| 摘要 |
<p>A polyolefin film for stretch packaging which has a layer consisting mainly of the following resin (A) and has a storage elastic modulus (E') as determined by dynamic viscoelastometry at a frequency of 10 Hz and a temperature of 20 °C of 5.0x108 to 5.0x10?9 dyn/cm2¿ and a loss tangent (tan δ) of 0.2 to 0.8. (A) A flexible polypropylene resin which satisfies the following (1) to (3) and has such regulated stereoregularity that the content of (mmmm+rrrr) as determined from a 13C-NMR spectrum is 30 to 70 %: (1) to have a glass transition temperature of -15 °C or higher when heated with a differential scanning calorimeter at a rate of 10 °C/min; (2) to have a quantity of heat of crystallization of 10 to 60 J/g when cooled with a differential scanning calorimeter from 200 °C to room temperature at a rate of 10 °C/min after having been heated to 200 °C at a rate of 10 °C/min through crystal fusion and held at 200 °C for 5 minutes; and (3) to have an MFR (JIS K 7210, 230 °C, 2.16-kg load) of 0.4 to 40 g/10 min.</p> |
