Aliphatic petroleum-based resins, method to control their softening point and molecular weight and hot melt pressure sentitive adhesive containing same

摘要

The invention provides a petroleum-based aliphatic resin havinga) a Ring and Ball (R&B) softening point in the range of 75 to 110°C,b) a weight average molecular weight (Mw) of 1000 to 2600 Dalton, a z-average molecular weight (Mz) from 1900 to 5000 Dalton and an Mw/Mn below 2.0,c) a level of aromatic protons below 1.5 % with respect to the total protons determined by ¹H-NMR, andd) a mixed methylcyclohexane aniline cloud point (MMAP) of 90°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.