Biaxially oriented polylactic acid film with reduced noise level

摘要

Described are biaxially oriented polylactic acid (BOPLA) films with a novel formulation that exhibits a softer feel and quieter sound, without jeopardizing film making stability. The films can be used, for example, in packaging applications. The films can be metallized, or combined with barrier coatings or layers, for improved gas barrier properties particularly for moisture vapor transmission barrier desired in packaging applications. The films can also be printing films for packaging applications and may be transparent or matte in appearance. The films have characteristics that are beneficial to converting processes, are economical, and maintain bio-compostability similar to typical BOPLA films.

主权项

1. A biaxially oriented polylactic acid film comprising a quiet layer comprising polylactic acid (PLA) polymer, at least one elastomer E, and a biodegradable polymer A comprising polyhydroxybutyrate-valerate, polybutylene-adipate-co-terephthalate, polybutylene-succinate, polybutylene-succinate-adipate, or PH(R)A R=C2-C10, wherein the quiet layer is a core layer and complies with the following conditions:
60%≦wt %(PLA)≦90% Tg(A)≦0° C. 20%≦wt %(A)≦40% 1%≦wt %(E)≦10%in which,
Tg (A) is a glass transition temperature of the biodegradable polymer A, wt % (A) is a weight % of the biodegradable polymer A in the quiet layer, wt % (PLA) is a weight % of polylactic acid in the quiet layer; wt % (E) is a weight % of the at least one elastomer E in the quiet layer; and wherein the heat shrinkage of the film is 10% or less at 120° C.×15 min in both a machine direction (MD) and a transverse direction (TD), a strength at break of the film is 7000 psi or more in both the MD and the TD direction, the polymer A forms a layered structure in the quiet layer and the at least one elastomer E exists in the layered structure, and the film complies with the following condition:
E0−E≧5 dBin which,
E0 is a noise level of a biaxially oriented polylactic acid film consisting essentially of polylactic acid (dB), E is a noise level of a biaxially oriented polylactic acid film with polymer A (dB).