MULTILAYERED ARTICLES WITH LOW OPTICAL RETARDATION

摘要

A coextruded multilayered thermoplastic article including: a first layer with a first surface texture, wherein the first layer comprises a first transparent thermoplastic polymer having a first stress optical coefficient (Cm1) measured at 20° C. above the glass transition temperature of the first polymer; a second layer located comprising a second transparent thermoplastic polymer having a second stress optical coefficient (Cm2) measured at 20° C. above the glass transition temperature of the second matrix;wherein a relation between the first stress optical coefficient and the second stress optical coefficient is Cm2>4(Cm1) (Formula A) wherein the thickness of the first layer measured from the highest peaks of the first surface texture to the second side of the first layer is greater than 1.5 times Rz of the first surface texture but less than or equal to 75% of the total thickness of the article.

主权项

1. A coextruded multilayered thermoplastic article, comprising:
a first layer with a first side and a second side and with a first surface texture on the first side, wherein the first layer comprises a first transparent thermoplastic polymer having a first stress optical coefficient (Cm1) measured at 20° C. above the glass transition temperature of the first polymer; a second layer located adjacent the second side and comprising a second transparent thermoplastic polymer having a second stress optical coefficient (Cm2) measured at 20° C. above the glass transition temperature of the second matrix; wherein a relation between the first stress optical coefficient and the second stress optical coefficient is Formula (A)
Cm2>4(Cm1)   (Formula A) wherein the thickness of the first layer measured from the highest peaks of the first surface texture to the second side of the first layer is greater than 1.5 times Rz of the first surface texture but less than or equal to 75% of the total thickness of the article; wherein the second layer has a second layer thickness that is greater than or equal to 25% of the total thickness of the article; and wherein the optical retardation of the article is less than or equal to 150 nm.