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US 4,661,305 AGranted
Method of marking a substrate using a markable thermochromic article
AssigneeRaychem Corporation
InventorWilliam D. Carlomagno
Life of this patent
Estimating the term…
Abstract
An article which in use is heated to an elevated utilization temperature comprises a thermochromic composition, which when heated to a transition temperature, provides a visible color change in less than about 5 seconds. The transition temperature is at least 30.degree. C. greater than the utilization temperature. To place visible indicia on the article, the article is heated to a temperature at least as great as the transistion temperature.
Claims33
A method for marking a substrate comprising the steps of:
- (a) placing on the substrate an article that is removable from the substrate until the article is heated to a temperature T1 of at least 100.degree. C., the article being non-removable from the substrate when the article is heated to T1, the article having a thermochromic composition on at least a portion of a visible surface thereof, the thermochromic composition providing a substnatially irreversible visible color change in less than about 5 seconds when heated to a transition temperature T2, T2 being a sufficient amount greater than T1 that the thermochromic composition does not change color when the article is heated to T1;
- (b) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 5 seconds so that only a portion of the thermochromic composition irreversibly changes color without affecting the removability of the article from the substrate;
- and
- (c) preventing the article from being removed from the substrate without changing the color of the thermochromic composition by heating substantially the entire article to at least T1 but less than T2.
1 more element
A method for placing indicia on an article comprising the steps of:
- (a) selecting an article that has a heat activated property that is activated at a temperature T1 of at least 100.degree. C., the article having a thermochromic composition on at least a portion of a surface thereof, the thermochromic composition providing a visible color change in less than about 5 seconds when heated to a transition temperature T2, T2 being a sufficient amount greater than T1 that the thermochromic composition does not change color when the article is heated to T1;
- (b) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 5 seconds so that only a portion of the thermochromic composition changes color without activating the heat activated property of the article;
- and
- (c) heating substantially the entire article to at least T1 but less than T2, the thermochromic composition not changing color.
1 more element
A method for marking a substrate comprising the steps of:
- (a) placing on the substrate a heat-recoverable, tubular, polymeric article that recovers when heated to a heat-recovery temperature T1, T1 being at least 100.degree. C., the article having a thermochromic paint comprising a thermochromic composition on at least a portion of its outer surface, the thermochromic composition providing a substantially irreversible visible color change in less than about 1 second when heated to a transition temperature T2, T2 being at least 30.degree. C. greater than T1, the thermochromic composition not changing color when the article is heated to T1;
- (b) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 1 second so that a portion of the thermochromic composition irreversibly changes color without recovering the article;
- and
- (c) recovering the article on the substrate without changing the color of the thermochromic composition by heating substantially the entire article to at least T1 but less than T2.
1 more element
A method for marking a substrate comprising the steps of:
- (a) placing on the substrate an article that is removable from the substrate until the article is heated to a temperature T1 of at least 100.degree. C., the article being non-removable from the substrate when the article is heated to T1, the article having a thermochromic composition on at least a portion of a visible surface thereof, the thermochromic composition providing a substantially irreversible visible color change in less than about 5 seconds when heated to a transition temperature T2, T2 being a sufficient amount greater than T1 that the thermochromic composition does not change color when the article is heated to T1;
- (b) preventing the article from being removed from the substrate without changing color of the thermochromic compostion by heating substantially the entire article to at least T1 but less than T2;
- and
- (c) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 5 seconds so that only a portion of the thermochromic composition irreversibly changes color.
1 more element
A method for placing indicia on an article comprising the steps of:
- (a) selecting an article that has a heat activated property that is activated at a temperature T1 of at least 100.degree. C., the article having a thermochromic composition on at least a portion of a surface thereof, the thermochromic composition providing a visible color change in less than about 5 seconds when heated to a transition temperature T2, T2 being a sufficient amount greater than T1 that the thermochromic composition does not change color when the article is heated to T1;
- (b) heating substnatially the entire article to at least T1 but less than T2, the thermochromic composition not changing color;
- and
- (c) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 5 seconds so that only a portion of the thermochromic composition changes color.
1 more element
A method for marking a substrate comprising the steps of:
- (a) placing on the substrate a heat-recoverable, tubular, polymeric article that recovers whe heated to a heat-recovery temperature T1, T1 being at least 100.degree. C., the article having a thermochromic paint comprising a thermochromic composition on at least a portion of its outer surface, the thermochromic composition providing a substantially irreversible visible color change in less than about 1 second when heated to a transition temperature T2, T2 being at least 30.degree. C. greater than T1, the thermochromic composition not changing color when the article is heated to T1;
- (b) recovering the article on the substrate without changing the color of the thermochromic composition by heating substantially the entire article to at least T1 but less than T2;
- and
- (c) forming visible indicia on the article by heating only portions of the article to at least T2 for up to about 1 second so that a portion of the thermochromic composition irreversibly changes color.
1 more element
Dependencies are inferred from the claim text.