# US 8,569,417 B2 · Modified polyolefins > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,417 B2 - Document ID: US8569417B2 - Status: Granted - Kind: B2 - Application number: 13/001,668 - Filed: 2009-07-02 - Published: 2011-08-04 - Granted: 2013-10-29 - Earliest claimed: 2008-07-03 - Assignees: Dow Corning Corporation - Applicants: Michael Backer; Francois De Buyl; Valerie Smits; Damien Deheunynck - Inventors: Michael Backer; Francois De Buyl; Valerie Smits; Damien Deheunynck - Web page: https://patentgrep.com/patent/US8569417B2 ## CPC - 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 - C08F 255/08: on to polymers of olefins having four or more carbon atoms - 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 - C09J 151/06: grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond - C08L 2666/02: Organic macromolecular compounds, natural resins, waxes or and bituminous materials - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - 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) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) ## Abstract The invention relates to a process for grafting hydrolysable silane groups to a polyolefin in which ethylene units, if present, form less than 50% by weight of the total polyolefin. The polyolefin is reacted with an unsaturated silane, having at least one hydrolysable group bonded to Si, or a hydrolysate thereof, in the presence of means capable of generating free radical sites in the polyolefin. The unsaturated silane has the formula R″—CH═CH—Z (I) or R″—C≡C—Z (II) in which Z represents an electron-withdrawing moiety substituted by a —SiRaR′(3-a) group wherein R represents a hydrolysable group; R′ represents a hydrocarbyl group having 1 to 6 carbon atoms; a has a value in the range 1 to 3 inclusive; and R″ represents hydrogen or a group having an electron withdrawing or any other activation effect with respect to the —CH═CH— or —C≡C— bond. The use of an unsaturated silane of the formula R″—CH═CH—Z (I) or R″—C≡C—Z (II) in carrying out the grafting reaction on the polyolefin may give enhanced grafting yield compared to grafting with an olefinically unsaturated silane such as vinyltrimethoxysilane not containing an electron withdrawing moiety Z. The invention permits to provide a silane-modified polyolefin having a high grafting efficiency while limiting/preventing polymer degradation by chain scission. The silane-modified polyolefin can be further reacted with a polar surface, a filler or a polar polymer or reacted on itself to crosslink the polyolefin and obtain enhanced physical properties of the composites made thereof. ## Claims ### Claim 1 A process for grafting hydrolysable silane groups to a polyolefin in which ethylene units, if present, form less than 50% by weight of the total polyolefin, the process comprising reacting the polyolefin with an unsaturated silane, having at least one hydrolysable group bonded to Si, or a hydrolysate thereof, in the presence of means capable of generating free radical sites in the polyolefin and a co-agent comprising a sorbate ester, a 2,4-pentadienoate, or a cyclic derivative thereof, characterised in that the silane has the formula R″—CH═CH—Z (I) or R″—C≡C—Z (II) in which Z represents an electron-withdrawing moiety substituted by a —SiRaR′(3-a) group wherein R represents a hydrolysable group; R′ represents a hydrocarbyl group having 1 to 6 carbon atoms; a has a value in the range 1 to 3 inclusive; and R″ represents hydrogen or a group having an electron withdrawing effect or any other activation effect with respect to the —CH═CH— or —C≡C— bond. ### Claim 2 (depends on 1) A process according to claim 1 characterised in that the polyolefin comprises at least 50% by weight units of an olefin having 3 to 8 carbon atoms. ### Claim 3 (depends on 1) A process according to claim 1 characterised in that the grafting reaction is carried out in the presence of a co-agent which inhibits polymer degradation by beta scission in the presence of a compound capable of generating free radical sites in the polyolefin. ### Claim 4 (depends on 1) A process according to claim 1 characterised in that the co-agent is present at 0.1 to 15.0% by weight of the total composition. ### Claim 5 (depends on 1) A process according to claim 1 characterised in that each group R in the unsaturated silane (I) or (II) is an alkoxy group. ### Claim 6 (depends on 1) A process according to claim 1 characterised in that the unsaturated silane (I) or (II) is partially hydrolyzed and condensed into oligomers. ### Claim 7 (depends on 1) A process according to claim 1 characterised in that the silane has the formula R″—CH═CH—X—Y—SiRaR′(3-a) (III) or R″—C≡C—X—Y—SiRaR′(3-a) (IV) in which X represents a chemical linkage having an electron withdrawing effect with respect to the —CH═CH— or —C≡C— bond, and Y represents a divalent organic spacer linkage comprising at least one carbon atom separating the linkage X from the Si atom. ### Claim 8 (depends on 7) A process according to claim 7 characterised in that the silane has the formula R″—CH═CH—X—Y—SiRaR′(3-a) (III) and the moiety R″—CH═CH—X—Y— is an acryloxyalkyl group. ### Claim 9 (depends on 8) A process according to claim 8 characterised in that the unsaturated silane (I) comprises γ-acryloxypropyltrimethoxysilane and/or acryloxymethyltrimethoxysilane. ### Claim 10 (depends on 9) A process according to claim 9 characterised in that the unsaturated silane (I) comprises a blend of γ-acryloxypropyltrimethoxysilane with acryloxymethyltrimethoxysilane or a blend or γ-acryloxypropyltrimethoxysilane or acryloxymethyltrimethoxysilane with vinyltrimethoxysilane or methacryloxytrimethoxysilane. ### Claim 11 (depends on 9) A process according to claim 9 characterised in that the group R″ in the unsaturated silane (III) and (IV) is an electron withdrawing group of the formula —X—Y—SiRaR′(3-a). ### Claim 12 (depends on 11) A process according to claim 11 characterised in that the unsaturated silane (III) comprises a bis(trialkoxysilylalkyl) fumarate and/or a bis(trialkoxysilylalkyl) maleate. ### Claim 13 (depends on 1) A process according to claim 1 characterised in that the unsaturated silane (I) or (II) is present at 0.5 to 15.0% by weight of the total composition. ### Claim 14 (depends on 1) A process according to claim 1 characterised in that an organic peroxide compound capable of generating free radical sites in the polymer is present at 0.01 to 2% by weight of the total composition. ### Claim 15 (depends on 1) A process according to claim 1 characterised in that the unsaturated silane (I) or (II) is deposited on a filler before being reacted with the polymer. ### Claim 16 (depends on 1) A process according to claim 1 characterised in that the polymer, unsaturated silane (I) or (II) and filler are reacted in situ. ### Claim 17 A polyolefin grafted with hydrolysable silane groups in which less than 50% by weight of the total units in the polyolefin being ethylene units, characterised in that the polyolefin contains grafted moieties of the formula R″—CH(PP)—CH2—Z and/or grafted moieties of the formula R″—CH2—CH(PP)—Z wherein Z represents an electron-withdrawing moiety substituted by a —SiRaR′(3-a) group wherein R represents a hydrolysable group; R′ represents a hydrocarbyl group having 1 to 6 carbon atoms; a has a value in the range 1 to 3 inclusive; R″ represents hydrogen or a group having an electron withdrawing effect or any other activation effect and PP represents a polyolefin chain in which less than 50% by weight of the total units in the polyolefin are ethylene units, and wherein the grafted moieties are grafted onto the polyolefin in the presence of a co-agent comprising a sorbate ester, a 2,4-pentadienoate, or a cyclic derivative thereof. ### Claim 18 (depends on 17) A process for crosslinking a polymer in which ethylene units, if present, form less than 50% by weight of the total polymer, characterised in that the grafted polymer according to claim 17 is exposed to moisture in either the presence or the absence of a silanol condensation catalyst. ### Claim 19 (depends on 18) A process according to claim 18 characterised in that the grafted polymer is shaped into an article and subsequently crosslinked by exposure to moisture. ### Claim 20 (depends on 17) A process for forming a foamed polymer, characterised by adding a blowing agent, moisture and condensation catalyst together to the grafted polymer according to claim 17.