Film and stretch packaging film

A film containing at least 5 wt % of an aromatic vinyl compound-ethylene random copolymer having an aromatic vinyl compound content of from 1 to less than 99.9% by molar fraction, having head-to-tail chain structures comprising at least two aromatic vinyl compound units and having the following characteristic:

• the alternating structure index λ represented by the following formula (i) is smaller than 70 and larger than 1:
• λ=A3/A2×100 (i)
• where A3 is the sum of areas of three peaks a, b and c attributable to an aromatic vinyl compound-ethylene alternating structure represented by the following formula (1′), obtained by 13C-NMR, and A2 is the sum of areas of peaks attributable to the main chain methylene and main chain methine carbon, as observed within a range of from 0 to 50 ppm by 13C-NMR using TMS as standard, 12
• wherein Ph is an aromatic group such as a phenyl group, and x is an integer of at least 2 representing the number of repeating units.

A stretch packaging film containing at least 5 wt % of an aromatic vinyl compound-ethylene random copolymer having an aromatic vinyl compound content of from 1 to 50% by molar fraction, having head-to-tail chain structures comprising at least two aromatic vinyl compound units, and comprising a structure represented by the following formula (2) as the main structure, whereby the index θ represented by the following formula (ii), is larger than 70:

• θ=A1/A2×100 (ii)
• where A1 is the sum of areas of peaks attributable to methine and methylene carbon α to ε in the following formula (2′) as observed within a range of from 0 to 50 ppm by 13C-NMR using TMS as standard, and A2 is the sum of areas of peaks attributable to the main chain methylene and methine carbon, as observed within a range of from 0 to 50 ppm by 13C-NMR using TMS as standard:
• 13
• wherein Ph is an aromatic group such as a phenyl group, xb is an integer of at least 2 representing the a number of repeating units, y is an integer of at least 1, which may be the same or different among the respective repeating units, and z is 0 or 1, which may be the same or different in the respective repeating units, 14
• wherein Ph is an aromatic group such as a phenyl group, xb is an integer of at least 2 representing the number of repeating units, y is an integer of at least 1, which may be the same or different in the respective repeating units, and z is 0 or 1, which may the same or different in the respective repeating units.