Plasticized uv/eb cured coatings

Abstract

A plasticized ultraviolet or electron beam (UV/EB) cationically cured coating, such as a release layer or print from UV/EB cured inks, comprises polymers with a reactive plasticizer incorporated therein. The cured coating contains the plasticizing additives permanently attached to the polymer matrix, locking them in place, and permanently flexibilizing the cured coating. The cured coating finds use on varied substrates including printable substrates used in conventional printers and those with release layers for adhesive labels. Coating formulations which form these cationically cured coatings comprise cationically polymerizable monomers and/or oligomers, a reactive plasticizer which is food grade, cosmetic grade, medical grade or biologically benign when incorporated in the polymer backbone, and a catalyst.

1 . A plasticized ultraviolet or electron beam (UV/EB) cationically cured coating comprised of polymers formed from:
 A. cationically polymerized monomers and/or oligomers, which are epoxy monomers, epoxy oligomers, oxetane monomers, oxetane oligomers, vinyl ether monomers, vinyl ether oligomers, or combinations thereof, and   B. at least one reactive plasticizer which is permanently integrated within said plasticized ultraviolet or electron beam cationically cured coating, wherein the at least one reactive plasticizer possesses one or more functional groups that react as chain transfer groups or chain terminating groups with cationically polymerized monomers and/or oligomers, wherein the at least one reactive plasticizer is completely incorporated into the polymer backbone and is biologically benign in that state and wherein the at least one reactive plasticizer is:   A. polypropanediol dimer dilinoleate.   B. dimer dilinoleyl dimer dilinoleate,   C. polyglyceryl-6 behenate,   D. polyglyceryl-6 polyricinoleate,   E. diisopropyl dimer dilinoleate or combinations of two or more thereof.   
     
     
         2 . The coating of  claim 1 , wherein the polymers are formed from components A. and B. and at least one coupling agent having the formula R 1   n —Si—OR 2   (4-n) , where n is 2 and R 1  contains a cationic-reactive group which is a cycloaliphatic epoxy, vinyl ether, or oxetane moiety, and R 2  is an optionally substituted C 1-6 hydrocarbon. 
     
     
         3 . The coating of  claim 2 , wherein the at least one or more coupling agents is:
 A. 2-(3,4-epoxycyclohexyl)ethyl methyl diethoxy silane,   B. 2-(3,4-epoxycyclohexyl)ethyl triethoxy silane,   C. 2-(3,4-epoxycyclohexyl)ethyl trimethoxy silane, or   D. 5,6-epoxyhexyl triethoxy silane.   
     
     
         4 . The coating of  claim 1 , wherein the polymers are formed from components A. and B. and a cationic photoinitiator activated by UV/EB radiation. 
     
     
         5 . The coating of  claim 1 , wherein the coating further comprises at least one of colorants, pigment dispersants, defoamers, and fillers. 
     
     
         6 . The coating of  claim 1 , wherein the coating forms a release layer for an adhesive label. 
     
     
         7 . The coating of  claim 1 , wherein the epoxy monomers or epoxy oligomers have a viscosity of 25,000 cps or less at 25° C., in the absence of a solvent. 
     
     
         8 . The coating of  claim 1 , wherein the oxetane monomers or oxetane oligomers are of the formula: 
       
         
           
           
               
               
           
         
         wherein R, R 1 , R 2 , and R 3  are each, independently, H or C 1-8  alkyl with the proviso that at least one of R 1  and R 2  are non-hydrogen substituents. 
       
     
     
         9 . The coating of  claim 8 , wherein at least one of R 1  and R 2  is —CH 2 OH or —CH 2 (OH)(CH 3 ). 
     
     
         10 . The coating of  claim 8 , wherein the oxetane monomers or oxetane oligomers have a viscosity of 25,000 cps or less at 25° C., in the absence of a solvent, 
     
     
         11 . The coating of  claim 1 , wherein vinyl ether monomers or vinyl ether oligomers are of the formula: 
       
         
           
           
               
               
           
         
         wherein R and R′ are each, independently, H or C 1-8  alkyl. 
       
     
     
         12 . The coating of  claim 11 , wherein R and R′ are each H. 
     
     
         13 . The coating of  claim 11 , wherein at least one of R and R′ is CH 3 . 
     
     
         14 . The coating of  claim 11 , wherein the vinyl ether monomers or vinyl ether oligomers have a viscosity of 25,000 cps or less at 25° C., in the absence of a solvent. 
     
     
         15 . A plasticized ultraviolet or electron beam (UV/EB) canonically cured coating comprised of polymers formed from:
 A. canonically polymerized monomers and/or oligomers, which are epoxy monomers, epoxy oligomers, oxetane monomers, oxetane oligomers, vinyl ether monomers, vinyl ether oligomers, or combinations thereof, and   B. at least one reactive plasticizer which is permanently integrated within said plasticized ultraviolet or electron beam canonically cured coating, wherein the at least one reactive plasticizer possesses one or more functional groups that react as chain transfer groups or chain terminating groups with canonically polymerized monomers and/or oligomers, wherein the at least one reactive plasticizer is completely incorporated into the polymer backbone and is biologically benign in that state, wherein the plasticized ultraviolet or electron beam (UV/EB) canonically cured coating additionally comprises at least one coupling agent having the formula R 1   n —Si—OR 2   (4-n) , where n is 2 and contains a cationic-reactive group which is a cycloaliphatic epoxy, vinyl ether, or oxetane moiety, and re is an optionally substituted C 1-6 hydrocarbon, wherein said plasticized ultraviolet or electron beam cationically cured coating is a printed ink image cured by UV or EB radiation.   
     
     
         16 . The coating of  claim 15 , wherein the at least one reactive plasticizer is:
 A. polypropanediol dimer dilinoleate,   B. dimer dilinoleyl dimer dilinoleate,   C. polyglyceryl-6 behenate,   D. polyglyceryl-6 polyricinoleate,   E. diisopropyl dimer dilinoleate or combinations of two or more thereof.   
     
     
         17 . A plasticized ultraviolet or electron beam (UV/EB) cationically cured coating comprised of polymers formed from:
 A. cationically polymerizable monomers and/or oligomers selected from epoxy monomers, epoxy oligomers, oxetane monomers, oxetane oligomers, vinyl ether monomers, vinyl ether oligomers, or combinations thereof, and   B. at least one reactive plasticizer, wherein the at least one reactive plasticizer possesses two or more functional groups that react as chain transfer groups or chain terminating groups with the cationically polymerized monomers and/or oligomers, wherein the reactive plasticizer was completely incorporated into the polymer backbone and is biologically benign in that state,   C. a cationic photoinitiator activated by UV/EB radiation, wherein the at least one reactive plasticizer is a polydimethyl silicone polymer with diol end groups which completely incorporates in the polymer backbone and is biologically benign in that state, wherein the UV/EB cationically curable coating formulation additionally comprises at least one coupling agent having the formula R 1   n —Si—OR 2   (4-n) , where n is an integer of 1 or 2 R I  contains a cationic-reactive group which is a cycloaliphatic epoxy, vinyl ether, or oxetane moiety, and R 2  is an optionally substituted C 1-6 hydrocarbon.   
     
     
         18 . The coating of  claim 17 , wherein the at least one or more coupling agents is:
 A. 2-(3,4-epoxycyclohexyl)ethyl methyl diethoxy silane,   B. 2-(3,4-epoxycyclohexyl)ethyl triethoxy silane,   C. 2-(3,4-epoxycyclohexyl)ethyl trimethoxy silane, or   D. 5,6-epoxyhexyl triethoxy silane.   
     
     
         19 . The coating of  claim 17 , which is an ink. 
     
     
         20 . The coating of  claim 17 , wherein the coating forms a release layer for an adhesive label.