RECYCLING A MULTILAYER SYSTEM

1 .- 17 . (canceled)

18 . A multilayer system F1 comprising:

a layer C1 comprising at least one polypropylene,

an adhesive layer Ad consisting of a hot-melt pressure-sensitive adhesive composition CA comprising:

i. from 40% to 80% by weight of at least one copolymer A comprising more than 80% by weight of units derived from but-1-ene;

ii. optionally at least one copolymer T comprising more than 50% by weight of units derived from propylene; and

iii. at least one nonhydrogenated tackifying resin obtained by polymerization, or copolymerization with an aromatic hydrocarbon, of mixtures of unsaturated aliphatic hydrocarbons having from 4 to 6 carbon atoms obtained from petroleum cuts; and

a layer C2 comprising at least one polypropylene,

said multilayer system F1 comprising at least 80% by weight of polypropylene or of a mixture of polypropylenes, relative to the total weight of said system.

19 . The multilayer system F1 as claimed in claim 18 , characterized in that the hot-melt pressure-sensitive adhesive composition CA comprises from 45% to 80% by weight of copolymer(s) A, relative to the total weight of said composition.

20 . The multilayer system F1 as claimed in claim 18 , characterized in that the copolymer A comprises more than 82% by weight of units derived from but-1-ene.

21 . The multilayer system F1 as claimed in claim 18 , characterized in that the copolymer A is a but-1-ene-ethylene copolymer.

22 . The multilayer system F1 as claimed in claim 18 , characterized in that the hot-melt pressure-sensitive adhesive composition CA comprises from 1.5% to 4.5% by weight of copolymer(s) T, relative to the total weight of said composition CA.

23 . The multilayer system F1 as claimed in claim 18 , characterized in that the copolymer T is a propylene-ethylene-butene copolymer T.

24 . The multilayer system F1 as claimed in claim 18 , characterized in that the copolymer T comprises from 1% to 25% by weight of units derived from ethylene.

25 . The multilayer system F1 as claimed in claim 18 , characterized in that the total content of tackifying resin(s) iii) ranges from 18.5% to 58.5% by weight, relative to the total weight of said composition CA.

26 . The multilayer system F1 as claimed in claim 18 , characterized in that the hot-melt pressure-sensitive adhesive composition consists of:

i) from 40% to 80% by weight of at least one copolymer A;

ii) from 1.5% to 4.5% by weight of at least one copolymer T;

iii) at least one nonhydrogenated tackifying resin obtained by polymerization, or copolymerization with an aromatic hydrocarbon, of mixtures of unsaturated aliphatic hydrocarbons having from 4 to 6 carbon atoms obtained from petroleum cuts; and

iv) from 0% to 5% by weight of additional component chosen from the group consisting of stabilizers (antioxidants), plasticizers, anticaking agents, pigments, dyes, organic fillers, mineral fillers and mixtures thereof.

27 . The multilayer system F1 as claimed in claim 18 , characterized in that it comprises at least 80%, of polypropylene or of a mixture of polypropylenes, relative to the total weight of said system.

28 . A recycle article comprising the multilayer system F1 as defined in claim 18 .

29 . The recycled article of claim 28 , wherein the recycled article is a single-layer film, a laminate, a (multilayer) complex or a molded article.

30 . The recycled article of claim 28 comprising at least 90%, of polypropylene or of a mixture of polypropylenes, relative to the total weight of said recycled article.

31 . The recycled article of claim 28 having improved impact strength.

32 . The recycled article of claim 28 , wherein the impact strength of the recycled article comprising said hot-melt pressure-sensitive adhesive composition CA is at least 2%, improved, relative to a control article consisting of 100% polypropylene and devoid of said hot-melt pressure-sensitive adhesive composition.

33 . A process for preparing a recycled article, said process comprising:

a) providing the multilayer system F1 as claimed in claim 18 ;

b) converting the multilayer system F1 into flakes;

c) optionally mixing the flakes obtained in step b) with recycled or virgin polypropylene;

d) converting the flakes from step b) or the mixture from step c) into a recycled article.