Abstract: The invention relates to aromatic modified aliphatic hydrocarbon resins giving excellent balance between tack and shear properties even at low coating weights. These resins are characterized in that they have a Ring and Ball (R&B) softening point of 94° C. or lower, a weight average molecular weight (Mw) of not more than 2000 Dalton, a Z-average molecular weight (Mz) of not more than 6000 Dalton and a mixed methylcyclohexane aniline cloud point (MMAP) between 25 and 45° C. The aromatic modified aliphatic hydrocarbon resins of the invention may be prepared by subjecting polymerization feeds containing petroleum feeds which comprise (a) C5 and C6 olefins and/or diolefins including cycloolefins, (b) aromatic monomers and (c) (di-)cyclodiolefins to a Friedel-Crafts polymerization. The invention is also directed to the use of the aromatic modified aliphatic hydrocarbon resins as mono-tackifiers in adhesive formulations as well as to an adhesive tape comprising these resins.

Abstract: The invention provides a petroleum-based aliphatic resin having: a) a Ring and Ball (R&B) softening point in the range of about 75 to about 110.degree. C., b) a weight average molecular weight (Mw) of about 1000 to about 2600 Dalton, a z-average molecular weight (Mz) from about 1900 to about 5000 Dalton and an Mw/Mn below about 2.0, c) a level of aromatic protons below about 1.5% with respect to the total protons determined by .sup.1 H-NMR, and d) a mixed methylcyclohexane aniline cloud point (MMAP) of about 90.degree. C. or less. The resins according to the invention are characterized by a high amount of cyclic structures. Further disclosed is a method of independently controlling the R&B softening point and the molecular weight of an aliphatic resin composition during its preparation by polymerization of a petroleum-based feed, the method being characterized in that the amount of cyclic structures in the resins is increased.