초록 ▼

This invention is based upon the discovery that rubbery polymers having a high vinyl content and a low degree of branching can be synthesized with an initiator system that is comprised of (a) a lithium initiator selected from the group consisting of allylic lithium compounds and benzylic lithium com

This invention is based upon the discovery that rubbery polymers having a high vinyl content and a low degree of branching can be synthesized with an initiator system that is comprised of (a) a lithium initiator selected from the group consisting of allylic lithium compounds and benzylic lithium compounds, (b) a Group I metal alkoxide, and (c) a polar modifier; wherein the molar ratio of the Group I metal alkoxide to the polar modifier is within the range of about 0.1:1 to about 10:1; and wherein the molar ratio of the Group I metal alkoxide to the lithium initiator is within the range of about 0.01:1 to about 20:1. These high vinyl polymers offer reduced levels of hysteresis and better functionalization efficiency. By virtue of their lower level of hysteresis these polymers can be utilized in manufacturing tire tread compounds that exhibit lower levels of rolling resistance and can accordingly be used to improve the fuel economy of motor vehicles without compromising other desirable characteristics, such as traction and tread-wear.

대표청구항 ▼

This invention is based upon the discovery that rubbery polymers having a high vinyl content and a low degree of branching can be synthesized with an initiator system that is comprised of (a) a lithium initiator selected from the group consisting of allylic lithium compounds and benzylic lithium com

This invention is based upon the discovery that rubbery polymers having a high vinyl content and a low degree of branching can be synthesized with an initiator system that is comprised of (a) a lithium initiator selected from the group consisting of allylic lithium compounds and benzylic lithium compounds, (b) a Group I metal alkoxide, and (c) a polar modifier; wherein the molar ratio of the Group I metal alkoxide to the polar modifier is within the range of about 0.1:1 to about 10:1; and wherein the molar ratio of the Group I metal alkoxide to the lithium initiator is within the range of about 0.01:1 to about 20:1. These high vinyl polymers offer reduced levels of hysteresis and better functionalization efficiency. By virtue of their lower level of hysteresis these polymers can be utilized in manufacturing tire tread compounds that exhibit lower levels of rolling resistance and can accordingly be used to improve the fuel economy of motor vehicles without compromising other desirable characteristics, such as traction and tread-wear. 13, (2000). Kalra and Gross; Enzymatic Synthesis of Predominantly Syndiotactic Poly(Methyl Methacrylate), Book of Abstracts, 219thACS National Meeting, San Francisco, CA , Mar. 26-30, 2000. Kitayama et al.; "Highly Syndiotactic Poly(methyl methacrylate). With narrow molecular weight distribution formed by tert-butyllithium-trialkylaluminium in Toluene", Polymer Bulletin, 20 pp. 505-510 (1988). Lalot et al.; " A Kinetic Approach to Acrylamide Radical Polymerization by Horse Radish Peroxidase-mediated Initiation ", Polymer Int. 48: 288-292 (1999). Uyama et al.; " Chemoselective Polymerization of a Phenol Derivative Having a Methacryl Group by Peroxidase Catalyst", Macromolecules, 31 (2): 554-556 (1998). Teixeira et al.; " β-Diketones as Key Compounds in Free-Radical Polymerization by Enzyme-Mediated Initiation".