Temperature measuring device of a liquid crystal laminate

• US 4,064,872 A
• Filed: 09/02/1976
• Issued: 12/27/1977
• Est. Priority Date: 09/02/1976
• Status: Expired due to Term

• Current Assignee: Medical Indicators
• Original Assignee: Ashley-Butler Incorporated
• Inventors: Caplan, Sandor
• Primary Examiner(s): Ives, P. C.
• Application Number:
  US05/719,730
• Time in Patent Office: 481 Days
• Field of Search: 428/518, 428/515, 428/1, 428/354, 428/461, 428/72, 428/178, 428/179, 350/160 LC, 252/299, 73/356, 128/2 H
• US Class Current: 374/162
• CPC Class Codes: B41M 5/281 using liquid crystals only
• CPC Class Codes: C09K 2323/057 Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• CPC Class Codes: G01K 11/165 of organic liquid crystals
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/234 including elements cooperating to form cells
• CPC Class Codes: Y10T 428/24661 Forming, or cooperating to form cells
• CPC Class Codes: Y10T 428/24669 Aligned or parallel nonplanarities
• CPC Class Codes: Y10T 428/2848 Three or more layers
• CPC Class Codes: Y10T 428/31692 Next to addition polymer from unsaturated monomers

Abstract

Device for measuring temperature differentials on mammalian skin surfaces comprising separate dots of liquid crystals, sealed in a grid pattern between thin, performed, flexible films.

Claims

1. A temperature measuring device of high sensitivity and stability comprising a plurality of separate dots of liquid crystals which change color in a selected temperature range, sandwiched between two thin preformed, self-supporting films of heat sealable sheet material containing up to 500 mg per ream of monomeric components of solvents which are reactive with or soluble in the liquid crystal, a bottom opaque film and a top polymer film through which the color changes in the liquid crystals can be observed, the two films being sealed together in a grid pattern along narrow seal lines to form a multiplicity of separate cells, each cell containing a dot of liquid crystal.

2. A device of claim 1 in which the cells are square shaped.

3. A device of claim 1 in which the seal lines are heat seal lines.

4. A device of claim 1 in which the liquid crystals comprise a mixture of 46% by weight oleyl cholesteryl carbonate and 54% by weight cholesteryl nonanoate.

5. A device of claim 1 in which the liquid crystals comprise a mixture of 49% by weight oleyl cholesteryl carbonate and 51% by weight cholesteryl nonanoate.

6. A device of claim 1 in which the liquid crystals comprise a mixture of 52% oleyl cholesteryl carbonate and 48% cholesteryl nonanoate.

7. A device of claim 1 containing up to 50 mg per ream of components which are reactive with respect to or soluble in the liquid crystal.

8. A device of claim 1 wherein the top and bottom films each comprise polyethylene terephthalate coated on the inner surface with heat sealable polyvinylidene chloride.

9. A device of claim 1 wherein the top and bottom films each comprise polyethylene terephthalate coated on the inner surface with heat sealable polyvinyl chloride.

10. A device of claim 1 in which the bottom film comprises polypropylene laminated on its interior surface with aluminum foil.

11. A device of claim 1 in which the bottom film is coated on its outer surface with pressure sensitive adhesive.

12. A device of claim 1 containing from 40 to 400 cells per square inch.

13. A device of claim 2 containing 100 cells per square inch.