Polymer-dispersed liquid crystal material and process
AssigneeFujitsu Limited
InventorDavid B. Chung
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Abstract
The present invention provides an improved liquid crystal material comprising a liquid crystal material dispersed in a polymer matrix. The polymeric matrix can be a thermal-based system such as an epoxy-based thermal polymeric system or a UV-curable system such as an acrylate-based polymeric system. The polymeric matrix has a crosslinking density which minimizes the driving voltage while maintaining a good contrast ratio. A process using dynamic mechanical analyzer (DMA) testing identifies a T.sub.g and crosslinking density which are employed to determine the optimum degree of crosslinking.
Claims1
A method of making a liquid crystal polymeric material comprising a liquid crystal material dispersed in a polymeric matrix selected from the group consisting of epoxy-based polymer and an acrylate-based polymer, said method comprising:
- (a) mixing crosslinking agent with the polymeric material to form a prepolymer, the ratio of polymeric material to crosslinking agent being less than or greater than the stoichiometric ratio thereof;
- (b) degassing the prepolymer to form a degassed prepolymer;
- (c) adding liquid crystal material and a spacer to the degassed prepolymer form a mixture;
- (d) degassing the mixture to form a degassed mixture;
- (e) applying the degassed mixture as a thin film;
- and
- (f) curing said thin film to form said liquid crystal polymeric material.
Dependencies are inferred from the claim text.