Process for forming a multilayer film and the film formed therefrom
In one embodiment, the process for forming a multilayer film comprises disposing a supportive layer adjacent to an imprinting layer to form a multilayer film and imprinting microstructures in the imprinting layer as the multilayer film passes between a heated roller and a compression roller. The multilayer film is free of a removable carrier layer. The supportive layer has a supportive layer glass transition temperature that is greater than or equal to about 15° C. higher than the imprinting layer glass transition temperature and/or the supportive layer has a supportive layer melting temperature that is greater than or equal to about 15° C. higher than an imprinting layer melting temperature. The imprinting temperature is lower than the supportive layer melting temperature.
1 . A process for forming a multilayer film, comprising:
disposing a supportive layer adjacent to an imprinting layer to form a multilayer film;
imprinting microstructures in the imprinting layer at an imprinting temperature as the multilayer film passes between a heated roller and a compression roller, wherein the multilayer film is free of a removable carrier layer; and
wherein the supportive layer has a supportive layer glass transition temperature that is greater than or equal to about 15° C. higher than the imprinting layer glass transition temperature and/or the supportive layer has a supportive layer melting temperature that is greater than or equal to about 15° C. higher than an imprinting layer melting temperature; and
wherein the imprinting temperature is lower than both the supportive layer melting temperature and the supportive layer glass transition temperature.
2 . The process of claim 1 , wherein disposing the supportive layer adjacent to the imprinting layer further comprises co-extruding the imprinting layer and the supportive layer to form the multilayer film.
3 . The process of claim 2 , further comprising
passing the co-extruded imprinting layer and supportive layer through a nip between calendering rolls;
cooling the co-extruded imprinting layer and supportive layer; and
disposing a texture on a second side of the supportive layer opposite the imprinting layer.
4 . The process of claim 1 , wherein disposing the supportive layer adjacent to the imprinting layer further comprises
forming the supportive layer with a desired surface texture on a second side;
forming the imprinting layer; and
disposing the imprinting layer adjacent to a first side of the supportive layer.
5 . The process of claim 4 , further comprising disposing a third layer between the imprinting layer and the supportive layer.
6 . The process of claim 1 , wherein the supportive layer glass transition temperature is greater than or equal to about 30° C. higher than the imprinting layer glass transition temperature.
7 . The process of claim 6 , wherein the supportive layer glass transition temperature is greater than or equal to about 45° C. higher than the imprinting layer glass transition temperature.
8 . The process of claim 1 , wherein the imprinting layer glass transition temperature is less than or equal to about 115° C. and the supportive layer glass transition temperature is about 135° C.
9 . The process of claim 8 , wherein the imprinting layer glass transition temperature is about 90° C. to about 105° C. and the supportive layer glass transition temperature is about 140° C. to about 150° C.
10 . The process of claim 9 , wherein the imprinting layer comprises polycarbonate-polyester copolymer, and wherein the supportive layer comprises polycarbonate.
11 . The process of claim 1 , wherein the supportive layer melting temperature is greater than or equal to about 30° C. higher than the imprinting layer melting temperature.
12 . The process of claim 6 , wherein the supportive layer melting temperature is greater than or equal to about 45° C. higher than the imprinting layer melting temperature.
13 . The process of claim 1 , wherein the supportive layer physically contacts the compression roller.
14 . The process of claim 1 , wherein the imprinting temperature is greater than or equal to 10° C. lower than both the supportive layer melting temperature and the supportive layer glass transition temperature.
15 . The process of claim 14 , wherein the imprinting temperature is greater than or equal to 20° C. lower than both the supportive layer melting temperature and the supportive layer glass transition temperature.
16 . A process for forming a multilayer film, comprising:
heating an imprinting layer to an imprinting layer temperature; and
imprinting microstructures in the imprinting layer to form a multilayer film comprising the imprinting layer and a supportive layer;
wherein a supportive layer physically contacts the compression roller during processing and has a supportive layer glass transition temperature that is greater than or equal to about 15° C. higher than the imprinting layer glass transition temperature and/or the supportive layer has a supportive layer melting temperature that is greater than or equal to about 15° C. higher than an imprinting layer melting temperature.
17 . The process of claim 16 , wherein the imprinting temperature is greater than or equal to 20 ° C. lower than both the supportive layer melting temperature and the supportive layer glass transition temperature.
18 . The process of claim 16 , wherein during imprinting, the multilayer film consists of the imprinting layer, the supportive layer, and optionally a layer therebetween.