Surface treatment of beverage containers to keep the beverage cool

Abstract

The invention pertains to a method suitable to reduce the heat transfer into a beverage container in order to keep the beverage cool over an extended period of time after taken from the refrigerator. The method is based on a surface treatment of the beverage container which comprises a binder in which phase change material is incorporated. By absorbing latent heat without a temperature increase, the phase change material creates a thermal barrier against heat penetration. The binder with the phase change material contained wherein is applied to the surface of the beverage container, for instance, by spray coating. The coating layer covers most of the container's surface. A second coating layer which does not contain phase change material is applied on top of the first coating layer in order to provide protection against mechanical stress during high speed filling and packaging.

1 . A method to keep a beverage cool over an extended period after the beverage container is taken from the refrigerator realized by a surface treatment of the container comprising: a first layer made of a polymeric compound which contains non-microencapsulated phase change material cross-linked wherein applied to the surface of the container by a coating technique in a first step, and a second layer made of a polymeric compound which does not contain phase change material and which is topically applied to the first layer as a protective coating by a coating technique in a second step, and where the phase change material is used to limit the heat transfer into the beverage container by absorbing latent heat generated from an external heat source such as the consumer's hand and where a visible change in the appearance of the container's surface from icy-white during refrigeration to transparent during room temperature conditions occurs due to the change in the appearance of the phase change material from opaque to transparent during the latent heat absorption. 
     
     
         2 . The method according to  claim 1 , where the phase change material used to reduce the heat transfer into the beverage container is a mixture of crystalline alkyl hydrocarbons which absorbs latent heat in a temperature range between 5° C. and 15° C. 
     
     
         3 . The method according to  claim 1 , where the phase change material mixture used to reduce the heat transfer into the beverage container consists of about 10 wt. % to 15 wt. % Tetradecane and 85 wt. % to 90 wt. % Hexadecane. 
     
     
         4 . The method according to  claim 1 , where the phase change material mixture used to reduces the heat transfer into the beverage container possesses a latent heat storage capacity of about 200 J/g. 
     
     
         5 . The method according to  claim 1 , where the phase change material mixture used to reduce the heat transfer into the beverage container is integrated in a polymeric compound in a quantity of up to 60 wt. %. 
     
     
         6 . The method according to  claim 1 , where the phase change material mixture used to reduce the heat transfer into the beverage container is integrated into a polymeric compound which is applied to the surface of the beverage container by spray coating, or dip-coating, or belt or roller coating, or screen printing in a first step. 
     
     
         7 . The method according to  claim 1 , where a protective layer of a polymeric compound which does not contain phase change material which is applied to the surface of the beverage container on top of the first layer by spray coating, or dip-coating, or belt or roller coating in a second step. 
     
     
         8 . The method according to  claim 1 , where the surface treatment covers the main body of the beverage container. 
     
     
         9 . The method according to  claim 1 , where the surface treatment covers the main body and the bottom of the beverage container. 
     
     
         10 . The method according to  claim 1 , where the beverage containers surface appearance changes from icy-white under low refrigerator temperatures to transparent under room temperature conditions.