Removable pressure sensitive adhesives with plasticizer resistance properties

Abstract

A removable, plasticizer resistant pressure sensitive composition that is particularly useful for PSA applications on plasticizer containing vinyl films is provided. The pressure sensitive adhesive comprises: (a) at least one hydrophobic monomer, (b) about 0.2 to about 10 wt. % of at least one hydrophilic monomer; (c) about 1 to about 40 wt. % of one partially hydrophilic monomer (d) an effective amount of a crosslinker selected from diallyl maleate or a compound represented by the formula (I): (I), wherein R is selected from hydrogen, methyl, or ethyl, and R′ is selected from vinyl, allyl, or methallyl; wherein the pressure sensitive adhesive does not contain a plasticizer.

1 . A removable, plasticizer resistant pressure sensitive adhesive comprising a crosslinked aqueous emulsion polymer comprising: 
 (a) at least one hydrophobic monomer selected from an alkyl (meth)acrylate ester of an alcohol wherein the alkyl portion of the alcohol is linear or branched and contains at least 4 carbon atoms;    (b) about 0.2 to about 10 wt. % of at least one hydrophilic monomer; and    (c) about 1 to about 40 wt. % of one partially hydrophilic monomer selected from alkyl (meth)acrylate esters of an alcohol wherein the alkyl portion of the alcohol has 1 to 2 carbon atoms, N-vinyl-2-pyrrolidone, or mixtures thereof; and    (d) an effective amount of a crosslinker selected from diallyl maleate or compounds represented by the formula:                        wherein R is selected from hydrogen, methyl, or ethyl, and R′ is selected from vinyl (—HC═CH 2 ), allyl (—CH 2 —CH═CH 2 ), or methallyl (—C(—CH 2 )═CH 2 );      wherein said pressure sensitive adhesive does not contain a plasticizer.    
   
   
       2 . The composition of  claim 1  wherein said removable, plasticizer resistant pressure sensitive adhesive has an initial peel strength of less than about 0.3 pounds per inch peel force with adhesive failure mode.  
   
   
       3 . The composition of  claim 1  wherein the amount of monomer (a) in said crosslinked aqueous emulsion polymer is about 50 to about 90 wt. %.  
   
   
       4 . The composition of  claim 1  wherein the amount of monomer (a) in said crosslinked aqueous emulsion polymer is about 60 to about 84 wt. %.  
   
   
       5 . The composition of  claim 4  wherein the amount of monomer (a) in said crosslinked aqueous emulsion polymer is about 70 to about 80 wt. %.  
   
   
       6 . The composition of  claim 1  wherein the amount of monomer (b) in said crosslinked aqueous emulsion polymer is about 0.2 to about 5 wt. %.  
   
   
       7 . The composition of  claim 6  wherein the amount of monomer (b) in said crosslinked aqueous emulsion polymer is about 1 to about 3 wt. %.  
   
   
       8 . The composition of  claim 1  wherein the amount of monomer (c) in said crosslinked aqueous emulsion polymer is about 10 to about 25 wt. %.  
   
   
       9 . The composition of  claim 8  wherein the amount of monomer (c) in said crosslinked aqueous emulsion polymer is about 12 to about 25 wt. %.  
   
   
       10 . The composition of  claim 1  wherein said monomer (a) is selected from isooctyl acrylate, 4-methyl-2-pentyl acrylate, 2-methylbutyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isodecyl methacrylate, isononyl acrylate, isodecyl acrylate, or mixtures thereof.  
   
   
       11 . The composition of  claim 10  wherein said monomer (a) is 2-ethyl-hexyl acrylate, n-butyl acrylate, and mixtures thereof.  
   
   
       12 . The composition of  claim 1  wherein said monomer (b) is selected from a monoolefinic monocarboxylic acid, a monoolefinic dicarboxylic acid, 2-hydroxyethyl acrylate, or mixtures thereof.  
   
   
       13 . The composition of  claim 12  wherein said monomer (b) is selected from acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, oligomeric acrylic acid, 2-hydroxyethyl acrylate, or mixtures thereof.  
   
   
       14 . The composition of  claim 13  wherein said monomer (b) is acrylic acid, 2-hydroxyethyl acrylate, methacrylic acid, or mixtures thereof.  
   
   
       15 . The composition of  claim 1  wherein said monomer (c) is selected from methyl acrylate, methyl methacrylate, ethyl acrylate, N-vinyl-2-pyrrolidone or mixtures thereof.  
   
   
       16 . The composition of  claim 15  wherein said monomer (c) is ethyl acrylate.  
   
   
       17 . The composition of  claim 1  wherein the amount of said crosslinker is from about 0.2 to about 1.0 wt. %.  
   
   
       18 . The composition of  claim 17  wherein the amount of said crosslinker is from about 0.3 to about 0.6 wt. %.  
   
   
       19 . The composition of  claim 17  wherein said crosslinker is represented by the formula:  
     
       
         
         
             
             
         
       
       wherein R is selected from hydrogen, methyl, or ethyl, and R′ is selected from vinyl (—HC═CH 2 ), allyl (—CH 2 —CH═CH 2 ), or methallyl (—C(—CH 2 )═CH 2 ).  
     
   
   
       20 . The composition of  claim 19  wherein said crosslinker is selected from allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, methallyl acrylate, methallyl methacrylate, or mixtures thereof.  
   
   
       21 . The composition of  claim 20  wherein said crosslinker is allyl acrylate or allyl methacrylate.  
   
   
       22 . The composition of  claim 17  wherein said crosslinker is diallyl maleate.  
   
   
       23 . A removable, plasticizer resistant pressure sensitive adhesive comprising a crosslinked aqueous emulsion polymer comprising: 
 (a) from about 70 to about 80 wt. % amount of 2-ethylhexyl acrylate, n-butyl acrylate, or mixtures thereof;    (b) from about 1 to about 3 wt. % of acrylic acid, 2-hydroxyethyl acrylate, methacrylic acid, or mixtures thereof;    (c) from about 12 to about 25 wt. % of ethyl acrylate; and    (d) from about 0.3% to about 0.6 wt. % of diallyl maleate, allyl methacrylate, allyl acrylate or mixtures thereof;    wherein said pressure sensitive adhesive does not contain a plasticizer    
   
   
       24 - 26 . (canceled)