Water-soluble pressure sensitive adhesives

Abstract

A water-soluble pressure sensitive adhesive comprises a homogeneous blend comprising (a) a polymer selected from the group consisting of N-vinyl caprolactam homopolymers, N-vinyl pyrrolidone copolymers, and mixtures thereof and (b) a non-volatile plasticizer comprising a monohydric or polyhydric alcohol having hydrophilic-lipophilic balance of about 2 to about 10. The N-vinyl pyrrolidone copolymers comprise about 60% or less by weight N-vinyl pyrrolidone.

1 . A pressure sensitive adhesive comprising a homogeneous blend comprising:
 (a) a polymer selected from the group consisting of N-vinyl caprolactam homopolymers, N-vinyl pyrrolidone copolymers, and mixtures thereof, the N-vinylpyrrolidone copolymers comprising about 60% or less by weight N-vinyl pyrrolidone; and   (b) a non-volatile plasticizer comprising a monohydric or polyhydric alcohol having hydrophilic-lipophilic balance of about 2 to about 10;   wherein the pressure sensitive adhesive is water-soluble.   
     
     
         2 . The pressure sensitive adhesive of  claim 1  wherein the polymer comprises from about 35% to about 75% by weight of the pressure sensitive adhesive. 
     
     
         3 . The pressure sensitive adhesive of  claim 1  wherein the plasticizer comprises from about 10% to about 80% by weight of the pressure sensitive adhesive. 
     
     
         4 . The pressure sensitive adhesive of  claim 1  wherein the polymer is an N-vinyl caprolactam homopolymer 
     
     
         5 . The pressure sensitive adhesive of  claim 1  wherein the polymer is an N-vinyl pyrrolidone copolymer. 
     
     
         6 . The pressure sensitive adhesive of  claim 5  wherein the polymer is selected from the group consisting of N-vinyl caprolactam/N-vinyl pyrrolidone copolymers and vinyl acetate/N-vinyl pyrrolidone copolymers, the vinyl acetate/N-vinyl pyrrolidone copolymers comprising from about 20% to about 60% by weight N-vinyl pyrrolidone. 
     
     
         7 . The pressure sensitive adhesive of  claim 6  wherein the polymer is a copolymer of N-vinyl pyrrolidone and vinyl acetate comprising from about 30% to about 50% by weight N-vinyl pyrrolidone. 
     
     
         8 . The pressure sensitive adhesive of  claim 1  wherein the N-vinylpyrrolidone copolymers comprise about 30% or less by weight N-vinyl pyrrolidone. 
     
     
         9 . The pressure sensitive adhesive of  claim 1  wherein the polymer has an overall number average molecular weight from about 10,000 daltons to about 100,000 daltons. 
     
     
         10 . The pressure sensitive adhesive of  claim 1  wherein the polymer further comprises a comonomer in an amount up to about 10% by weight, the comonomer having no carboxylic acid functionality or tetraalkyl ammonium functionality. 
     
     
         11 . The pressure sensitive adhesive of  claim 1  wherein the plasticizer has a vapor pressure below about 0.1 mm Hg at 20° C. 
     
     
         12 . The pressure sensitive adhesive of  claim 1  wherein the plasticizer has a water solubility of less than about 5 g/100 g. 
     
     
         13 . The pressure sensitive adhesive of  claim 1  wherein the plasticizer is selected from the group consisting of polyether glycols having a carbon to oxygen mole ratio greater than about 2.5:1, polyester polyols, C5-C10 alkyl diols, C4-C10 carboxylate monoesters of propylene glycol, C4-C10 carboxylate mono- and diesters of glycerin, C4-C10 alkyl monoethers of propylene glycol, C4-C10 alkyl mono- and diethers of glycerin, C4-C10 alkyl esters of lactic acid, C2-C4 triesters of citric acid, and mixtures thereof. 
     
     
         14 . The pressure sensitive adhesive of  claim 13  wherein the plasticizer is a polyether polyol. 
     
     
         15 . The pressure sensitive adhesive of  claim 14  wherein the plasticizer is a polypropylene glycol. 
     
     
         16 . The pressure sensitive adhesive of  claim 1  wherein the pressure sensitive adhesive increases in weight less than about 15% after two days at 75% relative humidity and 40° C. 
     
     
         17 . The pressure sensitive adhesive of  claim 16  wherein the pressure sensitive adhesive increases in weight less than about 10% after two days at 75% relative humidity and 40° C. 
     
     
         18 . A device for skin contacting applications comprising a flexible backing and the pressure sensitive adhesive of  claim 1  on at least a portion of one side of the flexible backing. 
     
     
         19 . The device of  claim 18  wherein the backing has a moisture vapor transmission rate of at least about 500 g/m 2 /24 hours. 
     
     
         20 . The device of  claim 18  wherein the backing comprises a plurality of opening or holes. 
     
     
         21 . The device of  claim 18  wherein the backing is water-soluble. 
     
     
         22 . The device of  claim 18  further comprising an absorbent pad. 
     
     
         23 . The device of  claim 22  wherein the absorbent pad is water-soluble. 
     
     
         24 . The device of  claim 18  further comprising a support layer releasably adhered to the backing, the pressure sensitive adhesive, or both. 
     
     
         25 . The device of  claim 18  wherein the device is a tape, bandage, wound dressing, or patch. 
     
     
         26 . The device of  claim 18  wherein the device is a patch designed to deliver one or more active agents to a body surface, the patch comprising one or more active ingredients in association with the backing, the pressure sensitive adhesive, or both.