Polymer dispersed liquid crystal films formed by electron beam curing

• US 5,021,188 A
• Filed: 12/28/1989
• Issued: 06/04/1991
• Est. Priority Date: 09/22/1989
• Status: Expired due to Term

• Current Assignee: Brown University
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Smith, George W., Vaz, Nuno A.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Treanor, Richard
• Application Number:
  US07/458,466
• Time in Patent Office: 523 Days
• Field of Search: 252/299.01, 252/299.5, 350/347 V, 350/347 R, 522/74, 522/75, 522/79, 522/83
• US Class Current: 252/299.5
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: Y10S 359/90 Methods

Abstract

Optically responsive films comprising birefringent nematic and/or birefringent chiral nematic liquid crystal microdroplets dispersed in electron beam cured polymeric reaction products are disclosed.

Claims

1. A method for making a film containing microdroplets of a birefringent nematic and/or birefringent chiral nematic liquid crystal material dispersed in a polymer film comprising:

mixing a liquid crystal material with the electron-beam curable liquid precursor mixture, said electron-beam curable liquid precursor mixture comprising a mercaptan activated allyl compound; and

thereafter

curing the mixture in the form of a film with an electron beam to thereby form a cured polymer matrix having therein droplets of liquid crystal material displaying positive dielectric anisotropy and/or positive diamagnetic anisotropy.

2. A method for making a film containing microdroplets of a birefringent nematic and/or birefringent chiral nematic liquid crystal material dispersed in a polymer film comprising:

mixing a liquid crystal material with the electron beam precursor mixture comprising triallyl isocyanurate and pentaerythritol tetrakis(2-mercapto-propanoate); and

thereafter

curing the mixture in the form of a film with a focused electron beam to thereby form a cured polymer matrix which is a reaction product of said precursors containing dispersed therein droplets of liquid crystal material displaying positive dielectric anisotropy and/or positive diamagnetic anisotropy.