Patent ID: 7306835
Filing Date: 2007-12-11
Classification: C08J,Y10S,Y10T

Abstract:
1. A thermo-shrinkable polyester film having an orientation angle of a molecular chain of the film in a range of from 0° to about ±10° relative to a main shrinkage direction; and a molecular orientation ratio (MOR) represented by the following Formula 2 in a range of from about 1.29 to about 2.5, wherein the orientation angle of the molecular chain is a rotation angle (θ) at which a microwave transmit intensity, I(θ), has a maximum value, the microwave transmit intensity being determined by the following Formula 1: Formula 1 Formula 2 wherein, I(θ) is a microwave transmit intensity at a rotation angle θ; I o is a microwave transmit intensity at a resonance point; I av is a mean microwave transmit intensities measured at each degree of rotation angles of 360 degrees; W o is a resonance angular frequency; W is an angular frequency; θ is a rotation angle; Q is a ratio of a resonance angular frequency to a half-wave width of a resonance curve (W o /ΔW); I max is a maximum value of microwave transmit intensity; and I min is a minimum value of microwave transmit intensity.