# US 2020/0399442 A1 · Elastomer composition comprising a filler at least partially covered by silica > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0399442 A1 - Document ID: US20200399442A1 - Status: Published application - Kind: A1 - Application number: 16/062,354 - Filed: 2016-12-15 - Published: 2020-12-24 - Earliest claimed: 2015-12-17 - Assignees: Compagnie Generale Des Etablissements Michelin - Applicants: Compagnie Generale Des Etablissements Michelin - Inventors: Olivier GONCALVES; Cecile BELIN - Web page: https://patentgrep.com/patent/US20200399442A1 ## CPC - C08K 9/02: Ingredients treated with inorganic substances - C08K 9/10: Encapsulated ingredients - B60C 1/0016: {Compositions of the tread} - C08J 3/2053: {the additives only being premixed with a liquid phase} - C08J 3/215: at least one additive being also premixed with a liquid phase - C08K 3/04: Carbon - C08K 3/36: Silica - B60C 2200/06: for heavy duty vehicles - C08J 2307/02: Latex - C08J 2309/08: Latex - C08J 2309/10: Latex (C08J2309/04, C08J2309/08 take precedence) - C08K 2201/014: Additives containing two or more different additives of the same subgroup in C08K - C08K 2201/019: the composition being defined by the absence of a certain additive - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - 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) ## Abstract A rubber composition based on at least one diene elastomer, a reinforcing filler predominantly comprising a filler covered at least partially by silica and a crosslinking system. The dispersion of the filler in the elastomeric matrix has a Z score greater than or equal to 70, and the composition is devoid of agent for coupling the filler with the elastomer. ## Claims ### Claim 1 A rubber composition based on at least one diene elastomer, a reinforcing filler predominantly comprising a filler covered at least partially by silica and a crosslinking system, wherein the dispersion of the filler in the elastomeric matrix has a Z score greater than or equal to 70 and wherein the composition is devoid of agent for coupling the filler with the elastomer. ### Claim 2 (depends on 1) The composition according to claim 1, the filler covered at least partially by silica being chosen from carbon black, metal hydroxides, especially magnesium or aluminium hydroxides, and crosslinked polymer particles. ### Claim 3 (depends on 2) The composition according to claim 2, in which the filler at least partially covered by silica consists of carbon black. ### Claim 4 (depends on 1) The composition according to claim 1, in which the filler covered at least partially by silica represents more than 60% by weight of the reinforcing filler. ### Claim 5 (depends on 3) The composition according to claim 3, in which the carbon black covered at least partially by silica is used at a content ranging from 30 to 90 phr. ### Claim 6 (depends on 1) The composition according to claim 1, in which the filler covered at least partially by silica is used in a blend with carbon black. ### Claim 7 (depends on 1) The composition according to claim 1, in which the filler covered at least partially by silica is used in a blend with silica. ### Claim 8 (depends on 6) The composition according to claim 6, in which the total content of reinforcing filler of the composition varies from 35 to 75 phr, the content of carbon black or of silica varying from 1 to 35 phr. ### Claim 9 (depends on 1) The composition according to claim 1, in which the filler covered at least partially by silica represents more than 90% by weight of the reinforcing filler. ### Claim 10 (depends on 1) The composition according to claim 1, in which the filler covered at least partially by silica is the only reinforcing filler of the composition. ### Claim 11 (depends on 1) The composition according to claim 1, in which the diene elastomer is selected from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers and mixtures of these elastomers. ### Claim 12 (depends on 11) The composition according to claim 11, in which the diene elastomer is a natural rubber. ### Claim 13 (depends on 1) The composition according to claim 1, which comprises less than 15 phr of plasticizing agents, preferably less than 5 phr. ### Claim 14 A process for preparing a composition based on at least one diene elastomer, a reinforcing filler predominantly comprising a filler covered at least partially by silica and a crosslinking system, the dispersion of the filler in the elastomeric matrix being a Z score greater than or equal to 70 and the composition being devoid of agent for coupling the filler with the elastomer: preparing a masterbatch comprising the diene elastomer and the filler covered at least partially by silica, this first masterbatch exhibiting a dispersion of the filler in the elastomeric matrix having a Z score of greater than or equal to 70, incorporating the other constituents of the composition, with the exception of the crosslinking system, into the first masterbatch in a mixer, everything being kneaded thermomechanically until a maximum temperature of between 130° C. and 200° C. is reached, cooling the combined mixture to a temperature of less than 100° C., subsequently incorporating the crosslinking system, and kneading everything up to a maximum temperature of less than 120° C. ### Claim 15 (depends on 14) The process according to claim 14, in which the masterbatch is produced in the liquid phase from at least one elastomer latex and a dispersion of filler covered at least partially by silica. ### Claim 16 (depends on 15) The process according to claim 15, in which the masterbatch is produced according to the following successive steps: feeding a continuous stream of a diene elastomer latex to a compounding region of a coagulation reactor defining an elongated coagulation region extending between the compounding region and an outlet orifice, feeding a continuous stream of a fluid comprising a filler under pressure into the compounding region of a coagulation reactor in order to form a coagulated mixture, drying the coagulum obtained previously so as to recover the masterbatch. ### Claim 17 (depends on 14) The process according to claim 14, in which the diene elastomer is selected from the group consisting of polybutadienes, natural rubber, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers and the mixtures of these elastomers. ### Claim 18 (depends on 17) The process according to claim 17, in which the diene elastomer is a natural rubber. ### Claim 19 (depends on 14) The process according to claim 14, in which the filler covered at least partially by silica consists of carbon black. ### Claim 20 (depends on 14) The process according to claim 14, in which the content of filler covered at least partially by silica varies from 35 to 75 phr. ### Claim 21 (depends on 1) A finished or semi-finished article comprising a composition according to claim 1. ### Claim 22 (depends on 1) A tire tread comprising a composition according to claim 1. ### Claim 23 (depends on 1) The tire or semi-finished product comprising the composition according to claim 1. ### Claim 24 (depends on 23) The tire according to claim 23, intended to equip vehicles carrying heavy loads and running at sustained speed.