization of adsorbed water in a differential scanning calorimetric analysis.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a titanyl phthalocyanin crystal prepared from a titanyl phthalocyanin compound, the method for preparing the same and an electrophotographic photoconductor using the same. Particularly, the present invention relates to a titanyl phthalocyanin crystal excellent in the storage stability in organic solvents, the method for preparing the same and an electrophotographic photoconductor using the same. [0003] 2. Related Art [0004] Generally, organic photoconductors have been frequently and recently used in electrophotographic photoconductors applied in electrophotographic devices such as a copy machine and a laser printer, etc. upon such requirements as low cost and low environment polluting property, etc. Phthalocyanin pigments that are sensitive to a light of infrared to near-infrared wavelengths irradiated from a semiconductor laser or an infrared LED, etc. have been widely used as charg...

AI Technical Summary

Benefits of technology

The present invention provides a titanyl phthalocyanin crystal that has good storage stability in organic solvents and can form a good image with good electric characteristics when used in a photosensitive layer of an image forming device. The crystal has a peak at a prescribed Bragg angle in the CuKα characteristic X-ray diffraction spectrum and a peak within a predetermined temperature range in the differential scanning calorimetric analysis. The invention also provides a method for preparing this titanyl phthalocyanin crystal and an electrophotographic photoconductor using the same.

Problems solved by technology

However, according to Patent document 1, there has been found the problem that the prepared titanyl phthalocyanin crystal having a Y-type structure had a tendency to cause crystal transition to a β-type or α-type crystal in a coating solution for a photosensitive layer.

Therefore, there has been found the problem that the coating solution for the photosensitive layer is insufficient in storage stability, and thereby a photosensitive layer having good electric characteristics cannot be formed.

On the other hand, when a titanyl phthalocyanin crystal described in Patent document 2 or Patent document 3 was used, the crystal transition from the Y-type crystal in the coating solution for the photosensitive layer to a β-type crystal poor in sensitivity characteristic could be inhibited, but there found such a case that an image forming device using a photoconductor with a titanyl Phthalo-cyanin crystal described in Patent document 2 or Patent document 3 caused fogging and did not give a good image under a high temperature condition and a high humidity condition.

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