Bonding process

A process for manufacturing a long term implantable medical device comprising:

• providing a substrate for the device of, or having a section coated with, a silicone or silicone based material;
• flame treating a surface of the silicone or silicone based material;
• and
• bonding a polyurethane or polyurethane urea to the flame treated surface of the silicone or silicone based material,
• the polyurethane or polyurethane urea being selected from biostable polyurethanes and polyurethane ureas comprising soft segments and hard segments, the soft segments having a number average molecular weight of about 500-6000 and being formed from a polysiloxane diol or diamine of the formula (III)
• in which
• A and A′ are OH or NHR wherein R is H or C1-6 alkyl;
• R11, R12, R13 and R14 are independently selected from hydrogen or C1-6 alkyl;
• R15 and R16 are the same or different and are selected from propylene, butylene, pentylene, hexylene, ethoxypropyl, propoxypropyl and butoxypropyl;
• p is an integer of 1 or greater;
• and
• a polyether diol or diamine represented by the formula (I)
• A-[(CH2)m—X]nA′ (I)
• in which
• A is OH or NHR, X is O or NR and A′ is H wherein R is H or C1-4 alkyl;
• m is an integer of 4 to 18;
• and
• n is an integer of 2 to 50;
• and, optionally,
• a poly(alkylene) carbonate (II);
• a copoly[ether carbonate] macrodiol, formed by copolymerizing (I) and (II) and/or a silicon-containing poly(alkylene) carbonate (IV) formed by copolymerizing compound (III) and compound (II);
• and
• the hard segment being formed from a(C1-C12) alkane diol or a (C1-C12) alkane diamine and a diisocyanate.