Abstract: The present invention relates to a composite tubular article for use as the fixing belt in an image-forming device such as a copying machine etc., particularly as a fixing belt suited for thermal fixing, and also relates to a process for producing the same.Conventionally known as an image-fixing belt is a belt consisting of a polyimide resin as the inner layer and a fluoroplastic as the outer layer. However, this fixing belt has problems that clear images cannot be obtained because the thickness of each layer is uneven, and that unglossed, so-called matt images cannot be obtained because the belt surface is smooth.This invention provides a composite tubular article comprising a tubular inner layer made of a polyimide resin and a tubular outer layer made of a fluoroplastic, the outer circumferential surface of the fluoroplastic tubular outer layer having a surface roughness of 1 to 10 .mu.m.

Abstract: An optical disk comprising a pair of substrates, each having a recording surface and a reflective layer in super-position on one side, is disclosed. Such an optical disk has satisfactory shear adhesive strength and peeling strength under high temperature and high moisture conditions.