Bridgestone Corporation

Narukuni Hirata

Shojiro Kaita

Yusuke Yamagata

Tomoe Tanabe

Satoru Watanabe

Shinichi Eguchi

Ryuji Izumoto

Madoka Kimura

Takeshi Oba

Daisuke Sugio

Hideshi Yanagi

Minoshima Haruki

Haruki Minoshima

A method for manufacturing a conjugated diene polymer that can increase the robustness of a polymerization reaction system is provided. Also, a conjugated diene polymer, with a high cis-1,4-bond content, that is manufactured by this method for manufacturing is provided. A method for manufacturing a conjugated diene polymer includes polymerizing a conjugated diene monomer using a polymerization catalyst composition including a rare earth element compound and a compound having a cyclopentadiene skeleton, and a conjugated diene polymer manufactured with this method for manufacturing has a cis-1,4-bond content of 95% or greater.

Method for manufacturing conjugated diene polymer, conjugated diene polymer, rubber composition, and tire

This disclosure is to provide a method for preparing a terminal-modified conjugated diene polymer which achieves an extremely high compounding amount of cis-1,4 without complicated preparing conditions, a terminal-modified conjugated diene polymer obtained via the method, a rubber composition containing the terminal-modified conjugated diene polymer, and a tire using the rubber composition. This disclosure is A method for preparing a terminal-modified conjugated diene polymer comprising: polymerizing a conjugated diene compound by using a polymerization catalyst composition and modifying a polymer obtained via the polymerization by using a modifier, wherein the polymerization catalyst composition contains a rare earth element compound, and a coordination compound having a cyclopentadiene skeleton selected from substituted or unsubstituted cyclopentadienes, substituted or unsubstituted indenes, and substituted or unsubstituted fluorenes, and wherein the polymerization and modification is performed in a one-pot way.

Method for preparing terminal-modified conjugated diene polymer, terminal-modified conjugated diene polymer, rubber composition and tire

The invention is a process for producing a rubber composition containing at least one rubber component (A) selected from natural rubbers and synthetic diene rubbers, a filler containing an inorganic filler (B), a silane coupling agent (C) and a vulcanization accelerator (D), wherein the rubber composition is kneaded in multiple stages, the rubber component (A), all or a portion of the inorganic filler (B), all or a portion of the silane coupling agent (C) and the vulcanization accelerator (D) are added and kneaded in the first stage of kneading, and the specific energy for kneading in the first stage is from 0.05 to 1.50 kWh/kg. The specific energy is obtained by dividing the power consumption by the motor in the kneading device in the first stage of kneading by the total mass of the rubber composition therein.

Method for producing rubber composition

A method for manufacturing a puncture-sealing agent, which effectively prevents gelification of the puncture-sealing agent caused by agglomerates of rubber latex and that can enhance the productivity of the puncture-sealing agent is provided. The manufacturing method includes a first mixing process of mixing an antifreeze liquid with water to obtain a mixture liquid A1; a second mixing process of adding the mixture liquid A1 dropwise into a rubber latex that is being stirred and performing mixing to obtain a mixture liquid A2, while increasing the stirring speed as a liquid amount of the mixture liquid A2 increases; and a third mixing process of mixing the mixture liquid A2 with a tackifier. An amount of variation in the stirring speed is preferably from 0.1 rpm/mm to 6.0 rpm/mm, and a dropwise-addition rate of the mixture liquid A1 is preferably from 0.5 kg/min to 500 kg/min.

Method of manufacturing puncture-sealing agent

A sealing agent stock solutionis prepared by preparing a mixed solutionby mixing a rubber latex, a resin emulsion and a surfactant, and a predetermined amount of water in a solution preparation vessel, followed by adding an anti-freeze agentto the mixed solution. The sealing agent stock solutionis held (left standing still) at least over for 24 hr or more and preferably over for 48 hr or more without stirring in the solution preparation vessel, followed by filtering the sealing agent stock solutionwith a filter membermade of a mesh filter having the mesh number from 50 to 400 mesh to remove latex aggregatesgenerated in the sealing agent stock solution, and thereby a sealing agentthat does not contain the latex aggregatesis produced.

Process for production of sealing agent

A method for producing a puncture sealant, including: performing a first mixing to mix an anti-freezing agent and water; performing a second mixing to mix a mixed liquid obtained from the first mixing and a rubber latex; and performing a third mixing to mix a mixed liquid obtained from the second mixing and an adhesive agent.

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Tokyo, Japan

Narukuni Hirata