Electrically conductive, potentially adhesive composition

An electrically conductive, potentially adhesive composition which comprises

• (a) a thermoplastic block copolymer having elastic properties and consisting of polysiloxane and urethane groups with a concatenation of recurring repeat units of formula I and formula II
• --O--(X--O--CO--NH--Y--NH--CO--O).sub.m X--O-- (I)
• --CO--NH--(Y--NH--CO--O).sub.a --Z--(O--CO--NH--Y).sub.a --NH--CO--(II)
• in which
• Z, having the formula III, denotes a divalent radical bearing a polysiloxane block
• --L--Si(R.sub.2)--O--Si(R).sub.2 ].sub.n --L'-- (III)
• wherein
• L and L', which are identical or different, denote divalent radicals of formula IV
• --T--CHR.sub.1 --CR.sub.2 R.sub.3 -- (IV)
• where
• T denotes a divalent radical forming part of the molecular structure of an unsaturated isocyanate or an unsaturated alcohol of the formulae
• OCN--T--CR.sub.1 .dbd.CR.sub.2 R.sub.3
• or
• HO--T--CR.sub.1 .dbd.CR.sub.2 R.sub.3
• these radicals T being hydrocarbon in nature and containing 1 to 20 carbon atoms, or said radicals including one or more hetero atoms or groups chosen from oxygen, sulfur, silicon and nitrogen atoms and ester or amide groups,
• R.sub.1, R.sub.2 and R.sub.3 independently denote a hydrogen atom or an alkyl or aryl group, or R.sub.1 and R.sub.2 together are alkylene,
• R, which are identical or different, denote alkyl radicals containing 1 to 5 carbon atoms or said alkyl radicals containing 1 to 7 chlorine or fluorine atoms or mixture thereof;
• cycloalkyl containing 3 to 8 carbon atoms or said cycloalkyl radicals containing 1 to 4 chlorine or fluorine atoms or mixture thereof;
• alkenyl radicals containing 2 to 5 carbon atoms;
• aryl or alkylaryl radicals containing 6 to 8 carbon atoms, or said aryl radicals containing 1 to 4 chlorine or fluorine atoms or mixture thereof;
• n is a number from to 1000,
• X and Y denote divalent radicals of hydrocarbon nature corresponding, respectively, to the diol X(OH).sub.2 and to the diisocyanate Y(NCO).sub.2, each containing 2 to 20 carbon atoms,
• m denotes a number from 1 to 20, and
• z is zero or 1, and
• (b) an effective amount, sufficient to afford electrical conductivity to the composition, of particles with at least the surface of said particles being electrically conductive.