# US 11,028,256 B2 · Silica-containing rubber compositions containing specified coupling agents and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,256 B2 - Document ID: US11028256B2 - Status: Granted - Kind: B2 - Application number: 16/708,355 - Filed: 2019-12-09 - Published: 2020-04-23 - Granted: 2021-06-08 - Earliest claimed: 2014-09-24 - Assignees: Bridgestone Americas Tire Operations, LLC - Applicants: Bridgestone Americas Tire Operations, LLC - Inventors: Seth M. Miller - Web page: https://patentgrep.com/patent/US11028256B2 ## CPC - C08L 9/06: Copolymers with styrene - B60C 1/0016: {Compositions of the tread} - C08K 3/36: Silica - C08K 5/5425: containing at least one C=C bond - C08K 5/548: containing sulfur {(C08K5/5477 takes precedence)} - C08L 7/00: Compositions of natural rubber - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - C08L 15/00: Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence) - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2205/03: containing three or more polymers in a blend - C08L 2205/035: containing four or more polymers in a blend - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract Disclosed herein are rubber compositions comprising a conjugated diene-containing polymer, a reinforcing filler including silica, a bi-functional silane coupling agent, and an unsaturated, non-sulfur silane coupling agent, where the ratio of the bi-functional silane coupling agent to the unsaturated, non-sulfur silane coupling agent is from about 5:1 to about 20:1. Also disclosed are related methods which include both in-situ reaction of the silica filler and the unsaturated, non-sulfur silane coupling agent and pre-reacting of at least a portion of the silica filler and at least a portion of the unsaturated, non-sulfur silane coupling agent. ## Claims ### Claim 1 A tire rubber composition comprising: (a) 100 phr of at least one conjugated diene-containing polymer, (b) about 50 to about 120 phr reinforcing filler comprising silica or silica in combination with carbon black, (c) a bi-functional sulfur-containing silane coupling agent, and (d) an unsaturated, non-sulfur silane coupling agent, wherein the ratio of (c) to (d) is from about 5:1 to about 20:1 and wherein the bi-functional sulfur-containing silane coupling agent is a mercapto silane compound, a blocked mercapto silane compound, or a disulfide-based alkoxy-containing silane compound, and the unsaturated, non-sulfur silane coupling agent (d) has the formula (R1Lm)nSi(OR2)4−n, where n is an integer selected from 0 or 1, R1 is selected from (iv) aryl having 6-14 carbon atoms and (v) aralkyl having 6-14 carbon atoms; L is a divalent hydrocarbyl having 1-5 carbon atoms where m is 1, and R2 is selected from hydrocarbyl having 1-6 carbon atoms. ### Claim 2 (depends on 1) The tire rubber composition of claim 1, wherein the bi-functional sulfur-containing silane coupling agent is present in an amount of 1 to 20 phr, and the unsaturated, non-sulfur silane coupling agent is present in an amount of 0.05 to 4 phr. ### Claim 3 (depends on 1) The tire rubber composition of claim 1, wherein the amount of carbon black filler is no more than 30% by weight of the total reinforcing filler. ### Claim 4 (depends on 1) The tire rubber composition of claim 1, wherein the bi-functional sulfur-containing silane coupling agent (c) is a disulfide-based alkoxy-containing silane compound. ### Claim 5 (depends on 1) The tire rubber composition of claim 1, wherein R1 is (iv). ### Claim 6 (depends on 1) The tire rubber composition of claim 1, wherein R1 is (v). ### Claim 7 (depends on 1) The tire rubber composition of claim 1, wherein the ratio of (c) to (d) is from about 7:1 to about 10:1. ### Claim 8 (depends on 1) The tire rubber composition of claim 1, wherein the at least one conjugated diene-containing polymer includes natural rubber. ### Claim 9 (depends on 1) The tire rubber composition of claim 1, wherein the at least one conjugated diene-containing polymer includes 10-90 phr of a functionalized polymer. ### Claim 10 (depends on 9) The tire rubber composition of claim 9, wherein the functionalized polymer contains a silica-reactive functional group. ### Claim 11 (depends on 1) The tire rubber composition of claim 1, wherein 100 phr of the at least one conjugated diene-containing polymer is selected from the group consisting of polybutadiene, styrene-butadiene, natural rubber, polyisoprene, and combinations thereof. ### Claim 12 A tire rubber composition comprising: 100 phr of at least one conjugated diene-containing polymer, a pre-reacted combination of reinforcing silica filler and an unsaturated, non-sulfur silane coupling agent, and a bi-functional sulfur-containing silane coupling agent, wherein a total of about 50 to about 120 phr of reinforcing filler comprising the reinforcing silica filler or reinforcing silica filler in combination with carbon black is used, the ratio of the bi-functional sulfur-containing silane coupling agent to unsaturated, non-sulfur silane coupling agent is from about 5:1 to about 20:1, wherein the bi-functional sulfur-containing silane coupling agent is a mercapto silane compound, a blocked mercapto silane compound, or a disulfide-based alkoxy-containing silane compound, and the unsaturated, non-sulfur silane coupling agent (d) has the formula (R1Lm)nSi(OR2)4−n, where n is an integer selected from 0 or 1, R1 is selected from (iv) aryl having 6-14 carbon atoms and (v) aralkyl having 6-14 carbon atoms; L is a divalent hydrocarbyl having 1-5 carbon atoms where m is 1, and R2 is selected from hydrocarbyl having 1-6 carbon atoms. ### Claim 13 (depends on 12) The tire rubber composition of claim 12, wherein the bi-functional sulfur-containing silane coupling agent is present in an amount of 1 to 20 phr, and the unsaturated, non-sulfur silane coupling agent is present in an amount of 0.05 to 4 phr. ### Claim 14 (depends on 13) The tire rubber composition of claim 13, wherein the unsaturated, non-sulfur silane coupling agent is triethoxyphenylsilane. ### Claim 15 (depends on 14) The tire rubber composition of claim 14, wherein the bi-functional sulfur-containing silane coupling agent is a mercapto silane compound. ### Claim 16 (depends on 12) The tire rubber composition of claim 12, wherein R1 is (iv). ### Claim 17 (depends on 12) The tire rubber composition of claim 12, wherein the unsaturated, non-sulfur silane coupling agent is triethoxyphenylsilane. ### Claim 18 (depends on 12) The tire rubber composition of claim 12, wherein the bi-functional sulfur-containing silane coupling agent is a mercapto silane compound.