High extinction polarizer films comprising liquid crystal polymeric moieties
AssigneeHoechst Celanese Corporation
InventorsMohammad Mortazavi, Hyun Nam Yoon, Chia-Chi Teng
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Abstract
This invention provides all organic high extinction polarizers based on blends of novel liquid crystalline polymers and suitable dichroic dyes. The invention further provides a process to prepare such polarizer films.
Claims24
An all organic polarizing film comprising a blend of (a) at least one film-forming, wholly aromatic thermotropic liquid crystal polymer and (b) at least one organic dichroic dye, and possessing an initial polarizing efficiency of at least 70% and a dichroic ratio of at least 5, with said liquid crystal polymer being a polyester which comprises repeat units corresponding to the formula:
- --[P.sup.1 ].sub.m --[P.sup.2 ].sub.n --[P.sup.3 ].sub.q --
- wherein P.sup.1, P.sup.2, and P.sup.3 represent monomeric moieties with P.sup.1 being an aromatic hydroxy carboxylic acid, P.sup.2 being an aromatic dicarboxylic acid, and P.sup.3 being a phenol, with m, n and q representing mole percent of the respective monomers ranging from 5-70 mole percent individually.
An all organic polarizing film comprising a blend of (a) at least one film-forming, wholly aromatic thermotropic liquid crystal polymer and (b) at least one organic dichroic dye, and possessing an initial polarizing efficiency of at least 70% and a dichroic ratio of at least 5, with said liquid crystal polymer being a polyesteramide which comprises repeat units corresponding to the formula:
- --[P.sup.1 ].sub.m --[P.sup.2 ].sub.n --[P.sup.3 ].sub.q --
- wherein P.sup.1, P.sup.2, and P.sup.3 represent monomeric moieties with P.sup.1 being an aromatic amino carboxylic acid, P.sup.2 being an aromatic dicarboxylic acid, and P.sup.3 being a phenol;
- with m, n and q representing mole percent of the respective monomers ranging from 5-70 mole percent individually.
An all organic high extinction polarizer film with high thermal and hygroscopic stability, comprising a blend of (a) a thermotropic liquid crystal polymer which comprises 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, terephthalic acid, 4,4'-dihydroxybiphenyl and resorcinol in a molar ratio 30:30:20:10:10 respectively, and (b) an organic dichroic dye, and possessing an initial polarizing efficiency of at least 70%, and a dichroic ratio of at least 5.
A process to prepare an all organic high extinction polarizer film, said process comprising:
- (a) bringing together a suitable liquid crystal polymer with one or more suitable dichroic dyes into a mix;
- (b) melt blending said mix to form an uniform blend at a temperature at about the melt temperature of said polymer;
- and
- (c) extruding said blend at about the melt temperature of said polymer in a suitable apparatus to form the polarizer film, with said liquid crystal polymer being a polyester or a polyesteramide, wherein said polyester comprises repeat units corresponding to the formula:
- --[P.sup.1 ].sub.m --[P.sup.2 ].sub.n --[P.sup.3 ].sub.q --
- wherein P.sup.1, P.sup.2, and P.sup.3 represent monomeric moieties with P.sup.1 being an aromatic hydroxy carboxylic acid, P.sup.2 being an aromatic dicarboxylic acid, and P.sup.3 being a phenol;
- and further wherein said polyesteramide comprises repeat units corresponding to the formula:
- --[P.sup.4 ].sub.m --[P.sup.5 ].sub.n --[P.sup.6 ].sub.q --
- wherein P.sup.4, P.sup.5, and P.sup.6 represent monomeric moieties with P.sup.4 being an aromatic amino carboxylic acid, P.sup.5 being an aromatic dicarboxylic acid, and P.sup.6 being a phenol;
- with m, n and q representing mole percent of the respective monomers ranging from 5-70 mole percent individually.
Dependencies are inferred from the claim text.