The invention relates to a process for assembling and repositioning at least two parts by means of a repositionable hot melt adhesive, wherein said parts are held together in assembled position when said adhesive is at a temperature T.sub.A and can be repositioned in relation to one another when said adhesive is heated to a temperature T.sub.C, wherein said adhesive comprises at least a formulation, which: at the temperature T.sub.C has the form of a mixture of polymer chains comprising at least pendant diene units X and of coupling molecules comprising at least two dienophile end groups Y, wherein said X units and said Y groups are arranged to be able to react with one another and to bond together by means of the Diels-Alder reaction at a temperature T.sub.DA and to be able to regenerate by means of the retro-Diels-Alder reaction at a temperature T.sub.RDA, at a temperature T.sub.A has the form of a three-dimensional network, in which the polymer chains are linked to one another by the coupling molecules by means of the Diels-Alder reaction, where T.sub.A<T.sub.RDAT.sub.C, where T.sub.DA ranges between 0 C. and 100 C. and T.sub.RDA ranges between 50 C. and 200 C., and T.sub.DA is strictly lower than T.sub.RDA. The polymer chain is a block copolymer comprising at least a first polymer block having a glass transition temperature Tg or a melting temperature Tf ranging between 40 C. and 200 C., and at least a second polymer block comprising at least pendant diene units X and having a glass transition temperature Tg or a melting temperature Tf lower than T.sub.DA.

A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene):diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistency of performances, and improved characteristics in terms of grip and/or resistance to laceration.

A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene):diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistency of performances, and improved characteristics in terms of grip and/or resistance to laceration.

A (iso-styrene/trans-butadiene):diene-terminated copolymer is described which includes (i) a polymeric block of styrene-butadiene consisting of a random sequence of butadiene in trans conformation and styrene in isotactic configuration, and (ii) a terminal polymeric block consisting of a sequence of one or more dienic monomers.

Concentrates containing specific functionalised diblock copolymers serve as effective additives for improving the cold flow behaviour of fuels and oils, the copolymers being derived from a terminally-unsaturated intermediate polymer obtained via a metallocene process involving hydrogen.

The invention relates to a process for assembling and repositioning at least two parts by means of a repositionable hot melt adhesive, wherein said parts are held together in assembled position when said adhesive is at a temperature T.sub.A and can be repositioned in relation to one another when said adhesive is heated to a temperature T.sub.C, wherein said adhesive comprises at least a formulation, which: at the temperature T.sub.C has the form of a mixture of polymer chains comprising at least pendant diene units X and of coupling molecules comprising at least two dienophile end groups Y, wherein said X units and said Y groups are arranged to be able to react with one another and to bond together by means of the Diels-Alder reaction at a temperature T.sub.DA and to be able to regenerate by means of the retro-Diels-Alder reaction at a temperature T.sub.RDA, at a temperature T.sub.A has the form of a three-dimensional network, in which the polymer chains are linked to one another by the coupling molecules by means of the Diels-Alder reaction, where T.sub.A<T.sub.RDAT.sub.C, where T.sub.DA ranges between 0 C. and 100 C. and T.sub.RDA ranges between 50 C. and 200 C., and T.sub.DA is strictly lower than T.sub.RDA.

The polymer chain is a block copolymer comprising at least a first polymer block having a glass transition temperature Tg or a melting temperature Tf ranging between 40 C. and 200 C., and at least a second polymer block comprising at least pendant diene units X and having a glass transition temperature Tg or a melting temperature Tf lower than T.sub.DA.

Polymeric compositions obtainable by free-radical polymerization of at least two different alkyl (meth)acrylates in the presence of at least one ethylene-vinyl ester copolymer, the alkyl (meth)acrylates used being a mixture comprising alkyl (meth)acrylates having linear C.sub.12- to C.sub.60-alkyl radicals and different alkyl (meth)acrylates having linear C.sub.1- to C.sub.11-alkyl radicals and/or branched C.sub.4- to C.sub.60-alkyl radicals and/or cyclic C.sub.6- to C.sub.20-alkyl radicals. The use of such polymeric compositions as pour point depressants for crude oils, mineral oils or mineral oil products.

Polymeric compositions obtainable by free-radical polymerization of at least two different alkyl (meth)acrylates in the presence of at least one ethylene-vinyl ester copolymer, the alkyl (meth)acrylates used being a mixture comprising alkyl (meth)acrylates having linear C.sub.12- to C.sub.60-alkyl radicals and different alkyl (meth)acrylates having linear C.sub.1- to C.sub.11-alkyl radicals and/or branched C.sub.4- to C.sub.60-alkyl radicals and/or cyclic C.sub.6- to C.sub.20-alkyl radicals. The use of such polymeric compositions as pour point depressants for crude oils, mineral oils or mineral oil products.

Metallic complexes having indenyl ligands can be used as an ingredient of a catalyst system. The catalyst system can be used in polymerizations of ethylenically unsaturated hydrocarbon monomers that include both olefins and polyenes. Embodiments of the catalyst system can provide interpolymers that include polyene mer and from 40 to 75 mole percent ethylene mer, with a plurality of the ethylene mer being randomly distributed. The catalyst system also can be used in solution polymerizations conducted in C.sub.5-C.sub.12 alkanes, yielding interpolymers that include at least 10 mole percent ethylene mer.

Metallic complexes having indenyl ligands can be used as an ingredient of a catalyst system. The catalyst system can be used in polymerizations of ethylenically unsaturated hydrocarbon monomers that include both olefins and polyenes. Embodiments of the catalyst system can provide interpolymers that include polyene mer and from 40 to 75 mole percent ethylene mer, with a plurality of the ethylene mer being randomly distributed. The catalyst system also can be used in solution polymerizations conducted in C.sub.5-C.sub.12 alkanes, yielding interpolymers that include at least 10 mole percent ethylene mer.