# US 7,744,803 B2 · Photo-crosslinkable polyolefin compositions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,803 B2 - Document ID: US7744803B2 - Status: Granted - Kind: B2 - Application number: 11/680,068 - Filed: 2007-02-28 - Published: 2008-02-21 - Granted: 2010-06-29 - Earliest claimed: 2006-08-02 - Assignees: Shawcor Ltd. - Inventors: Peter Jackson; Eileen Wan - Web page: https://patentgrep.com/patent/US7744803B2 ## CPC - C08J 3/243: {Two or more independent types of crosslinking for one or more polymers} - C08L 23/04: Homopolymers or copolymers of ethene - C08L 23/06: Polyethylene - C08L 23/10: Homopolymers or copolymers of propene - C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers - C08L 51/06: grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond - C09D 151/06: grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond - C08J 2323/00: Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers - C08K 7/14: Glass - C08L 21/00: Compositions of unspecified rubbers - C08L 23/0884: Epoxide-containing esters - C08L 2205/02: containing two or more polymers of the same C08L -group - C08L 2312/06: by radiation - C08L 2314/06: Metallocene or single site catalysts - Y10T 428/31909: Next to second addition polymer from unsaturated monomers - Y10T 428/31938: Polymer of monoethylenically unsaturated hydrocarbon - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A photo-crosslinkable polyolefin composition comprises a polyolefin, a source of functionality receptive to crosslinking by UV radiation, a cationic photoinitiator and optionally includes a free-radical photoinitiator, a crosslinking accelerator or sensitizer, and other additives such as compatibilizers, inorganic fillers, nanofillers, glass, polymeric and ceramic microspheres, glass fibres, flame retardants, antioxidants, stabilizers, processing aids, foaming agents and pigments. A method for manufacturing a UV-crosslinked polyolefin article comprises forming an article by extruding, moulding or otherwise forming the UV-crosslinkable polyolefin composition and subjecting the article to UV radiation on-line with the extrusion, moulding or other forming operation. ## Claims ### Claim 1 A process for preparing an ultraviolet-crosslinked, thermoset article or coating, comprising: (a) forming a blend comprising: (i) a polyolefin selected from one or more members of the group consisting of polyethylene, polypropylene, copolymers of polyethylene, terpolymers of polyethylene and copolymers of polypropylene, wherein the polyolefin includes cationically polymerizable functional groups covalently bonded to the polyolefin; (ii) a cationic photoinitiator in an amount effective to initiate curing of said composition; and (iii) free-radical polymerizable functional groups in an effective amount to accelerate curing of said composition, wherein the free-radical polymerizable functional groups are covalently bonded to the polyolefin; (b) melt processing the blend to produce a melt-processed article or coating having a first set of dimensions; (c) cooling the melt-processed article or coating to a solid state; and (d) crosslinking the melt-processed article or coating by exposure to ultraviolet radiation to thereby produce said ultraviolet-crosslinked, thermoset article, wherein the crosslinking imparts thermoset characteristics to the article or coating such that, when the article or coating is heated to a temperature above the crystalline melting point of the polyolefin, it is softened but does not become liquid. ### Claim 2 (depends on 1) The process of claim 1, further comprising: (e) heating the ultraviolet-crosslinked, thermoset article to a first temperature at which it is softened but not melted; (f) stretching the softened article such that the article is expanded beyond the first set of dimensions; and (g) cooling the stretched article to a second temperature below the temperature at which the article is softened while holding the article in its stretched form. ### Claim 3 (depends on 2) The process of claim 2, wherein the heating step (e), the stretching step (f), and the cooling step (g) are performed on-line immediately following the processing step (b), the cooling step (c), and the crosslinking step (d). ### Claim 4 (depends on 1) The process of claim 1, wherein steps (a) and (b) are performed simultaneously. ### Claim 5 (depends on 1) The process of claim 1, wherein step (a) is performed prior to step (b) using a machine selected from the group consisting of a continuous twin-screw compounder, a kneader and an internal batch mixer. ### Claim 6 (depends on 1) The process of claim 1, wherein melt processing step (b) comprises extruding or molding. ### Claim 7 (depends on 1) The process of claim 1, wherein the ultraviolet radiation has a wavelength of 200-500 nm. ### Claim 8 (depends on 1) The process of claim 1, wherein crosslinking step (d) is performed on-line immediately following the melt processing step (b) and cooling step (c). ### Claim 9 (depends on 1) The process of claim 1, wherein the polyolefin is selected from the group consisting of polyethylene, copolymers of polyethylene and terpolymers of polyethylene. ### Claim 10 (depends on 9) The process of claim 9, wherein the polyethylene is selected from one or more members of the group consisting of very low density polyethylene (VLDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), linear medium density polyethylene (LMDPE) and high density polyethylene (HDPE). ### Claim 11 (depends on 9) The process of claim 9, wherein the copolymers of polyethylene are selected from one or more members of the group consisting of ethylene-propylene, ethylene-butene, ethylene-hexene, ethylene-octene, ethylene vinyl acetate, ethylene vinyl alcohol, ethylene methyl acrylate, ethylene ethyl acrylate, and ethylene butyl acrylate. ### Claim 12 (depends on 9) The process of claim 9, wherein the terpolymers of polyethylene are selected from one or more members of the group consisting of ethylene-methyl acrylate-maleic anhydride terpolymer; ethylene-methyl acrylate-glycidyl methacrylate terpolymer; ethylene-ethyl acrylate-maleic anhydride terpolymer; ethylene-ethyl acrylate-glycidyl methacrylate terpolymer; ethylene-butyl acrylate-maleic anhydride terpolymer; ethylene-butyl acrylate-glycidyl methacrylate terpolymer; ethylene-propylene-diene terpolymers; ethylene-propylene-maleic anhydride terpolymers; and ethylene-propylene-glycidyl methacrylate terpolymers. ### Claim 13 (depends on 1) The process of claim 1, wherein the cationically polymerizable functional groups originate from a reactive compound selected from the group consisting of glycidyl methacrylates, glycidyl ethers, vinyl ethers, divinyl ethers, epoxides, diepoxides, oxazolines, oxetanes, epoxy acrylates, epoxy silanes, epoxy siloxanes, polyols and combinations thereof. ### Claim 14 (depends on 1) The process of claim 1, wherein the polyolefin comprises an ethylene-methyl acrylate-glycidyl methacrylate terpolymer. ### Claim 15 (depends on 1) The process of claim 1, further comprising the step of combining the blend formed in step (a) with a compatibilizer selected from the group consisting of: polyethylenes; polypropylenes; ethylene-propylene copolymers; ethylene-propylene diene elastomers; crystalline propylene-ethylene elastomers; thermoplastic polyolefin elastomers; metallocene polyolefins; cyclic olefin copolymers; polyoctenamers; ethylene-vinyl acetate copolymers; ethylene-vinyl alcohol copolymers; ethylene-alkyl acrylate copolymers; polybutenes; hydrogenated polybutadienes; non-hydrogenated polybutadienes; butyl rubber; polyolefin ionomers; polyolefin nanocomposites; styrene-butadiene block copolymers; styrene-butadiene-styrene block copolymers; styrene-ethylene/propylene-styrene block copolymers; styrene-ethylene/butylene-styrene block copolymers; and combinations thereof. ### Claim 16 (depends on 15) The process of claim 15, wherein the compatibilizer is selected from the group consisting of: polyethylenes, ethylene-propylene copolymers and ethylene-propylene-diene elastomers. ### Claim 17 (depends on 16) The process of claim 16, wherein the compatibilizer is an ethylene-propylene-diene elastomer. ### Claim 18 (depends on 15) The process of claim 15, wherein the compatibilizer comprises from 1-50 percent by weight of the composition. ### Claim 19 (depends on 1) The process of claim 1, wherein the polyolefin comprises from 10-98 percent by weight of the composition. ### Claim 20 (depends on 19) The process of claim 19, wherein the polyolefin comprises from 50-95 percent by weight of the composition. ### Claim 21 (depends on 1) The process of claim 1, wherein the free-radical polymerizable functional groups are selected from one or more members of the group consisting of acrylates and methacrylates. ### Claim 22 (depends on 1) The process of claim 1, wherein the blend formed in step (a) further comprises a free-radical photoinitiator in an effective amount to accelerate curing of said composition. ### Claim 23 (depends on 22) The process of claim 22, wherein the free-radical photoinitiator is selected from one or more members of the group consisting of benzophenones, acetophenones, benzoin ethers, benzils, benzylketals, benzoyl oximes, aminobenzoates, aminoketones, hydroxyketones, ethylamines, ethanolamines, alkylphenones, anthracenes, anthraquinones, anthrachinones, xanthones, thioxanthones, quinones, fluorenones, peroxides, and acylphosphine oxides. ### Claim 24 (depends on 1) The process of claim 1, further comprising the step of combining the blend formed in step (a) with a filler, wherein the filler comprises a metal oxide. ### Claim 25 (depends on 24) The process of claim 24, wherein the metal oxide comprises antimony trioxide. ### Claim 26 A process for preparing an ultraviolet-crosslinked, thermoset article or coating, comprising: (a) forming a blend comprising: (i) a polyolefin comprising an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, wherein the polyolefin includes cationically polymerizable functional groups covalently bonded to the polyolefin; and (ii) a cationic photoinitiator in an amount effective to initiate curing of said composition; (b) melt processing the blend to produce a melt-processed article or coating having a first set of dimensions; (c) cooling the melt-processed article or coating to a solid state; and (d) crosslinking the melt-processed article or coating by exposure to ultraviolet radiation to thereby produce said ultraviolet-crosslinked, thermoset article, wherein the crosslinking imparts thermoset characteristics to the article or coating such that, when the article or coating is heated to a temperature above the crystalline melting point of the polyolefin, it is softened but does not become liquid. ### Claim 27 (depends on 26) The process of claim 26, further comprising: (e) heating the ultraviolet-crosslinked, thermoset article to a first temperature at which it is softened but not melted; (f) stretching the softened article such that the article is expanded beyond the first set of dimensions; and (g) cooling the stretched article to a second temperature below the temperature at which the article is softened while holding the article in its stretched form. ### Claim 28 A process for preparing an ultraviolet-crosslinked, thermoset article or coating, comprising: (a) forming a blend comprising: (i) a polyolefin selected from one or more members of the group consisting of polyethylene, polypropylene, copolymers of polyethylene, terpolymers of polyethylene and copolymers of polypropylene wherein the polyolefin includes cationically polymerizable functional groups covalently bonded to the polyolefin; and (ii) a cationic photoinitiator in an amount effective to initiate curing of said composition; further comprising the step of combining the blend formed in step (a) with an ethylene-propylene-diene elastomer as a compatibilizer; (b) melt processing the blend to produce a melt-processed article or coating having a first set of dimensions; (c) cooling the melt-processed article or coating to a solid state; and (d) crosslinking the melt-processed article or coating by exposure to ultraviolet radiation to thereby produce said ultraviolet-crosslinked, thermoset article, wherein the crosslinking imparts thermoset characteristics to the article or coating such that, when the article or coating is heated to a temperature above the crystalline melting point of the polyolefin, it is softened but does not become liquid. ### Claim 29 (depends on 28) The process of claim 28, further comprising: (e) heating the ultraviolet-crosslinked, thermoset article to a first temperature at which it is softened but not melted; (f) stretching the softened article such that the article is expanded beyond the first set of dimensions; and (g) cooling the stretched article to a second temperature below the temperature at which the article is softened while holding the article in its stretched form. ### Claim 30 (depends on 28) The process of claim 28, wherein the compatibilizer comprises from 1-50 percent by weight of the composition.