| abstract |
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. |