Pressure Sensitive Adhesives Based on Renewable Resources, UV Curing and Related Methods

Abstract

One embodiment is a pressure sensitive adhesive label or tape that comprises a facestock, and a pressure sensitive adhesive composition disposed on the facestock and the pressure sensitive adhesive composition includes a product made from reacting an epoxidized naturally occurring oil or fat with a dimer acid. Another embodiment of the invention is a method that comprises reacting an epoxidized naturally occurring oil or fat with a dimer acid to form a PSA precursor; coating the PSA precursor onto a carrier and curing the PSA precursor via UV radiation to form a pressure sensitive adhesive.

What is claimed is: 
     
         1 . A method comprising:
 reacting an epoxidized naturally occurring oil or fat with one or more reagents selected from a dimer acid, a diacid, and combinations thereof to form a pressure sensitive adhesive precursor.   
     
     
         2 . The method of  claim 1 , wherein the pressure sensitive adhesive precursor is UV cured and a photo catalyst is added to the pressure sensitive adhesive precursor prior to curing. 
     
     
         3 . A method comprising:
 reacting an epoxidized naturally occurring oil or fat with at least one dimer acid and at least one additional component selected from one or more of monoepoxides, monoacids, polyols, biobased polyols, UV enhancers, and catalysts to form the pressure sensitive adhesive precursor.   
     
     
         4 . The method of  claim 3 , wherein the at least one additional component is a biobased polyol including castor oil. 
     
     
         5 . The method of  claim 4  , further comprising:
 curing the pressure sensitive adhesive precursor using thermal cure, radiation cure, or combinations thereof. 
 
     
     
         6 . A method of forming a pressure sensitive adhesive, the method comprising:
 reacting an epoxidized naturally occurring oil or fat with diacid to form a pressure sensitive adhesive precursor;   adding a photo catalyst to pressure sensitive adhesive precursor; and   curing the pressure sensitive adhesive precursor using UV radiation to form a pressure sensitive adhesive.   
     
     
         7 . A method comprising:
 reacting an epoxidized naturally occurring oil or fat with a dimer acid to form a PSA precursor;   coating the PSA precursor onto a carrier;   curing the PSA precursor to form a pressure sensitive adhesive.   
     
     
         8 . A pressure sensitive adhesive label or tape, comprising:
 a face stock,   a layer of pressure sensitive adhesive, at least a portion of which is produced by reacting an epoxidized naturally occurring oil or fat with one or more reagents selected from the group consisting of a dimer and a diacid.   
     
     
         9 . The pressure sensitive adhesive label or tape of  claim 8 , wherein the face stock is a polymeric film, and the polymeric film comprises biobased materials. 
     
     
         10 . The pressure sensitive adhesive label or tape of  claim 8 , wherein the face stock is a paper or film. 
     
     
         11 . A method of forming a pressure sensitive adhesive, the method comprising:
 reacting an epoxidized naturally occurring oil or fat with at least one additional reagent to form a PSA precursor at an elevated temperature for a given time period;   mixing a photoacids generator with the PSA precursor;   applying the PSA precursor onto a carrier;   curing the PSA precursor with radiation to form a pressure sensitive adhesive.   
     
     
         12 . The method of  claim 11 , further comprising
 post curing the product at an elevated temperature for a period of time less than about 2 minutes.   
     
     
         13 . The method of  claim 11 , further comprising
 storing the product at ambient condition before the mixing step.   
     
     
         14 . The method of  claim 12 , wherein the post curing is conducted using hot rollers. 
     
     
         15 . The method of  claim 11 , further comprising adding at least one enhancer selected from one or more of crosslinkers, catalyst, co-initiators, tackifiers, UV absorber, enhancer, and sensitizers. 
     
     
         16 . The method of  claim 15 , wherein the enhancer is selected from one or more of methyltriethoxysilane, tetraethyl orthosilicate, 1,4-cyclohexanedimethanol diglycidyl ether, pentaerythritol, tetra (ethylene glycol dimethyl ether), IRGACURE 819, acetophenone, benzophenone, anthracene and ITX. 
     
     
         17 . The method of  claim 11 , wherein the curing is through thermal cure, radiation cure, or combinations thereof. 
     
     
         18 . A pressure sensitive adhesive label or tape, comprising:
 a facestock; and   a pressure sensitive adhesive composition disposed on the facestock, wherein at least a portion of the pressure sensitive adhesive composition includes a product made from reacting an epoxidized naturally occurring oil or fat with one or more of a dimer acid and a diacid.   
     
     
         19 . The pressure sensitive adhesive label or tape of  claim 18 , comprising: at least two layers of adhesive disposed on the lower face of the facestock, wherein at least a portion of one layer of the adhesive includes a product made from reacting an epoxidized naturally occurring oil or fat with one or more reagents selected from the group consisting of a dimer acid and a diacid. 
     
     
         20 . A method comprising:
 reacting an epoxidized naturally occurring oil or fat with at least one dimer acid, optionally a diacid, and an acrylic or vinyl functionalized reagent to form a PSA precursor;   adding a photo initiator; and   curing the PSA precursor using UV radiation.