Plasticized UV/EB cured coatings
View Patent ↗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 coated substrate comprising a substrate and a plasticized ultraviolet or electron beam (UV/EB) cationically cured coating, wherein the plasticized ultraviolet or electron bean (UV/EB) cationically cured coating is 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 wherein the at least one reactive plasticizer is:
A. polypropanediol dimer dilinoleate,
B. dimer dilinoleyl dimer dilinoleate,
C. polyglyceryl-6 behenate,
D. polyglyceryl-6 polyricinaleate,
E. diisopropyl dimer dilinoleate or a combination thereof.
2. A coated substrate comprising a substrate and a plasticized ultraviolet or electron beam (UV/EB) cationically cured coating, wherein the plasticized ultraviolet or electron bean (UV/EB) cationically cured coating is 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, wherein the plasticized ultraviolet or electron beam (UV/EB) cationically cured coating additionally comprises at least one coupling agent having the formula R i 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, wherein said plasticized ultraviolet or electron beam cationically cured coating is a printed ink image cured by UV or EB radiation.
3. A UV/EB cationically curable coating formulation which comprises
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 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, or
E. diisopropyl dimer dilinoleate.
4. The UV/EB cationically curable coating formulation of claim 3 which is an ink.
5. The UV/EB cationically curable coating formulation of claim 3 which forms a release layer for an adhesive label.
6. A UV/EB cationically curable coating formulation which comprises:
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 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.
7. The UV/EB cationically curable coating formulation of claim 6 wherein the at least one coupling agent is
A. 2-(3,4-epoxycyclohexyl)ethy lmethy ldiethoxy silane,
B. 2-(3,4-epoxycyclohexyl)ethy ltriethoxy silane,
C. 2-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, or
D. 5,6-epoxyhexyl triethoxy silane.