Disclosed are novel compositions for the preparation of void-containing
articles comprising a polymer matrix and a voiding agent The voiding
agent comprises at least one first polymer and at least one second
polymer, which are selected on the basis of physical properties such as
glass transition temperature, tensile modulus, melting point, surface
tension, and melt viscosity. Shaped articles such as sheet, film,
bottles, tubes, labels, and sleeves may prepared from these compositions.
Also disclosed are polyester shrink films prepared using a voiding agent
comprising a novel blend of cellulosic and olefinic polymers. The
resulting shrink films have better opacity, lower density, reduced shrink
force, and improved printability as compared with most standard voiding
agents. The films are useful for sleeve label and other shrink film
applications and their lower density allows them to be readily separated
from soft drink bottles, food containers and the like during recycling
operations.
