Smoking article incorporating a conductive substrate

Abstract

The present invention provides a conductive substrate useful for Joule heating, such as in an electronic smoking article. Particularly, the invention provides a resistive heating element formed of a conductive substrate. The conductive substrate comprises an electrically conductive material and a carbonaceous additive, such as a binder material. The conductive substrate is carbonized in that it is subjected to calcining conditions to effectively reduce the carbonaceous additive to its carbon skeleton. It has been found that such carbonized substrate has surprisingly improved resistance properties in relation a substrate of the same formulation that is not carbonized. The carbonized substrate can include an aerosol precursor material. The formed resistive heating element can be included in an electronic smoking article to simultaneously provide resistive heating and aerosol formation with a single, unitary component.

1 . An aerosol delivery article, comprising:
 a reservoir containing a liquid aerosol precursor composition, the liquid aerosol precursor composition comprising nicotine, at least one polyhydric alcohol, and lactic acid, wherein the lactic acid is present in an amount of 0.1 moles or more of lactic acid per one mole of nicotine;   a heating element positioned proximal to at least a portion of the liquid aerosol precursor composition such that heat form the heating element volatilizes the liquid aerosol precursor composition to form an inhalable aerosol;   a mouthpiece having an opening for delivery of the inhalable aerosol to a user; and   an air flow path for passage of the inhalable aerosol to the mouthpiece.   
     
     
         2 . The aerosol delivery article of  claim 1 , wherein the lactic acid is present in an amount of 0.1 moles to 0.5 moles of lactic acid per mole of nicotine. 
     
     
         3 . The aerosol delivery article of  claim 1 , wherein the lactic acid is present in an amount up to equimolar to the total moles of nicotine. 
     
     
         4 . The aerosol delivery article of  claim 1 , wherein the at least one polyhydric alcohol is present in an amount of 50% to 98% by weight of the liquid aerosol precursor composition. 
     
     
         5 . The aerosol delivery article of  claim 1 , wherein the at least one polyhydric alcohol comprises a first polyol in an amount of about 50% to about 90% by weight of the liquid aerosol precursor composition and a second polyol in an amount of about 2% to about 45% by weight of the liquid aerosol precursor composition. 
     
     
         6 . The aerosol delivery article of  claim 5 , wherein the first polyol is glycerol and the second polyol is propylene glycol. 
     
     
         7 . The aerosol delivery article of  claim 1 , wherein the at least one polyhydric alcohol comprises glycerol and propylene glycol. 
     
     
         8 . The aerosol delivery article of  claim 1 , wherein the liquid aerosol precursor composition further comprises water in an amount of about 2% to about 20% by weight. 
     
     
         9 . The aerosol delivery article of  claim 1 , wherein the nicotine is present in amount of about 0.1 to about 5% by weight of the liquid aerosol precursor composition. 
     
     
         10 . The aerosol delivery article of  claim 9 , further comprising one or more additional flavoring agents in an amount of 0.1% to about 10% by weight of the liquid aerosol precursor composition. 
     
     
         11 . The aerosol delivery article of  claim 1 , wherein the total amount of nicotine, lactic acid, and any additional flavoring agent present in the liquid aerosol precursor composition is about 0.1% to about 10% by weight of the liquid aerosol precursor composition. 
     
     
         12 . The aerosol delivery article of  claim 1 , further comprising at least one additional organic acid present in an amount of 0.1 moles or more per one mole of nicotine. 
     
     
         13 . The aerosol delivery article of  claim 1 , wherein the at least one additional organic acid is levulinic acid. 
     
     
         14 . The aerosol delivery article of  claim 1 , wherein the aerosol delivery article is adapted to deliver the inhalable aerosol in a series of puffs, wherein each puff delivers at least 1.5 mg of wet total particulate matter when smoked under standard FTC smoking conditions of 2 second, 35 ml puffs. 
     
     
         15 . The aerosol delivery article of  claim 1 , further comprising a battery electrically connected to the heating element and a control component adapted to control power delivery from the battery to the heating element. 
     
     
         16 . The aerosol delivery article of  claim 1 , comprising a first unit that is engageable and disengageable with a second unit, wherein the first unit comprises the heating element, the mouthpiece, and the reservoir containing the liquid aerosol precursor composition, and the second unit comprising an electrical power source. 
     
     
         17 . An aerosol delivery article, comprising:
 a reservoir containing a liquid aerosol precursor composition, the liquid aerosol precursor composition comprising nicotine in an amount of about 0.1% to about 5% by weight of the liquid aerosol precursor composition, one or more polyhydric alcohols present in an amount of 50% to 98% by weight of the liquid aerosol precursor composition, and lactic acid, wherein the lactic acid is present in an amount of 0.5 moles or more of lactic acid per one mole of nicotine;   a heating element positioned proximal to at least a portion of the liquid aerosol precursor composition such that heat form the heating element volatilizes the liquid aerosol precursor composition to form an inhalable aerosol;   a mouthpiece having an opening for delivery of the inhalable aerosol to a user; and   an air flow path for passage of the inhalable aerosol to the mouthpiece.   
     
     
         18 . The aerosol delivery article of  claim 17 , further comprising at least one additional organic acid present in an amount of 0.1 moles or more per one mole of nicotine. 
     
     
         19 . The aerosol delivery article of  claim 17 , wherein the at least one additional organic acid is levulinic acid. 
     
     
         20 . An aerosol delivery article, comprising:
 a reservoir containing a liquid aerosol precursor composition, the liquid aerosol precursor composition comprising nicotine in an amount of about 0.1% to about 5% by weight of the liquid aerosol precursor composition, a combination of glycerol and propylene glycol present in an amount of 50% to 98% by weight of the liquid aerosol precursor composition, lactic acid, wherein the lactic acid is present in an amount of 0.1 moles or more of lactic acid per one mole of nicotine, and at least one additional organic acid present in an amount of 0.1 moles or more of the at least one additional organic acid per one mole of nicotine;   a heating element positioned proximal to at least a portion of the liquid aerosol precursor composition such that heat form the heating element volatilizes the liquid aerosol precursor composition to form an inhalable aerosol;   a mouthpiece having an opening for delivery of the inhalable aerosol to a user; and   an air flow path for passage of the inhalable aerosol to the mouthpiece.   
     
     
         21 . The aerosol delivery article of  claim 20 , wherein glycerol is present in an amount of about 50% to about 90% by weight of the liquid aerosol precursor composition and propylene glycol is present in an amount of about 2% to about 45% by weight of the liquid aerosol precursor composition, and wherein the liquid aerosol precursor composition further comprises water in an amount of about 2% to about 20% by weight.