Coloured labels

Abstract

There is described a coloured, transparent polymeric label which is capable of being fixed to a pre-selected coloured, transparent region of an article (optionally by a wet glue process) to achieve a non-label look on the article, characterised in that: the colour parameters measured in CIE colour space of each of the label, labelled article and un-labelled article together satisfy conditions (a) and/or (b) (a) (i) the modulus of ΔC is less than about 5, more preferably less than about 4, most preferably about 3.5, for example about zero, where: ΔC=C L+A −C A Equation 1 where C L+A =(a L + A 2 +b L + A 2 )½ and C A =(a A 2 +b A 2 )½; and (ii) the modulus of ΔL is less than about 7, preferably less than about 4, most preferably about 3, for example about zero, where: ΔL=L L+A −L A Equation 2; and (iii) the modulus of ΔE is less than about 10, more preferablyless than about 6, most preferably about 4, for example about zero, where: ΔE=(Δa 2 +Δb 2 +ΔL 2 )½ Equation 3; where Δa=a L+A −a L and Δb=b L+A −b L; ; and (iv) the modulus of ΔH is less than about 7, more preferably less than about 5.5, most preferably less than about 2.5, for example about zero, where: ΔH=(ΔE 2 +ΔL 2 +ΔC 2 )½ Equation 4 and/or (b) the modulus of transmitted colour ratio (R trans ) is greater than 0.9 preferably is substantially about 1.0, where R trans =2(E L+A )/(E L +E A ) Equation 5 This provides a method for colour matching a label to a specific article such as a bottle to be labelled to provide a nolabel appearance on the article.

1 . A coloured, transparent polymeric label which is capable of being fixed to a pre-selected coloured transparent region of an article (optionally by a wet glue process) to achieve a non-label look on the article, wherein: the colour parameters measured in CIE colour space of each of the label, labelled article and un-labelled article together satisfy conditions (a) and/or (b): 
 (a) (i) the modulus of ΔC is less than about 5, where:     Δ C=C   L+A   −C   A    Equation 1    where C L+A =(a L+A   2 +b L+A   2 ) 1/2  and C A =(a A   2 +b A   2 ) 1/2 ; and    (ii) the modulus of ΔL is less than about 7, where:       ΔL=L   L+A   −L   A    Equation 2; and    (iii) the modulus of ΔE is less than about 10, where:       ΔE =( Δa   2   +Δb   2   +ΔL   2 ) 1/2    Equation 3;    where Δa=a L+A −a L  and Δb=b L+A −b L; ; and    (iv) the modulus of ΔH is less than about 7, where:     Δ H =(Δ E   2   +ΔL   2   +ΔC   2 ) 1/2    Equation 4    and/or    (b) the modulus of transmitted colour ratio (R trans ) is greater than 0.9 preferably is substantially about 1.0, where                    R   trans     =       2   ⁢     (     E     L   +   A       )         (       E   L     +     E   A       )               Equation   ⁢           ⁢   5                 
     
     
         2 . A label as claimed in  claim 1 , in which the label comprises a polymer film made from cellulose, a cellulose derivative, a polyolefin and/or polylactic acid.  
     
     
         3 . A label as claimed in  claim 1 , in which the label comprises cellulose film or BOPP film.  
     
     
         4 . A method of preparing a coloured, transparent label that can be fixed by a wet glue on to a coloured transparent article and/or region thereof to achieve a no-label appearance thereon the method comprising the steps of 
 (a) measuring the L a b values of the article or region thereof    (b) using Equations 1 to 5 of  claim 1  and the parameter limits given herein to calculating corresponding L a b values required of a label.    (c) colouring a polymeric transparent label to have the L a b values calculated from step (b) where optionally the colouring method is selected from at least one of: 
 (i) colouring the label directly by incorporating dyes or pigments therein;  
 (ii) applying transparent coloured compositions to either or both label surfaces;  
 (iii) printing the surface of the label with pigmented or transparent inks; and/or  
 (iv) colouring a clear wet glue formulation to produce coloured transparent adhesive layer when the glue is applied to the label: and/or  
 (v) any combinations thereof which achieve the desired total colour space values  
   
     
     
         5 . A method for preparing and/or applying a label to a coloured, transparent article and/or region thereof, the method comprising the steps of: 
 (a) coating a label as claimed in  claim 1  on at least one surface thereof with an aqueous composition with an adhesive dispersed therein;    (b) treating at least the opposite surface of the sheet, optionally both surfaces, to improve its printability,    (c) drying the film to remove excess water;    (d) applying the label to an article; and (e) optionally drying the article to affix the label thereon.    
     
     
         6 . A method of labelling a coloured, transparent article and/or region thereof, thereof with a wet glue label to achieve a no-label appearance thereon, the method comprising the steps of 
 (a) measuring the L a b of the article or region thereof    (b) using Equations 1 to 5 of  claim 1  and the parameter limits given herein to calculating corresponding L a b values required of a label.    (c) colouring a polymeric transparent label to have the L*a*b values calculated from step (b), where optionally the colouring method is selected from at least one of: 
 (i) colouring the label directly by incorporating dyes or pigments therein;  
 (ii) applying transparent coloured compositions to either or both label surfaces;  
 (iii) printing the surface of the label with pigmented inks; and/or  
   (iv) colouring a clear wet glue formulation to produce coloured, transparent adhesive layer when the glue is applied to the label: and/or 
 (v) any combinations thereof which achieve the desired total colour space values  
   (d) applying the coloured label prepared in step (c) to the measured region of the article using a wet glue to achieve thereon a labelled article having a no-label appearance.    
     
     
         7 . A label obtained or obtainable by a method as described in  claim 4 .  
     
     
         8 . A label facestock comprising a label as claimed in  claim 1  or  claim 7  adjacent a release liner.  
     
     
         9 . A labelled article where label has a no-label appearance thereon and where the article is obtained or obtainable by a method as described in  claim 5  or  6 , fixed thereto with an aqueous adhesive composition.  
     
     
         10 . An article as claimed in  claim 9 , which comprises a coloured, transparent glass or PET container.  
     
     
         11 . A labelled article where label has a no-label appearance thereon and where the article comprises a label as claimed in  claim 1  or  7  fixed thereto with an aqueous adhesive composition.  
     
     
         12 . An article as claimed in  claim 11  which comprises a coloured, transparent glass or PET container.