HOT MELT ADHESIVE COMPOSITION

1 - 24 . (canceled)

25 . A hot melt adhesive composition comprising:

i) a first metallocene-catalyzed propylene-based copolymer;

ii) a second metallocene-catalyzed propylene-based copolymer;

iii) a polyolefin copolymer selected from the group consisting of:

iii-1) acid-grafted polyolefin copolymer;

iii-2) a copolymer based on olefins and unsaturated monomers containing acid groups or anhydride groups; and

iii-3) mixtures thereof; and

iv) a tackifier;

v) optionally a third metallocene-catalyzed propylene-based copolymer;

wherein each of the metallocene-catalyzed propylene-based copolymers i) and ii) comprises, independently of each other, from 1% to 20% by weight of ethylene units.

26 . The hot melt adhesive composition according to claim 25 , wherein the first metallocene-catalyzed propylene-based copolymer i) comprises more than 60% by weight, of propylene units relative to the weight of said copolymer.

27 . The hot melt adhesive composition according to claim 25 , wherein the first metallocene-catalyzed propylene-based copolymer i) has a glass transition temperature from-75° C. to −10° C.

28 . The hot melt adhesive composition according to claim 25 , wherein the viscosity at 190° C. of the first metallocene-catalyzed propylene-based copolymer i) ranges from 700 mPas to 10,000 mPas.

29 . The hot melt adhesive composition according to claim 25 , wherein the first metallocene-catalyzed propylene-based copolymer i) has an enthalpy of melting above 20 J/g.

30 . The hot melt adhesive composition according to claim 25 , wherein the second metallocene-catalyzed propylene-based copolymer ii) comprises more than 60% by weight of propylene units relative to the weight of said copolymer ii).

31 . The hot melt adhesive composition according to claim 25 , wherein the second metallocene-catalyzed propylene-based copolymer ii) has a glass transition temperature from-75° C. to −10° C.

32 . The hot melt adhesive composition according to claim 25 , wherein the second metallocene-catalyzed propylene-based copolymer ii) has an enthalpy of melting from 5 J/g to 10 J/g.

33 . The hot melt adhesive composition according to claim 25 , wherein the acid-grafted polyolefin copolymer iii-1) has a density of from 0.86 to 0.89 g/cm 3 .

34 . The hot melt adhesive composition according to claim 25 , wherein the acid-grafted polyolefin copolymer iii-1) has a weight average molecular weight (Mw) ranging from 20 000 g/mol to 80 000 g/mol.

35 . The hot melt adhesive composition according to claim 25 , wherein the acid-grafted polyolefin copolymer iii-1) has a viscosity higher or equal to 2000 mPas at 190° C.

36 . The hot melt adhesive composition according to claim 25 , wherein the acid-grafted polyolefin copolymer iii-1) is an acid-grafted copolymer of ethylene and propylene, or an acid-grafted terpolymer of ethylene, propylene and 1-butene.

37 . The hot melt adhesive composition according to claim 25 , wherein the acid-grafted polyolefin copolymer iii-1) is a maleic anhydride-grafted polyolefin copolymer.

38 . The hot melt adhesive composition according to claim 25 , wherein the copolymer iii-2) comprises more than 50% by weight of olefin units, based on the total weight of said copolymer iii-2);

and/or

the copolymer iii-2) comprises less than 10% by weight, of unsaturated monomer containing acid groups or anhydride groups based on the total weight of said copolymer iii-2).

39 . The hot melt adhesive composition according to claim 25 , wherein the third metallocene-catalyzed propylene-based copolymer v) has a melt flow rate ranging from 3 g/min to 100 g/min.

40 . The hot melt adhesive composition according to claim 25 , comprising a tackifier selected from the group consisting of:

(a) Aliphatic and cycloaliphatic petroleum hydrocarbon resins having Ring and Ball softening points from 90° C. to 160° C. as determined by ASTM method E28-58T, the latter resins resulting from the polymerization of monomers consisting primarily of aliphatic and/or cycloaliphatic olefins and diolefins; also included are the hydrogenated aliphatic and cycloaliphatic petroleum hydrocarbon resins;

(b) Aromatic petroleum hydrocarbon resins and the hydrogenated derivatives thereof;

(c) Aliphatic/aromatic petroleum derived hydrocarbon resins and the hydrogenated derivatives thereof;

(d) Aromatic modified cycloaliphatic resins and the hydrogenated derivatives thereof;

(e) Polyterpene resins having a softening point from 95° C. to 140° C., the latter polyterpene resins generally resulting from the polymerization of terpene hydrocarbons, in the presence of Friedel-Crafts catalysts at moderately low temperatures; the hydrogenated polyterpene resins are also included;

(f) Copolymers and terpolymers of natural terpenes;

(g) Natural and modified rosin;

(h) Glycerol and pentaerythritol esters of natural and modified rosin;

(i) Phenolic-modified terpene resins;

(j) Mixtures thereof.

41 . The hot melt adhesive composition according to claim 25 , characterized in that it does not comprise acid-modified tackifier.

42 . The hot melt adhesive composition according to claim 25 , characterized in that it comprises a plasticizer.

43 . The hot melt adhesive composition according to claim 25 , characterized in that it does not comprise an acid-modified wax.

44 . The hot melt adhesive composition according to claim 25 , wherein the viscosity at 160° C. ranges from 500 to 10,000 mPas.

45 . The hot melt adhesive composition according to claim 25 , comprising:

from 5% to 30% by weight of copolymer i);

from 2% to 40% by weight of copolymer ii);

from 2% to 35% by weight of polyolefin iii); and

from 25% to 65% by weight of a tackifier.

46 . The hot melt adhesive composition according to claim 25 , characterized in that it does not comprise propylene homopolymer.

47 . An adhesive for bonding two substrates together, or as a coating on the surface of a substrate, the adhesive comprising the hot melt adhesive composition according to claim 25 .

48 . Process of manufacturing an assembly product or laminate comprising:

a step (i) of heating the hot-melt adhesive composition according to claim 25 , for at least a period of time long enough to render the hot melt adhesive composition liquid enough to be applied on a substrate, then

a step (ii) of coating said composition on a first substrate, then

a step (iii) of putting into contact the coated surface of the first substrate with the surface of a second substrate, so as to form an adhesive joint bonding the two substrates.