US 2014/0265010 A1Published application

Method of preparing photochromic-dichroic films having reduced optical distortion

AssigneeTransitions Optical, Inc.

InventorsDavid Park, Anil Kumar

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Abstract

The present invention relates to a method of preparing a photochromic-dichroic film. The method includes forming a molten extrudate that includes a first molten thermoplastic layer that includes one or more photochromic-dichroic compounds, that is interposed between separate second and third outer molten thermoplastic layers. The molten extrudate is cooled so as to form a multilayer film that includes a first layer that includes one or more photochromic-dichroic compounds, that is interposed between separate second and third outer layers. The second and third outer layers are removed from the first layer of the multilayer film. The resulting sole first layer, which is retained, defines the photochromic-dichroic layer, which exhibits reduced or minimal optical distortion.

Claims20

Dependent claims

A method of preparing a photochromic-dichroic film comprising:

(a) forming a first molten thermoplastic composition comprising a first thermoplastic polymer and a photochromic-dichroic compound;
(b) forming a second molten thermoplastic composition comprising a second thermoplastic polymer;
(c) forming a third molten thermoplastic composition comprising a third thermoplastic polymer;
(d) introducing said first molten thermoplastic composition, said second molten thermoplastic composition, and said third molten thermoplastic composition into a die having a terminal slot;
(e) removing a molten extrudate from said terminal slot, said molten extrudate comprising,
(i) a first molten layer comprising said first molten thermoplastic composition,
(ii) a second molten layer comprising said second molten thermoplastic composition, and
(iii) a third molten layer comprising said third molten thermoplastic composition,
wherein said first molten layer is interposed between said second molten layer and said third molten layer;
(f) cooling said molten extrudate to form a multilayer film comprising a first layer formed from said first molten layer, a second layer formed from said second molten layer, and a third layer formed from said third molten layer, wherein said first layer is interposed between said second layer and said third layer;
and
(g) removing, from said first layer, said second layer and said third layer, and
retaining said first layer,
wherein said first layer defines said photochromic-dichroic film.

11 more elements

Dependencies are inferred from the claim text.