EP0289141A2
Expired / Lapsed
EP
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Thermochromic jet ink
Assignee: Videojet Technologies Inc
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Filing: 1988-03-30
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Granted: —
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Expires: 2008-03-30
Abstract
Abstract A thermochromic ink composition suitable for ink jet printing operations, characterised in that it comprises a combination of at least one heat-resistant and at least one heat-sensitive dye, said heat sensitive dye being capable of undergoing decomposition upon exposure to a predetermined elevated temperature for a predetermined period of time so that the color of the ink changes to that of the heat-resistant dye.
Inventors
- 👤 Bruce Alan Lent
- 👤 Paul N. Elue
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 18:33
CPC Classifications
C; C09; C09D; C09D11/00; C09D11/50; C09D11/30; C09D11/32; C09D11/328; C09D11/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
64 words
A thermochromic ink composition suitable for ink jet printing operations, characterized in that it comprises a combination of at least one heat-resistant and at least one heat sensitive dye, said heat sensitive dye being capable of undergoing decomposition only upon exposure to an elevated temperature for a period of time so that the color of the ink changes to that of the heat-resistant dye.
Claim 2
Dependent Claim
64 words
A thermochromic ink composition suitable for ink jet printing operations, characterized in that it comprises a combination of at least one heat-resistant and at least one heat sensitive dye, said heat sensitive dye being capable of undergoing decomposition only upon exposure to an elevated temperature for a period of time so that the color of the ink changes to that of the heat-resistant dye.
Claim 3
Dependent Claim
60 words
An ink composition according to claim 1, wherein the two different dyes have vividly different colors and the heat sensitive dye is present in an amount from about 0.5 to about 2.5 weight percent, and the heat resistant dye is present in an amount from about 1.0 to about 4.0 weight percent, based on the total weight of the composition.
Claim 4
Dependent Claim
31 words
An ink composition according to claim 1 or 2, wherein the ink irreversibly changes color in response to a chosen thermal environment with or without the presence of water or steam.
Claim 5
Dependent Claim
41 words
An ink composition according to claim 1, 2 or 3, in which the heat-sensitive dye is capable of degrading, irreversibly, so that the ink is capable of visually registering a color change upon exposure to about 116°C. for about 15 minutes.
Claim 6
Dependent Claim
43 words
An ink composition according to any preceding claim, which has a viscosity from about 1.6 to about 7.0 centipoises at 25°C. , an electrical resistivity from about 50 to about 2000 ohm/cm, and a sonic velocity from about 1200 to about 1300 meters/sec.
Claim 7
Dependent Claim
26 words
An ink composition according to any preceding claim, which will undergo the said degradative color change when subjected to conditions of retorting, sterilizing, pasteurizing or autoclaving.
Claim 8
Dependent Claim
29 words
An ink composition according to any preceding claim, which when jet printed on bare tinplate or on polymeric coated tin or aluminum cans will quickly dry with good adhesion.
Claim 9
Dependent Claim
50 words
An ink composition according to any preceding claim, wherein the heat-resistant dye is selected from the group consisting of Solvent Red 33, Basic Violet 4, Solvent Blue 98, and Solvent Red 164 and the heat-sensitive dye is selected from the group consisting of Basic Green 4 and Solvent Yellow 56.
Claim 10
Dependent Claim
72 words
A method of indicating sterilization of an article which comprises applying a marking to the surface of said article utilizing the ink composition of claim 1 and exposing the marked article in a temperature/time dependant manner to an environment having a temperature of from about 116°C. to about 127°C. for a period of time of at least about 15 minutes, such that the said color change is effected visibly in said markings.
Claim 11
Dependent Claim
34 words
A method according to Claim 9, wherein said markings are applied by jet ink printing of said thermochromic ink composition and the exposure is to a temperature of about 116°C. for about 15 minutes.
References Cited (Backward Citations)
No citation records indexed.
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