Lid for a Container and a Process for Making the Same

Abstract

A lid ( 2 ) for a container ( 67 ), the lid ( 2 ) comprising a first plastic layer ( 15 ) including a portion having at least one colored pigment and a second plastic layer ( 14 ) including at least one thermochromic substance capable of becoming translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container so as to reveal the colored pigment of the first layer. Alternatively, there is described a lid comprising a layer with a portion ( 62,63 ) that becomes either observable or non-observable at the predetermined temperature.

1 . A lid for a container, the lid comprising a first plastic layer and a second plastic layer disposed on top of the first layer, the first layer including at least one portion comprising at least one coloured pigment, the second layer including at least one portion comprising at least one thermochromic substance which is capable of becoming substantially translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container so as to reveal at least one of the portions comprising the coloured pigment of the first layer. 
   
   
       2 . A lid for a container, the lid comprising a first HIPS layer and a second HIPS layer disposed on top of the first layer, the first layer comprising at least one portion having at least one coloured pigment, the second layer including at least one portion having at least one thermochromic substance in an amount up to 12 wt % of the layer and having a reduced particle size, which thermochromic substance is capable of becoming substantially translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container so as to reveal at least one of the portions comprising the coloured pigment of the first layer, the second layer having a thickness substantially less than the thickness of the first layer. 
   
   
       3 . A lid according to  claim 1  including one or more additional plastic layer(s). 
   
   
       4 . A lid according to  claim 3  wherein the additional plastic layer(s) include one or more of coloured pigment(s), thermochromic substance(s) or regrind. 
   
   
       5 . A lid according to  claim 1  for a hot or cold cup or container. 
   
   
       6 . A lid according to  claim 1  wherein each layer of the lid ranges from about 100 μm up to about 400 μm thickness, with the total thickness of the lid for a two layer lid in the range of 200 μm to about 800 μm. 
   
   
       7 . A lid according to  claim 1  wherein the second layer is an upper layer of the lid and the first layer is a lower layer of the lid and additional plastic layers are positioned below the first layer. 
   
   
       8 . A lid according to  claim 1  wherein the second layer is an upper layer of the lid and the first layer is a lower layer of the lid and an additional plastic layer(s) includes a thermochromic material and is positioned above the second layer. 
   
   
       9 . A lid according to  claim 7  wherein the upper layer of the lid is about 15% to about 50% of the total lid thickness. 
   
   
       10 . A lid according to  claim 1  wherein the portion of thermochromic substance and coloured pigment in each layer is substantially all of the lid or one or more smaller portion(s) of the lid provided that at least one of the portions of the second layer must sufficiently cover a portion of the first layer so as to reveal that portion at the predetermined temperature. 
   
   
       11 . A lid according to  claim 1  wherein the first layer includes regrind of the lid or regrind of a different lid. 
   
   
       12 . A lid according to  claim 1  wherein the thermochromic substance has a reduced particle size and is selected from the group consisting of Matsui Chromicolor BW Grade or PS Conc. 
   
   
       13 . A lid according to  claim 1  wherein the coloured pigment of the first layer is such that the first layer is opaque at both the predetermined temperature and a temperature other than the predetermined temperature. 
   
   
       14 . A lid according to  claim 1  wherein the coloured pigment is a standard pigment dye other than a white pigment or is a standard pigment dye combined with a white pigment. 
   
   
       15 . A lid according to  claim 1  wherein the coloured pigment is added in an add-on rate of about 1 to about 4 wt %. 
   
   
       16 . A lid according to  claim 1  wherein the thermochromic substance is included in an amount of about 6 wt % to about 10 wt %. 
   
   
       17 . A lid according to  claim 1 , wherein the colour of the thermochromic substance and the coloured pigment in each layer is selected so that a colour or combination of colours which results is an observable colour at the temperature other than the predetermined temperature and which colour is distinguishable from the colour of the lid at the predetermined temperature. 
   
   
       18 . A lid according to  claim 1 , wherein the portion which is revealed forms a word, symbol, logo, picture or pattern. 
   
   
       19 . A lid according to  claim 1 , wherein the colour change of the thermochromic substance is reversible, quasi-reversible or non-reversible. 
   
   
       20 . A lid according to  claim 1 , wherein there is more than one predetermined temperature. 
   
   
       21 . A lid according to  claim 1 , wherein the predetermined temperature is a predetermined non-ambient temperature selected from a predetermined heated non-ambient temperature above about 25° C. or a predetermined cooled non-ambient temperature below about 25° C. 
   
   
       22 . A lid for a container according to  claim 1 , wherein the lid is a coffee cup lid and the thermochromic substance is capable of becoming substantially translucent upon reaching a predetermined temperature in response to heat transfer from the contents of the container. 
   
   
       23 . A lid for a container, the lid comprising a layer comprising at least one portion having at least one thermochromic substance which is adapted to change colour and/or become substantially translucent upon reaching a predetermined temperature(s) in response to heat transfer from or to contents of the container, the layer being provided in at least one portion with at least one coloured pigment, which portion is observable at said predetermined temperature(s) and non-observable at a temperature other than the predetermined temperature(s), the colour of said pigment being the same or substantially the same colour as that of said thermochromic substance at a temperature other than the predetermined temperature(s) or which portion becomes non-observable at said predetermined temperature(s) and observable at a temperature other than the predetermined temperature(s), the colour of said pigment being the same or substantially the same colour as that of said thermochromic substance at the predetermined temperature(s). 
   
   
       24 . A lid according to  claim 23  wherein the observable portion forms a word, symbol, a logo, pattern or picture. 
   
   
       25 . (canceled) 
   
   
       26 . A process for preparing a lid for a container comprising:
 co-extruding a first plastic layer and a second plastic layer, and optionally one or more additional plastic layers, the first layer comprising in at least one portion at least one coloured pigment, the second layer comprising at least one portion comprising at least one thermochromic substance which is adapted to become substantially translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container to reveal at least one of the portions having the coloured pigment of the first layer.   
   
   
       27 . A lid according to  claim 1  wherein regrind is added to one or more layers of the lid. 
   
   
       28 . A lid for a container, the lid comprising a first plastic layer and a second plastic layer disposed on top of the first layer and optionally one or more additional plastic layers, the first layer including at least one portion comprising at least one coloured pigment, the second layer including at least one portion comprising at least one thermochromic substance which is capable of becoming substantially translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container so as to reveal at least one of the portions comprising the coloured pigment of the first layer, wherein one or more of the layers of the lid include regrind.