WORKABILITY IMPROVING METHOD FOR POLYMER WITH ULTRA-LOW MELTING VISCOSITY

摘要

PROBLEM TO BE SOLVED: To produce an olefin polymer having a specific low melt viscosity by adding a free radical generating agent to a specific olefin polymer raw material and heating this raw material to crack the same and pelletizing the cracked raw material by a pelletizer. SOLUTION: An olefin polymer main material of which the melt index measured under a condition E of ASTM 1238 (190 deg.C, 2.16g) is about 0.2-100 δg/min is supplied to a main extruder. A first mixture to which a free radical generating agent (peroxide) is added in an amt. capable of forming a low viscosity polymer without generating mechanical destruction in the first stage of the main extruder is cracked. Next, a mixture of about 0.1-100 wt.% of a peroxide and about 0-99.9 wt.% of the polymer raw material is prepared in second and third stages. This raw material mixture is sent to a pelletizer to be pelletized to produce an olefin polymer of which the melt viscosity measured at 350 deg.F by a Brookfield viscometer according to ASTM D2556 is about 300,000 cps or less.