▎ 摘　　要

NOVELTY - A semi-finished product comprises a cover layer (c1), a cover layer (c2) and a layer of foamable material between the cover layers (c1) and (c2). The foamable material comprises 50 wt.% or less carbon. The foamable material is formed by influence of heat, and cured after or during foaming. The foamable material adheres so firmly to at least one of the cover layers after foaming and curing, when the semi-finished product is separated by tension perpendicular to the layer boundaries, and a cohesive fracture occurs in the foamed material. USE - Semi-finished product used for forming foam sandwich structure (claimed). ADVANTAGE - The semi-finished product provides foam sandwich structure with improved mechanical property such as tack (surface stickiness), damping property (vibration damping), thermal conductivity (high or low), electroconductivity (high or low) and flame retardance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) production of semi-finished product, which involves (a) providing material for the cover layer (c1) and the cover layer (c2), (b) providing material for the layer of foamable material, and (c) joining the material from steps (a) and (b) to form a semi-finished product; and (2) production of foam sandwich structure, which involves (s1) providing the semi-finished product and (s2) foaming and curing the layer foamable material.