Polymer packaging material for liquid crystal cell

• US 4,456,638 A
• Filed: 11/01/1983
• Issued: 06/26/1984
• Est. Priority Date: 04/06/1981
• Status: Expired due to Term

• Current Assignee: Polytronix Inc.
• Original Assignee: Polytronix Inc.
• Inventors: Petcavich, Robert J.
• Primary Examiner(s): MCCAMISH, MARION E
• Application Number:
  US06/547,771
• Time in Patent Office: 238 Days
• Field of Search: 428/1
• US Class Current: 428/1.2
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film

Abstract

A twisted nematic liquid crystal material is sandwiched between two electrode carrying polymer film or sheet substrates in a liquid crystal display assembly. The substrate material preferably is a semi-crystalline aromatic heterochain polymer characterized by a glass transition point (T_g) of at least 90° C. and devoid of secondary transitions in the -50° C. to +80° C. range. The crystallinity of the polymer material is controlled so that the crystallite size in the polymer material is substantially smaller than the wave length of visible light (350-750 micrometers). In a preferred embodiment, an optically isotropic top substrate is formed by a sheet of amorphous cast thermosetting acrylic resin and the lower substrate is formed by a flexible sheet of semi-crystalline aromatic heterochain polymer.

Claims

1. In a field effect liquid crystal display cell having liquid crystal material confined between a pair of substrates, at least one of said substrates including an electrode mounted thereon, said at least one substrate being a polymer film or sheet substrate characterized by:

(1) a glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C.;

(2) a coefficient of thermal expansion matched with the electrode coefficient of thermal expansion;

(3) being an inert plastic having a crystallinity of twenty percent or more;

(4) having an ultraviolet stabilizer in the substrate;

(5) having an hydrophobic polymer for water resistance; and

(6) the chemical repeating units of the substrate being non-interactive with visible light.

2. The field effect liquid crystal display cell of claim 1 wherein the substrate having the glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C. is provided by adjusting the substrate polymer chain microstructure isotactic, atactic, or syndiotactic placements of the monomer repeating units.

3. The field effect liquid crystal display cell as defined in claim 1, wherein said polymer film or sheet is selected from the group comprising:

polyacrylonitrile, acrylonitrile-butadiene-styrene polymer, cellulose propionate, ethyl cellulose, poly(ethylene-co-chlorotrifluoroethylene), poly(ethylene-co-tetrafluoroethylene), fluorinated poly(ethylene-co-propylene), poly(chlorotrifluorethylene), poly (tetrafluoroethylene), poly(vinyl fluoride), poly(vinylidene fluoride), poly-(vinylidene chloride-co-vinyl chloride), nylon 6, 11, 12, polyrethane, polydiorganosiloxane, cast thermoset acrylic, poly(methylmethacrylate), poly(2,2-bis-4'"'"' phenylene propane carbonate), poly(ethyleneglycol-co-dimethylterephthalate), poly-4-methyl-pent-1-ene, polyolefin, poly(phenylenesulfide), poly(sulfone), poly(ethersulfone), polyimide, and poly(oxyethyleneoxyterephthaloyl), and allyl carbonate.

4. In a field effect liquid crystal display cell having liquid crystal material confined between a pair of substrates, and at least one of said substrates including an electrode mounted thereon, said at least one substrate being a polymer film or sheet substrate characterized by:

(1) having a glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C.;

(2) having a coefficient of thermal expansion matched with the electrode coefficient of thermal expansion;

(3) including a chemically resistant overcoat on the substrate;

(4) having an ultraviolet stabilizer included in the substrate;

(5) incorporating a hydrophobic polymer for water resistance; and

(6) being the chemical repeating units of the substrate non-interactive with visible light.

5. The field effect liquid crystal display cell as defined in claim 4 wherein said overcoat is selected from a group comprising chemical resistant thermosetting silicone, epoxy or urethane.

6. The field effect liquid crystal display cell as defined in claim 4, wherein said polymer film or sheet is selected from the group comprising:

polyacrylonitrile, acrylonitrile-butadiene-styrene polymer, cellulose propionate, ethyl cellulose, poly(ethylene-co-chlorotrifluoroethylene), poly(ethylene-co-tetrafluoroethylene), fluorinated poly(ethylene-co-propylene), poly(chlorotrifluorethylene), poly(tetrafluoroethylene), poly(vinyl fluoride), poly(vinylidene fluoride), poly-(vinylidene chloride-co-vinyl chloride), nylon 6, 11, 12, polyrethane, polydiorganosiloxane, cast thermoset acrylic, poly(methylmethacrylate), poly(2,2-bis 4'"'"' phenylene propane carbonate), poly(ethyleneglycol-co-dimethylterephthalate), poly-4-methyl-pent-1-ene, polyolefin, poly(phenylenesulfide), poly(sulfone), poly(ethersulfone), polyimide, and poly(oxyethyleneoxyterephthaloyl), and allyl carbonate.

7. In a field effect liquid crystal display cell having liquid crystal material confined between a pair of substrates, and at least one of said substrates including an electrode mounted thereon, said at least one substrate being a polymer film or sheet substrate characterized by:

(1) having a glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C.;

(2) having a coefficient of thermal expansion matched with the electrode coefficient of thermal expansion;

(3) being an inert plastic having a crystallinity of twenty percent or more;

(4) being a polymer that does not interact with ultraviolet radiation;

(5) incorporating a hydrophobic polymer for water resistance; and

(6) having the chemical repeating units of the substrate non-interactive with visible light.

8. The field effect liquid crystal display cell as defined in claim 7, wherein said polymer film or sheet is selected from the group comprising:

polyacrylonitrile, acrylonitrile-butadiene-styrene polymer, cellulose propionate, ethyl cellulose, poly(ethylene-co-chlorotrifluoroethylene), poly(ethylene-co-tetrafluoroethylene), fluorinated poly(ethylene-co-propylene), poly(chlorotrifluoroethylene), poly (tetrafluoroethylene), poly(vinyl fluoride), poly(vinylidene fluoride), poly-(vinylidene chloride-co-vinyl chloride), nylon 6, 11, 12, polyrethane, polydiorganosiloxane, cast thermoset acrylic, poly(methylmethacrylate), poly(2,2-bis 4'"'"' phenylene propane carbonate), poly(ethyleneglycol-co-dimethylterephthalate), poly-4-methyl-pent-1-ene, polyolefin, poly(phenylenesulfide), poly(sulfone), poly(ethersulfone), polyimide, and poly(oxyethyleneoxyterephthaloyl), and allyl carbonate.

9. In a field effect liquid crystal display cell having twisted nematic liquid crystal material confined between a pair of substrates, and at least one of said substrates including an electrode mounted thereon, said at least one substrate being a polymer film or sheet substrate characterized by:

(1) having a glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C.;

(2) having a coefficient of thermal expansion matched with the electrode coefficient of thermal expansion;

(3) being an inert plastic having a crystallinity of twenty percent or more;

(4) having an ultraviolet stabilizer included in the substrate;

(5) having a high degree of crystallinity for water resistance; and

(6) having the chemical repeating units of the substrate non-interactive with visible light.

10. The field effect liquid crystal display cell as defined in claim 9, wherein said polymer film or sheet is selected from the group comprising:

polyacrylonitrile, acrylonitrile-butadiene-styrene polymer, cellulose propionate, ethyl cellulose, poly(ethylene-co-chlorotrifluoroethylene), poly(ethylene-co-tetrafluoroethylene), fluorinated poly(ethylene-co-propylene), poly(chlorotrifluoroethylene), poly(tetrafluoroethylene), poly(vinyl fluoride), poly(vinylidene fluoride), poly-(vinylidene chloride-co-vinyl chloride), nylon 6, 11, 12, polyrethane, polydiorganosiloxane, cast thermoset acrylic, poly(methylmethacrylate), poly(2,2-bis 4'"'"' phenylene propane carbonate), poly(ethyleneglycol-co-dimethylterephthalate), poly-4-methyl-pent-1-ene, polyolefin, poly(phenylenesulfide), poly(sulfone), poly(ethersulfone), polyimide, and poly(oxyethyleneoxyterephthaloyl), and allyl carbonate.

11. In a field effect liquid crystal display cell having twisted nematic liquid crystal material confined between a pair of substrates, and at least one of said substrates including an electrode mounted thereon, said at least one substrate being a polymer film or sheet substrate characterized by:

(1) having a glass transition point and melting point of 80°

C. or higher with no secondary transitions between -50°

C. and +80°

C.;

(2) having a coefficient of thermal expansion matched with the electrode coefficient of thermal expansion;

(3) being an inert plastic having a crystallinity of twenty percent or more;

(4) having an ultraviolet stabilizer included in the substrate;

(5) incorporating a hydrophobic polymer for water resistance; and

(6) being isotropic.

12. The field effect liquid crystal display cell as defined in claim 11, wherein said polymer film or sheet is selected from the group comprising:

polyacrylonitrile, acrylonitrile-butadiene-styrene polymer, cellulose propionate, ethyl cellulose, poly(ethylene-co-chlorotrifluoroethylene), poly(ethylene-co-tetrafluoroethylene), fluorinated poly(ethylene-co-propylene), poly(chlorotrifluorethylene), poly(tetrafluoroethylene), poly(vinyl fluoride), poly(vinylidene fluoride), poly-(vinylidene chloride-co-vinyl chloride), nylon 6, 11, 12, polyrethane, polydiorganosiloxane, cast thermoset acrylic, poly(methylmethacrylate), poly(2,2-bis 4'"'"' phenylene propane carbonate), poly(ethyleneglycol-co-dimethylterephthalate), poly-4-methyl-pent-1-ene, polyolefin, poly(phenylenesulfide), poly(sulfone), poly(ethersulfone), polyimide, and poly(oxyethyleneoxyterephthaloyl), and allyl carbonate.