Patent ID: 7807255

Claim:
A heat-shrinkable opaque white film comprising a core layer; and white back and front layers, wherein the core layer comprises carbon black as a black colorant and the amount of carbon black is 0.01 to 3 percent by weight based on the total weight of the core layer, wherein each of the white front layer and the white back layer independently comprises titanium dioxide as a white colorant, and the content of titanium dioxide is 10 to 40 percent by weight of the total weight of each layer, wherein each of the front layer, the core layer, and the back layer independently is a heat-shrinkable film layer; wherein the thickness of the core layer is 5% to 30% of the total thickness of the heat-shrinkable opaque film; wherein the film has a transmission factor to light at wavelengths of 380 to 500 nm of 5% or less; wherein the heat-shrinkage percentage of the film is about 20% to about 90% when the film is immersed in hot water at 90° C. for ten seconds; and wherein the W-value of the surface of the heat-shrinkable films is 75 or more.