JP2003041021A5 - - Google Patents

Claims (7)

In heat shrinkable polyester film,
Of 100 mol% of the polyhydric alcohol component, 1,4-cyclohexanedimethanol component is 5 mol% or more,
A compound derived from a polymerization catalyst, at least one metal-containing compound for polymerization selected from a titanium compound, a manganese compound, a cobalt compound, a germanium compound, a tin compound, and an antimony compound;
An alkaline earth metal compound;
Containing a phosphorus compound,
A heat-shrinkable polyester film having the following properties (1) and (2).
(1) When a sample of a heat-shrinkable polyester film cut into a 10 cm × 10 cm square shape is dipped in hot water at 85 ° C. for 10 seconds, and then dipped in water at 25 ° C. for 10 seconds. (2) The amount of insoluble foreign matter having a particle size of 0.1 μm or more contained in 1 kg of film is caused by alkaline earth metal atom M ¹ and polymerization metal atom M ^{x in the} foreign matter. The total amount is 1 mg or less The content of alkaline earth metal atom M ^{2 in} the film is 40 ppm (mass basis) or more, the content of phosphorus atom is 20 ppm (mass basis) or more, and the content of metal atom M ^x for polymerization is 50 ppm (mass basis) or more. The heat-shrinkable polyester film according to claim 1. The heat-shrinkable polyester film according to claim 1 or 2, wherein a melt specific resistance value at a temperature of 275 ° C is 0.70 × 10 ⁸ Ω · cm or less. The heat shrinkable polyester according to any one of claims 1 to 3, wherein the atomic weight ratio (M ² / P) of the alkaline earth metal atom M ² and the phosphorus atom P in the film is 1.2 to 5.0. Film. The heat-shrinkable polyester film according to any one of claims 1 to 4, wherein a proportion of the 1,4-cyclohexanedimethanol in 100 mol% of the polyhydric alcohol component is 10 to 80 mol%. The heat-shrinkable polyester film according to any one of claims 1 to 5, which has an intrinsic viscosity of 0.66 dl / g or more. When producing polyester as a raw material for the heat-shrinkable polyester film according to claim 1, the esterification step is divided into three or more steps having different degrees of progress of esterification and oligomerization, and alkaline earth is added after the second step. A method for producing a polyester in which a phosphorus compound is added in a plurality of steps in a step after the step of adding an alkali metal compound and an alkaline earth metal compound is added, and the resulting ester and oligomer are polymerized.