Reactivity control in substituted diacetylenic monomer shelf life monitoring systems

• US 6,924,148 B2
• Filed: 07/02/2003
• Issued: 08/02/2005
• Est. Priority Date: 07/02/2003
• Status: Active Grant

• Current Assignee: Temptime Corporation (Zebra Technologies Corporation)
• Original Assignee: Temptime Corporation (Zebra Technologies Corporation)
• Inventors: Prusik, Thaddeus
• Primary Examiner(s): Gakh, Yelena G.
• Application Number:
  US10/611,302
• Publication Number:
  US 20050003551A1
• Time in Patent Office: 762 Days
• Field of Search: 436/7, 422/56, 374/102, 374/104, 374/106
• US Class Current: 436/7
• CPC Class Codes: G01N 31/229 for investigating time/temperature history

Abstract

A product shelf life monitoring system comprising an active substituted diacetylenic monomer component indicator composition is responsive to an integral of varying temperature over time to effect a solid state polymerization in the active monomer which results in a visible change in color density or the like at a rate designed to closely approximate the degradation, or shelf life, of an associated foodstuff or medicament product. The reactivity of the monomer component upon which the time-temperature integral of the indicator composition, and thus the represented shelf life, primarily depends may be readily varied by refluxing a solution of the monomer in a selected solvent for a predetermined time prior to recrystallization of the monomer for incorporation into the indicator composition.

Claims

1. The method of varying the heat-induced solid state polymerization reactivity of a distinctively crystalline structured substituted diacetylenic monomer shelf life monitoring system composition, which method comprises:

a) providing a solution of said monomer component of a, in a first state of said reactivity at a temperature below the reflux temperature of said solution,

b) heating said solution to said reflux temperature in a reflux system,

c) continuing reflux of said solution for a predetermined time period, and

d) recrystallizing the solute from said refluxed solution to thereby yield said monomer component in a second state of said reactivity while having substantially retained said crystalline structure.

2. The method according to claim 1 wherein said reflux period extends up to about 45 minutes.

3. The method according to claim 1 wherein the solvent of said solution is selected from the group consisting of acetic acid and dimethyl formamide.

4. The method according to claim 3 wherein said reflux period extends from about one to 15 minutes.

5. The method according to claim 1 wherein said monomer component is selected from the group consisting of 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

6. The method according to claim 5 wherein said monomer component is selected from the group consisting of ethyl-, propyl-, and octyl-substituted 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

7. A product shelf life monitoring system composition comprising an active substituted diacetylenic monomer component derived by recrystallization from a refluxed solution of said component according to the method of claim 1.

8. A composition according to claim 7 wherein the monomer component of said refluxed solution is selected from the group consisting of 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

9. A composition according to claim 8 wherein the monomer component of said refluxed solution is selected from the group consisting of ethyl-, propyl-, and octyl-substituted 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

10. A composition according to claim 7 wherein the solvent of said solution is selected from the group consisting of acetic acid and dimethyl formamide.

11. A composition according to claim 10 wherein the period of reflux of said component solution extends from about one to 15 minutes.

12. A product shelf life monitoring system comprising a substrate surface bearing an active indicator composition responsive in a visible change under incident thermal energy to which an associated product is susceptible, said indicator composition comprising an active substituted diacetylenic monomer component derived by recrystallization from a refluxed solution of said component according to the method of claim 1.

13. A system according to claim 12 wherein said associated product is a foodstuff.

14. A system according to claim 12 wherein said associated product is a medicament.

15. A system according to claim 12 wherein the monomer component of said refluxed solution is selected from the group consisting of 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

16. A system according to claim 12 wherein the monomer component of said refluxed solution is selected from the group consisting of ethyl-, propyl-, and octyl-substituted 2,4-hexadiyn-1,6-bis(alkylurea) compounds and co-crystallized combinations thereof.

17. A system according to claim 16 wherein the solvent of said solution is selected from the group consisting of acetic acid and dimethyl formamide.

18. A system according to claim 17 wherein the period of reflux of said component solution extends from about one to 15 minutes.