Underwater Pelletizing Method For Low Viscosity Hydrocarbon Resins

A method, comprising:

• heating a feed material comprising a hydrocarbon resin and at least one resin modifier in a compounding extruder to a temperature above the resin softening point up to 215° C. to form a modified resin melt, wherein the feed material has a Tg (DSC method) of from about 30° C. to about 110° C. and a viscosity less than 2.5 Pa-s (2500 cP), measured at a temperature 60° C. above a softening point of the resin;
• cooling the modified resin melt to a temperature of from 10° C. to 50° C. above the softening point;
• extruding the cooled modified resin melt through a multiple-orifice die into a water bath flowing across a surface of the die, wherein the water bath is supplied at a temperature below the Tg of the resin, to form a plurality of resin extrudates;
• cutting the resin extrudates to form a slurry of resin pellets;
• separating the slurry to recover dewatered resin pellets from a spent water stream;
• drying the dewatered pellets under low shear conditions;
• and
• cooling and recirculating the spent water stream to the water bath.

A method, comprising:

• mixing a hydrocarbon resin and a graft monomer in a reaction zone of a melt-mixing mechanism to graft the graft monomer onto the hydrocarbon resin and form a grafted hydrocarbon resin melt, wherein the hydrocarbon resin has a Tg (DSC method) of from about 30° C. to about 110° C. and a viscosity less than 2500 mPa-s (2500 cP), measured at the temperature of the reaction zone;
• cooling the grafted hydrocarbon resin melt in a cooling zone of the melt-mixing mechanism to a temperature below the temperature of the reaction zone and above the softening point up to 50° C. above the softening point;
• extruding the cooled grafted hydrocarbon resin melt through a multiple-orifice die into a water bath flowing across a surface of the die, wherein the water bath is supplied at a temperature below the Tg of the resin, to form a plurality of grafted hydrocarbon resin extrudates;
• cutting the grafted hydrocarbon resin extrudates at the surface of the die to form a slurry of grafted hydrocarbon resin pellets;
• separating the slurry to recover dewatered grafted hydrocarbon resin pellets from a spent water stream;
• and
• cooling and recirculating the spent water stream to the water bath, and
• wherein the hydrocarbon resin comprises an interpolymer of monomers selected from the group consisting of piperylenes, cyclic pentadienes, aromatics, limonenes, pinenes, amylenes, and combinations thereof and wherein the graft monomer comprises a bifunctional organosilane crosslinking agent of the formula:
• X3Si—R—F—[R—Si—X3]p
• wherein each X is independently a silicon functional group, each R is independently a divalent substituted or unsubstituted hydrocarbon group of from 1 to 20 carbon atoms, F is a monovalent or multivalent organo-functional group, p is 0 when F is monovalent and p is at least 1 when F is multivalent.