Adhesive composition, process for producing the same, molded objects, and process for producing heat-shrinkable tube

A process for producing a multi-layer heat-shrinkable tube comprising a hot-melt adhesive inner layer, which process comprises the following steps:

• co-extruding a radiation-crosslinking composition and a fluorine-containing polymer composition into a 2-layer tube-shaped product having an outer layer composed of the radiation-crosslinking composition and an inner layer composed of the fluorine-containing polymer composition, wherein the radiation-crosslinking composition comprises a fluorine-containing polymer and a polyfunctional monomer, and wherein the fluorine-containing polymer composition comprises 100 parts by weight of a fluorine-containing polymer and 2 to 30 parts by weight of an unsaturated compound containing at least one polar group selected from the group consisting of an epoxy group and a carboxyl group;
• irradiating the tube-shaped product with ionizing radiation to concurrently crosslink the radiation-crosslinking composition of the outer layer and graft-modify the fluorine-containing polymer composition of the inner layer, wherein the fluorine-containing polymer of the fluorine-containing polymer composition is graft-modified with the unsaturated compound;
• expanding the irradiated tube-shaped product in a radial direction thereof under heating;
• and
• cooling the expanded tube-shaped product to fix the expanded tube-shaped product,
• wherein a degree of graft-modification is controlled by adjusting a proportion of the unsaturated compound and a quantity of said ionizing radiation.