| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject copolymer which has the highest flexibility up to now, excellent elastic recovery and good transparency, and can be used as a packing material by allowing the copolymer to satisfy specific relations. SOLUTION: This copolymer has (A) a styrene content of 3-50mol%, (B) a density ranging from 0.930-1.05g/cm<3> , (C) an intrinsic viscosity [η] of 0.2-0.5 calculated from the formula I from the relation of the reduced viscosity (ηsp/c (dl/g)) to the concentration (c (g/dl)), (D) the relation of the glass transition point (Tg ( deg.C)) measured with differential scanning calorimeter with the styrene content (St (mole %)) satisfies the formula II. In addition, it is preferred that (E) the relation of the elastic modulus (E (dyne/cm<2> )) with the styrene content satisfies the formula III. The objective effect can be expected by giving a copolymer in which ethylene and styrene are well copolymerized and their random distribution is excellent. |
