TIME TEMPERATURE INDICATOR

• US 20110155043A1
• Filed: 06/15/2009
• Published: 06/30/2011
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: Freshpoint Quality Assurance Ltd.
• Original Assignee: Freshpoint Quality Assurance Ltd.
• Inventors: Salman, Husein, Gueta-Neyroud, Tal, Haarer, Dietrich
• Granted Patent: US 8,968,662 B2
• Time in Patent Office: Days
• US Class Current: 116/201
• CPC Class Codes: G01K 3/04 in respect of time

Abstract

The present invention is generally in the field of measuring and indicating techniques and relates to a time-temperature indicator and methods of manufacturing and use thereof. More specifically, the time-temperature indicator comprises at least one metal layer or metal containing layer, and in direct contact to the metal layer or to the metal containing layer at least one pad member affixed onto a pad carrier layer,

wherein the pad member comprises a pad made of an absorbent material and a dopant medium, whereby the dopant medium comprises a liquid medium or a viscous medium or a viscoelastic medium which is doped with a dopant that destroys the metal/metal containing layers such as an acid, a base or a salt or a photolatent acid or a photolatent base.

Claims

1. A time temperature indicator comprising a) at least one metal layer or metal containing layer, and in direct contact to the metal layer or to the metal containing layer b) at least one pad member affixed onto a pad carrier layer, wherein the pad member comprises a pad made of an absorbent material and a dopant medium, whereby the dopant medium comprises a liquid medium or a viscous medium or a viscoelastic medium which is doped with a dopant able to destroy the metal/metal containing layers.

2. A time temperature indicator according to claim 1, wherein the dopant is a salt.

3. A time temperature indicator according to claim 1, wherein the dopant is an acid.

4. A time temperature indicator according to claim 1, wherein the dopant is a base.

5. A time temperature indicator according to claim 1, wherein the dopant is a photolatent acid where the acid is released upon irradiation with light.

6. A time temperature indicator according to claim 1, wherein the dopant is a photolatent base where the base is released upon irradiation with light.

7. A time temperature indicator according to claim 1, wherein the dopant is added in a concentration of 1-20%.

8. The time temperature indicator according to claim 7, wherein the metal layer is a metal containing layer consisting of or based on inks based on metal pigment dispersions.

9. The time temperature indicator according to claim 7, wherein the metal layer is a polymer matrix containing metal particles.

10. The time temperature indicator according to claim 7, wherein the metal/metal containing layer comprises at least two sections of different thickness.

11. The time temperature indicator according to claim 7, wherein the metal layer is part of a resistor device.

12. The time temperature indicator according to claim 7, wherein the metal layer is part of a capacitive TTI device which is characterized by at least two conductive layers with a dielectric/insulating layer in between.

13. A method for producing the time temperature indicator as described in claim 1 comprising a) doping a pad by adding a liquid medium or a viscous medium or a viscoelastic medium which is doped with a salt solution, a liquid acid or a liquid base to the pad thus obtaining a reactive pad member, b) applying the reactive pad member of step a) on a carrier thus obtaining a reactive pad layer as one label;

c) applying a metal layer or a metal containing layer on a substrate thus obtaining a second label. d) activating by applying the pad layer of step b) onto the metal layer of step c.

14. A method for producing the time temperature indicator as described in claim 1 comprising a) doping a pad by adding a liquid medium or a viscous medium or a viscoelastic medium which is doped with a latent acid or a latent base thus obtaining a reactive pad member, b) activating the latent reactive pad member by irradiation with light thus obtaining a reactive pad member;

c) applying the pad member on a metal layer or a metal containing layer affixed on a substrate thus obtaining a label whereby placing one layer atop the other may be done either before activation or after or at the same time.

15. A method for the preparation of the doped pad member according to claim 13 comprising the steps of a) submerging the pad in the liquid dopant or pouring the dopant upon the pad, b) sticking the pad member on a suitable carrier thus obtaining a first label c) removing the excess dopant.

16. Use of the time temperature indicator according to claim 1 for monitoring storage temperatures of product packages and for detecting exceeded temperature limits.