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: 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 composition 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 the group consisting of an alkyl (meth)acrylate esters of an alcohol wherein the alkyl portion of the alcohol has 1 to 2 carbon atoms, N-vinyl-2-pyrrolidone, and mixtures thereof; and    (d) an effective amount of a crosslinker selected from the group consisting of diallyl maleate and compounds represented by the formula:                          wherein R is selected from the group consisting of hydrogen, methyl, and ethyl, and R′ is selected from the group consisting of vinyl (—HC═CH 2 ), allyl (—CH 2 —CH═CH 2 ), and methallyl (—C(—CH 2 )═CH 2 );    wherein said pressure sensitive adhesive does not contain a plasticizer,    and wherein said removable, plasticizer resistant pressure sensitive adhesive has an initial peel strength of less than about 0.3 pounds per inch peel force.    
   
   
       2 - 18 . (canceled)  
   
   
       19 . A removable, plasticizer resistant pressure sensitive adhesive composition 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 the group consisting of an alkyl (meth)acrylate esters of an alcohol wherein the alkyl portion of the alcohol has 1 to 2 carbon atoms, N-vinyl-2-pyrrolidone, and mixtures thereof; and    (d) an effective amount of a crosslinker selected from the group consisting of diallyl maleate and compounds represented by the formula:                          wherein R is selected from the group consisting of hydrogen, methyl, and ethyl, and R′ is selected from the group consisting of vinyl (—HC═CH 2 ), allyl (—CH 2 —CH═CH 2 ), and methallyl (—C(—CH 2 )═CH 2 );    wherein said pressure sensitive adhesive does not contain a plasticizer,    and wherein said removable, plasticizer resistant pressure sensitive adhesive has an initial peel strength of less than about 0.3 pounds per inch peel force;    and wherein the amount of said crosslinker is from about 0.2 to about 1.0 wt. %.    
   
   
       20 . The composition of  claim 19  wherein said crosslinker is selected from the group consisting of allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, methallyl acrylate, methallyl methacrylate, and mixtures thereof.  
   
   
       21 - 22 . (canceled)  
   
   
       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,    and wherein said removable, plasticizer resistant pressure sensitive adhesive has an initial peel strength of less than about 0.3 pounds per inch peel force.    
   
   
       24 . A label prepared from a removable, plasticizer resistant pressure sensitive adhesive of  claim 1 .  
   
   
       25 . A tape prepared from a removable, plasticizer resistant pressure sensitive adhesive of  claim 1 .  
   
   
       26 . A film prepared from a removable, plasticizer resistant pressure sensitive adhesive of  claim 1.