Process for preparing flowable amorphous poly-alpha olefin adhesive pellets

摘要

The present invention relates to a process for producing free-flowing, agglomeration resistant amorphous poly-alpha-olefin based adhesive pellets. The process includes (a) extruding the adhesive through an orifice of a die plate immersed in a cooling fluid; (b) cutting the adhesive into a plurality of pellets in the cooling fluid; (c) solidifying the pellets at a temperature range of about 25° C. to about 40° C. for at least 30 minutes; and (d) separating the pellets from the recrystallization fluid and drying the pellets. The pellets harden at least three folds faster than conventionally formed pellets.

主权项

1. A process for forming a plurality of hot melt adhesive pellets comprising the steps of:
a) extruding an adhesive through an orifice of a die plate immersed in a cooling fluid, which has a temperature T1; b) cutting the adhesive into a plurality of pellets in the cooling fluid; c) solidifying the pellets in a recrystallization fluid at temperature T2 for at least 30 minutes and up to 24 hours; d) separating the pellets from the recrystallization fluid and drying the pellets; wherein the T1 is less than about 45° F. and the T2 is higher than T1 by at least 30° F. wherein the adhesive comprises an amorphous poly-alpha-olefin polymer having a cold crystallization temperature; wherein the adhesive has a needle penetration number of (i) 8 to 50 dmm after 1 hour conditioning at 77° F., (ii) 10 to 45 dmm after 4 hour conditioning at 77° F., and (iii) 10 to 40 dmm after 24 hour conditioning at 77° F.; and wherein the pellets have an average percent deformation, (d0-d1)/d0×100%, less than 40%, where d0 is an initial diameter and d1 is a diameter measured after applying a weight of 70 g for one minute.