Process For The Manufacture Of Flexible Pipe

A process for the manufacture of flexible pipe from a composition comprising: a polymeric part (a) consisting of a thermoplastic polymer obtained by homopolymerisation or copolymerisation of a monomer of butene-1, or a blend of a thermoplastic polymer obtained by homopolymerisation or copolymerisation of a monomer of butene-1 with one or more compatible thermoplastic polymers, a polydiorganosiloxane (b) having a minimum Williams plasticity of 30 determined by the ASTM 926 test method and an average of at least 2 alkenyl radicals per molecule, an organohydrido silicon compound (c) having an average per molecule of at least 2 silicon atoms bound directly to a hydrogen atom, a hydrosililation catalyst (d) which process comprises (i) the provision of a cured polydiorganosiloxane (B1) obtained by crosslinking of the compounds (b) and (c) in the presence of catalyst (d), (ii) causing the cured polydiorganosiloxane (B1) to be dispersed in the polymeric part (a) thus obtaining a thermoplastic elastomer and (iii) moulding, for example by extrusion, the thermoplastic elastomer into a flexible pipe. The thermoplastic elastomer used and the resulting pipes comply with the requirements of standard KTW-270 (A) in relation to drinking water contamination.