Microencapsulated liquid crystal having multidomains induced by the polymer network and method

• US 6,203,723 B1
• Filed: 03/12/1998
• Issued: 03/20/2001
• Est. Priority Date: 03/12/1998
• Status: Expired due to Term

• Current Assignee: Ying Yen Hsu
• Original Assignee: Ying Yen Hsu
• Inventors: Hsu, Ying Yen
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US09/042,394
• Time in Patent Office: 1,104 Days
• Field of Search: 252/299.01, 252/299.5, 252/299.1, 349/10, 349/86, 428/402.2, 428/402.24
• US Class Current: 252/299.01
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: C09K 2019/546 creating a polymeric network

Abstract

A liquid crystal material containing polymer network forming material is microencapsulated by a method utilizing an interfacial polymerization which creates a combination of polyurethane and polyurea polymers or melamine fromaldehyde or urea formaldehyde polymer which form the capsule walls surrounding the discrete liquid crystal droplets. The prepolymer of urethane acrylate and acrylate within the liquid crystal capsules is cured under UV light irradiation to form a web-like structure and induce the formation of polydomain configuration of nematic director. This allows to produce the display having faster switching property and showing significant lower threshold voltage.

Claims

1. A composition for use in preparing microencapsulated liquid crystal material, comprising (A) a liquid crystal;

(B) a capsule wall forming material including (1) a polyisocyanate, a water soluble polyol or a polyamine, or (2) a melamine fromaldehyde or a urea formaldehyde, and;

(C) a polymer network forming material including, a prepolymer of urethane acrylate, acrylate or ally derivative; and

(D) a photoinitiator, wherein the prepolymer of acrylate or ally derivative is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, di(ethylene glycol) diacrylate, di(ethylene glycol) dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetramethacrylate, 1,4-butanediol diacrylate, 1,4-buthanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tri(ethylene glycol) diacrylate, tri(ethylene glycol) dimethacrylate, bis(allyl carbonate), trimethylolpropane diallylether, 2,4,6-triallyoxy-1,3,5-triazine, epoxy acrylate, liquid crystal acrylate and mixtures thereof.