▎ 摘　　要

NOVELTY - Surface patterned cross-linked polyurethane elastomer, comprises polyurethane with a dynamic cross-linked structure, and in a partial area of its surface; the polyurethane with dynamic crosslinking structure also has permanent chemical crosslinking structure, the polyurethane with a dynamic crosslinking structure is obtained by polymerization reaction of a raw material composition including benzophenone compounds, isocyanate compounds and polyols, the benzophenone compounds include compounds with phenolic hydroxyl or aniline groups, and the isocyanate compound includes a compound having three or more isocyanate groups. USE - The surface patterned cross-linked polyurethane elastomer is useful for manufacturing flexible circuit board (claimed). ADVANTAGE - The polyurethane elastomer: has excellent mechanical properties; can realize self-healing by heating; and can laminate patterned conductive layers. The flexible circuit board of the polyurethane elastomer: has excellent mechanical properties; can realize self-repair of mechanical and conductive properties by heating; and has excellent resistance to falling off, and high precision of the conductive layer. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: preparing surface patterned crosslinked polyurethane elastomer comprising (i) carrying out polymerization of benzophenone compounds, isocyanate compounds, polyol and optionally catalyst feedstock composition to obtain polyurethane with dynamic crosslinking structure, and (ii) irradiating ultraviolet light to the polyurethane with a dynamic crosslinking structure through a patterned mask; circuit substrate, comprising the surface-patterned cross-linked polyurethane elastomer; flexible circuit board, comprising the circuit substrate, and a conductive layer stacked on the circuit substrate, preferably the conductive layer includes at least one conductive fillers including metal nanowires, carbon nanotubes, graphene, liquid metal and metal particles; manufacturing flexible circuit board comprising laminating conductive layer on the surface of the obtained surface-patterned cross-linked polyurethane elastomer.