High temperature thermal cutoff device

Abstract

The present disclosure provides high temperature thermal cutoff devices having a high-temperature thermal pellet with a transition temperature of greater than or equal to about 240° C. and comprising at least one organic compound. The pellet is disposed in a housing, which is sealed with a high-temperature seal that provides substantial sealing up to at least the transition temperature. The high-temperature TCO also has a current interruption assembly, which establishes electrical continuity in a first operating condition corresponding to an operating temperature of less than said transition temperature and discontinues electrical continuity when the operating temperature exceeds the transition temperature. Methods of making such high-temperature thermal cut off devices are also provided.

1 . A high temperature thermal cutoff device comprising:
 a high-temperature thermal pellet having a transition temperature of greater than or equal to about 240° C. comprising at least one organic compound disposed in a housing;   a high-temperature seal disposed in a portion of at least one opening of said housing to substantially seal said housing up to said transition temperature; and   a current interruption assembly at least partially disposed within said housing that establishes electrical continuity in a first operating condition corresponding to an operating temperature of less than said transition temperature of said pellet, and that discontinues electrical continuity when said operating temperature exceeds said transition temperature.   
   
   
       2 . The high temperature thermal cutoff device of  claim 1 , wherein said at least one organic compound organic compounds has a melting point temperature (mp) of T−5° C.≦mp≦T+2° C., where T represents said transition temperature of said high-temperature thermal pellet. 
   
   
       3 . The high temperature thermal cutoff device of  claim 1 , wherein said at least one organic compound comprises a polycyclic organic compound. 
   
   
       4 . The high temperature thermal cutoff device of  claim 1 , wherein said at least one organic compound comprises triptycene. 
   
   
       5 . The high temperature thermal cutoff device of  claim 1 , wherein said at least one organic compound comprises 1-aminoanthroquinone. 
   
   
       6 . The high temperature thermal cutoff device of  claim 1 , wherein said pellet comprises greater than or equal to about 95 weight % of said at least one organic compound. 
   
   
       7 . The high temperature thermal cutoff device of  claim 1 , wherein said pellet comprises one or more components selected from the group consisting of: a binder, a press aid, a release agent, a pigment, or mixtures thereof. 
   
   
       8 . The high temperature thermal cutoff device of  claim 1 , wherein said high temperature seal comprises an epoxy-based sealant formed from precursors comprising a diglycidyl ether bisphenol A resin and a hardener. 
   
   
       9 . The high temperature thermal cutoff device of  claim 8 , wherein said hardener comprises a modified imidazole compound. 
   
   
       10 . The high temperature thermal cutoff device of  claim 8 , wherein said hardener comprises a 2-ethyl-4-methyl-1H-imidazole. 
   
   
       11 . The high temperature thermal cutoff device of  claim 8 , wherein said epoxy-based sealant is formed by combining at least two epoxy precursors, wherein a first precursor comprises at least one bisphenol A diglycidyl ether, an elastomer, and neopentyl glycol diglycidyl ether; and a second precursor comprises 2-ethyl-4-methyl-1H-imidazole. 
   
   
       12 . The high temperature thermal cutoff device of  claim 8 , wherein said epoxy-based sealant is formed by combining at least two epoxy precursors, wherein a first precursor comprises a bisphenol A diglycidyl ether polymer; a second precursor comprises a 1-(2-cyanoethyl)-2-ethyl-4-methyl imidizole; and a third precursor comprises benzenetetracarboxylic-1,2,4,5-dianhydride, hexahydrophthalic anhydride, and phthalic anhydride. 
   
   
       13 . The high temperature thermal cutoff device of  claim 1 , wherein said transition temperature is greater than or equal to about 240° C. and less than or equal to about 270° C. 
   
   
       14 . The high temperature thermal cutoff device of  claim 1 , wherein said device is capable of operating at greater than or equal to about 1,000 hours at a sustained temperature of about 235° C. 
   
   
       15 . A high temperature thermal cutoff device comprising:
 a housing having at least one opening;   a high-temperature thermal pellet having a transition temperature of greater than or equal to about 240° C. comprising at least one crystalline organic compound and disposed in said housing;   a high-temperature seal disposed in a portion of said opening to substantially seal said housing to said transition temperature of said high-temperature thermal pellet;   a current interruption assembly comprising: an electric contact in electrical continuity with an external current source to establish an electrical circuit in a first operating condition corresponding to an operating temperature of less than said transition temperature of said pellet, wherein at least a portion of said electric contact is disposed within said housing, a sliding contact member disposed within said housing, and a tensioning mechanism disposed in said housing to bias said sliding contact member against said electric contact in said first operating condition to maintain an electrical circuit and to release and interrupt electrical continuity between said sliding contact member and said electric contact in a second operating condition when said operating temperature is greater than said transition temperature.   
   
   
       16 . The high temperature thermal cutoff device of  claim 15 , wherein said at least one crystalline organic compound comprises a polycyclic organic compound. 
   
   
       17 . The high temperature thermal cutoff device of  claim 15 , wherein said at least one crystalline organic compound comprises triptycene. 
   
   
       18 . The high temperature thermal cutoff device of  claim 15 , wherein said at least one crystalline organic compound comprises 1-aminoanthroquinone. 
   
   
       19 . The high temperature thermal cutoff device of  claim 15 , wherein said pellet comprises greater than or equal to about 95 weight % of said at least one crystalline organic compound. 
   
   
       20 . The high temperature thermal cutoff device of  claim 15 , wherein said pellet comprises one or more components selected from the group consisting of: a binder, a press aid, a release agent, a pigment, or mixtures thereof. 
   
   
       21 . The high temperature thermal cutoff device of  claim 15 , wherein said high temperature seal comprises an epoxy-based sealant formed from precursors comprising a diglycidyl ether bisphenol A resin and a hardener. 
   
   
       22 . The high temperature thermal cutoff device of  claim 21 , wherein said hardener comprises a modified imidazole compound. 
   
   
       23 . The high temperature thermal cutoff device of  claim 22 , wherein said hardener comprises a 2-ethyl-4-methyl-1H-imidazole. 
   
   
       24 . The high temperature thermal cutoff device of  claim 21 , wherein said epoxy-based sealant is formed by combining at least two epoxy precursors, wherein a first precursor comprises at least one bisphenol A diglycidyl ether, an elastomer, and neopentyl glycol diglycidyl ether; and a second precursor comprises 2-ethyl-4-methyl-1H-imidazole. 
   
   
       25 . The high temperature thermal cutoff device of  claim 21 , wherein said epoxy-based sealant is formed by combining at least two epoxy precursors, wherein a first precursor comprises a bisphenol A diglycidyl ether polymer; a second precursor comprises a 1-(2-cyanoethyl)-2-ethyl-4-methyl imidizole; and a third precursor comprises benzenetetracarboxylic-1,2,4,5-dianhydride, hexahydrophthalic anhydride, and phthalic anhydride. 
   
   
       26 . The high temperature thermal cutoff device of  claim 15 , wherein said transition temperature is greater than or equal to about 240° C. and less than or equal to about 270° C. 
   
   
       27 . The high temperature thermal cutoff device of  claim 15 , wherein the device is capable of operating at greater than or equal to about 1,000 hours at a sustained temperature of about 235° C. 
   
   
       28 . A high temperature thermal cutoff device comprising:
 a housing containing a high-temperature thermal pellet having a transition temperature of greater than or equal to about 240° C. and comprising at least one crystalline organic compound selected from the group consisting of: triptycene and 1-aminoanthroquinone;   a high-temperature epoxy-based seal disposed in a portion of at least one opening of said housing to substantially seal said housing up to said transition temperature; and   a current interruption assembly at least partially disposed within said housing that establishes electrical continuity in a first operating condition corresponding to an operating temperature of less than said transition temperature of said pellet, and that discontinues electrical continuity when said operating temperature exceeds said transition temperature, wherein the high-temperature thermal cut-off device is capable of operating at greater than or equal to about 1,000 hours at a sustained temperature of about 235° C.   
   
   
       29 . A method of making a high temperature thermal cutoff device comprising:
 disposing a high-temperature thermal pellet in a thermal cutoff device housing, wherein said high-temperature thermal pellet has a transition temperature of greater than or equal to about 240° C. and comprises at least one crystalline organic compound;   disposing a current interruption assembly at least partially in said housing, wherein said current interruption assembly is capable of establishing electrical continuity in a first operating condition corresponding to an operating temperature of less than said transition temperature of said thermal pellet, and discontinuing electrical continuity when said operating temperature exceeds said transition temperature;   sealing at least one opening in the housing with a high-temperature epoxy-based seal to form a sealed housing, wherein the high-temperature thermal cut-off device is capable of operating at greater than or equal to about 1,000 hours at a sustained temperature of about 235° C.   
   
   
       30 . The method of  claim 29 , wherein said sealing further comprises applying a curable epoxy-based mixture over said at least one opening and curing said curable epoxy-based mixture to form a high-temperature seal.