US4643122A — Diffusion controlled security tags

Claim 1

Independent Claim 84 words

A diffusion-controlled security tag comprising a carrier and a solution of a compound which changes color upon evaporation of the solvent forming said solution, said carrier being impregnated with said solution and being completely enclosed within a barrier film, said barrier film limiting the rate of diffusion of said solvent from said carrier such that a change in the color of said compound indicates that an object with which said tag is associated has been subjected to tampering or adverse storage time or temperature.

Claim 2

Dependent Claim 84 words

A diffusion-controlled security tag comprising a carrier and a solution of a compound which changes color upon evaporation of the solvent forming said solution, said carrier being impregnated with said solution and being completely enclosed within a barrier film, said barrier film limiting the rate of diffusion of said solvent from said carrier such that a change in the color of said compound indicates that an object with which said tag is associated has been subjected to tampering or adverse storage time or temperature.

Claim 3

Dependent Claim 13 words

The diffusion-controlled security tag of claim 1 wherein said carrier is a paper.

Claim 4

Dependent Claim 29 words

The diffusion-controlled security tag of claim 2 wherein said carrier is filled with a solution of an organic or inorganic salt of a transition metal in a polar solvent.

Claim 5

Dependent Claim 15 words

The diffusion-controlled security tag of claim 3 wherein said salt is a cobalt II salt.

Claim 6

Dependent Claim 15 words

The diffusion-controlled security tag of claim 3 wherein said salt is a copper II salt.

Claim 7

Dependent Claim 14 words

The diffusion-controlled security tag of claim 3 wherein said solvent is acetone or acetonitrile.

Claim 8

Dependent Claim 40 words

The diffusion-controlled security tag of claim 2 wherein said carrier is filled with a solution of a compound which exists in predominantly one form in solution and another form when said compound is in a dry state on said carrier.

Claim 9

Dependent Claim 13 words

The diffusion-controlled security tag of claim 7 wherein said compound is Rhodamine B.

Claim 10

Dependent Claim 13 words

The diffusion-controlled security tag of claim 1 wherein said carrier is a paper.

Claim 11

Dependent Claim 29 words

The diffusion-controlled security tag of claim 9 wherein said carrier is filled with a solution of an organic or inorganic salt of a transition metal in a polar solvent.

Claim 12

Dependent Claim 15 words

The diffusion-controlled security tag of claim 10 wherein said salt is a cobalt II salt.

Claim 13

Dependent Claim 15 words

The diffusion-controlled security tag of claim 10 wherein said salt is a copper II salt.

Claim 14

Dependent Claim 14 words

The diffusion-controlled security tag of claim 12 wherein said solvent is acetone or acetonitrile.

Claim 15

Dependent Claim 40 words

The diffusion-controlled security tag of claim 10 wherein said carrier is filled with a solution of a compound which exists in predominantly one form in solution and another form when said compound is in a dry state on said carrier.

Claim 16

Dependent Claim 13 words

The diffusion-controlled security tag of claim 14 wherein said compound is Rhodamine B.

Claim 17

Dependent Claim 13 words

The diffusion-controlled security tag of claim 1 wherein said barrier film is polyethylene.

Claim 18

Dependent Claim 14 words

The diffusion-controlled security tag of claim 1 wherein said barrier film is polyvinylidene chloride.

Claim 19

Independent Claim 77 words

A method for monitoring the storage of a perishable item which comprises the steps of: associating a security tag with said item such that said tag is subjected to essentially the same storage conditions as said item, said tag comprising a carrier containing a solution which undergoes a color change upon evaporation of the solvent, and examining said tag for a color change which indicates that said tag has been subjected to tampering or adverse storage conditions.

Claim 20

Independent Claim 77 words

A method for monitoring the storage of a perishable item which comprises the steps of: associating a security tag with said item such that said tag is subjected to essentially the same storage conditions as said item, said tag comprising a carrier containing a solution which undergoes a color change upon evaporation of the solvent, and examining said tag for a color change which indicates that said tag has been subjected to tampering or adverse storage conditions.

Claim 21

Dependent Claim 16 words

The method of claim 18 wherein said tag is enveloped in a diffusion limiting barrier film.

Claim 22

Dependent Claim 11 words

The method of claim 18 wherein said carrier is a paper.

Claim 23

Dependent Claim 24 words

The method of claim 20 wherein said carrier is filled with a solution of a salt of a transition metal in a polar solvent.

Claim 24

Dependent Claim 39 words

The method of claim 18 wherein said carrier is filled with a solution of a compound which exists in predominantly one form in solution and another isomeric form when said compound is in a dry state on said carrier.

Claim 25

Dependent Claim 38 words

The method of claim 18 wherein said solution is microencapsulated in a barrier film which limits the rate of diffusion of said solvent such that a change in the color of said solution occurs after a predetermined time.

Claim 26

Dependent Claim 68 words

A tamper-indicating, sealed container comprising a carrier therein and a solution of a compound which changes color upon evaporation of the solvent, said carrier being impregnated or otherwise filled with said solution, and said sealed container maintaining vapor pressure of said solvent such that when the seal on said container has been broken evaporation of the solvent is accompanied by a change in the color of said carrier.

Claim 27

Dependent Claim 68 words

A tamper-indicating, sealed container comprising a carrier therein and a solution of a compound which changes color upon evaporation of the solvent, said carrier being impregnated or otherwise filled with said solution, and said sealed container maintaining vapor pressure of said solvent such that when the seal on said container has been broken evaporation of the solvent is accompanied by a change in the color of said carrier.

Claim 28

Dependent Claim 76 words

A diffusion-controlled security tag comprising a carrier and a microencapsulated solution of a compound which changes color upon evaporation of the solvent forming said solution, said solution being microencapsulated in a barrier film which limits the rate of diffusion of said solvent from said solution such that a change in the color of said compound indicates that an object with which said tag is associated has been subjected to tampering or adverse storage time or temperature.

Claim 29

Dependent Claim 76 words

A diffusion-controlled security tag comprising a carrier and a microencapsulated solution of a compound which changes color upon evaporation of the solvent forming said solution, said solution being microencapsulated in a barrier film which limits the rate of diffusion of said solvent from said solution such that a change in the color of said compound indicates that an object with which said tag is associated has been subjected to tampering or adverse storage time or temperature.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-02-16	1990-08-18	1991-02-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-02-16	1994-08-18	1995-02-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-02-16	1998-08-18	1999-02-17	$7700.00	Window Closed / Lapsed

Diffusion controlled security tags

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