# US 7,411,024 B2 · Interpolymer resin particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,411,024 B2 - Document ID: US7411024B2 - Status: Granted - Kind: B2 - Application number: 11/007,678 - Filed: 2004-12-08 - Published: 2005-07-14 - Granted: 2008-08-12 - Earliest claimed: 2003-12-22 - Assignees: NOVA Chemicals Inc. - Inventors: Steven M. Krupinski - Web page: https://patentgrep.com/patent/US7411024B2 ## CPC - C08L 25/00: Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers - C08F 255/00: Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00 - C08F 255/02: on to polymers of olefins having two or three carbon atoms - C08L 23/02: not modified by chemical after-treatment - C08L 25/06: Polystyrene - C08L 2666/06: Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract Interpolymer resin particles comprised of 20% to 60% by weight of uncross-linked polyolefin e.g. polyethylene, polypropylene, and from 40% to 80% by weight based on the weight of the particles of a vinyl aromatic monomer, e.g. styrene, that is polymerized in a suspension process to form an interpenetrating network of polyolefin with polymerized vinyl aromatic monomer particles and having a gel content of 0 to 1.5% by weight based on the weight of the particles for improved processability in end-use applications and improved ESCR properties. The interpolymer resin particles have a VICAT softening temperature from about 90° C. to about 115° C., and a melt index from 0.2 to 35.0 g/10 minutes (Condition G). The particles can be mixed with a blowing agent to form extruded foam articles, such as foam board, and can be used in extrusion, injection molding, rotomolding, and thermoforming processes to form a layer, e.g. sheet, film, and as a tie layer in multi-layer structures to bind adjacent layers consisting of incompatible polymers, i.e. polystyrene and polyethylene for improved rigidity in multi-layer structures. ## Claims ### Claim 1 A process for forming interpolymer resin particles comprising: a) suspending in an aqueous medium from about 20% to 60% by weight of polyolefin resin particles having a VICAT softening temperature greater than 85° C. and a melt index of about 2.1 g/10 minutes (Condition I, 190° C., 2.16 kg); b) adding to the aqueous suspension a first vinyl aromatic monomer composition comprising vinyl aromatic monomer and a polymerization initiator for polymerizing the vinyl aromatic monomer within the polyolefin resin particles; c) adding to the aqueous suspension a second vinyl aromatic monomer composition comprising vinyl aromatic monomer, said second vinyl aromatic monomer composition being substantially free of polymerization initiator, said second vinyl aromatic monomer composition being added to said aqueous suspension after addition of said first vinyl aromatic monomer composition, said first vinyl aromatic monomer composition and said second vinyl aromatic monomer composition together providing from 40 to 80 percent by weight of vinyl aromatic monomer, based on total weight of polyolefin resin particles and vinyl aromatic monomer; and d) polymerizing said vinyl aromatic monomer within said polyolefin resin particles, thereby forming said interpolymer resin particles, polymerization of said vinyl aromatic monomer being performed in the substantial absence of cross-linking agent such that said interpolymer resin particles have a gel content ranging from about 0 to about 1.5% by weight, based on the weight of the interpolymer resin particles, wherein said interpolymer resin particles have a VICAT softening temperature ranging from about 90° C. to about 115° C. and a melt index value ranging from about 0.2 to about 35g/10 minutes (Condition G). ### Claim 2 (depends on 1) A process of claim 1 wherein said interpolymer resin particles have a VICAT softening temperature from about 90° C. to about 105° C., and a gel content ranging from about 0 to about 0.8% by weight, based on the weight of the interpolymer resin particles. ### Claim 3 (depends on 1) A process of claim 1 wherein said weight of said polyolefin particles is about 30% by weight based on the weight of said interpolymer particles, and said weight of said vinyl aromatic monomer is about 70% by weight based on the weight of said interpolymer particles. ### Claim 4 (depends on 1) A process of claim 1 wherein said weight of said polyolefin resin particles is about 40% by weight based on the weight of said interpolymer particles, and said weight of said vinyl aromatic monomer is about 60% by weight based on the weight of interpolymer particles. ### Claim 5 (depends on 1) A process of claim 1 wherein said weight of said polyolefin resin particles is about 50% by weight based on the weight of said interpolymer particles, and said weight of said vinyl aromatic monomer is about 50% by weight based on the weight of said interpolymer particles. ### Claim 6 (depends on 1) A process of claim 1 wherein said vinyl aromatic monomer is selected from the group consisting of styrene, alpha-methylstyrene, ethylstyrene, chlorostyrene, bromostyrene, vinyltoluene, vinylbenzene, isopropylxylene, and mixtures thereof. ### Claim 7 (depends on 6) A process of claim 6 wherein said polyolefin resin of said polyolefin resin particles is selected from the group consisting of polyethylene, polypropylene, thermoplastic olefins, and thermoplastic elastomers resins. ### Claim 8 (depends on 7) A process of claim 7 wherein said vinyl aromatic monomer is styrene and wherein said polyolefin resin of said polyolefin resin particles is selected from the group consisting of polyethylene and polypropylene resins. ### Claim 9 (depends on 7) A process of claim 7 wherein said polyethylene resin is selected from the group consisting of low-density polyethylene and ethylene vinyl acetate copolymer. ### Claim 10 (depends on 1) A process of claim 1 wherein said interpolymer resin particles are pellets and said each pellet weighs from about 8 milligrams to 20 milligrams.