Patent ID: 11965069
Assignee: FAR EASTERN NEW CENTURY CORPORATION
Field: Other special machines (Mechanical engineering)
Classification: CPC C | IPC C

Claim 3:
4. The heat-shrinkable polyester film according to claim 1, which satisfies relationships of

Δnc≤10×10−3, and

Δnc=Δn×[1−(99° C. TD%/TDMax %)],

where
Δn represents a birefringence of said heat-shrinkable polyester film;
99° C. TD % represents a heat-shrinkability of said heat-shrinkable polyester film in a transverse direction, which is measured according to JIS Z1709 after immersing said heat-shrinkable polyester film in hot water at 99° C. for 10 seconds and then removing from the hot water; and
TDMax %=[(TDX−1)/TDX]×100%, in which TDX represents a stretch ratio of a sheet in the transverse direction in a process for forming said heat-shrinkable polyester film, said sheet being made of said polyester-forming resin composition.