Patent ID: 6699550
Filing Date: 2004-03-02
Classification: C08K,Y10T

Abstract:
A cylindrical resinous base-body for photosensitive drums to be used for an electrophotographic process, being made of an electroconductive resin composition and simultaneously satisfying the following requirements:(1) a specific gravity of said resin composition is from 1.1 to 1.7, (2) an apparent viscosity of said resin composition at the apparent shear rate of 104Sâˆ’1 is from 1Ã—102 poise to 3Ã—103 poise, (3) an Izot impact value of the said resin composition is 30 J/m or greater, (4) a water absorption percentage of the said resin composition is 1.5% or less, (5) a load flexure temperature of the said resin composition is 150Â° C. or higher, (6) a change in dimension of the external diameter of said base-body is 1.5% or less, and (7) a surface resistance of said base-body is 1Ã—103 &OHgr;/&square; (ohm/square) or less; (8) a flexural modulus of said resin composition is 4.0Ã—106 kg-mm2 or greater; (9) a variation of an external diameter of each end of said base-body is 0.1 mm or less when defined as a diameter difference before and after said base-body is left under a condition of 50Â° C. and 90% RH for 24 hrs; (10) a variation of a straightness of said base-body is 40 &mgr;m or less when defined as a straightness difference before and after said base-body is left at 120Â° C. for 2 hrs; (11) a dimensional variation of an entire length of said base-body is 0.15% or less; and (12) a surface roughness of said base-body is 0.8 &mgr;m or less in terms of a center-line average roughness Ra, 1.6 &mgr;m or less in terms of a maximum height Rmax, and in terms of a 10-point average roughness, Rz; said electroconductive resin composition comprising at least one resin selected from the group consisting of polyamide resin and low water absorption resin, an electroconductive agent in an amount of 10-40% by mass based on a total amount of the electroconductive resin compositions, and at least one inorganic filler in an amount of 1 to 30% by mass based on the total amount of the electroconductive resin compositions; said polyamide resin being selected from the group consisting of nylon-11, nylon-12, nylon-46, nylon-6, nylon-66, nylon-MXD6, nylon-610, nylon-612, nylon-1212 and copolymers thereof; and said low water absorption resin being selected from the group consisting of polypropylene, polyphenylene ether and polyphenylene sulfide.