VISCOSITY INDEX IMPROVING AGENT AND LUBRICATING OIL COMPOSITION

    公开(公告)号:US20230312797A1

    公开(公告)日:2023-10-05

    申请号:US18025238

    申请日:2021-09-14

    IPC分类号: C08F279/02 C08K5/101 C08K5/01

    CPC分类号: C08F279/02 C08K5/101 C08K5/01

    摘要: The present invention aims to provide a viscosity-index improving agent capable of providing a lubricating oil composition having an appropriate gelation index, an excellent HTHS viscosity at 100° C., and an excellent kinematic viscosity at 40° C. when the viscosity-index improving agent is added thereto. The present also aims to provide a lubricating oil composition containing the viscosity-index improving agent. The present invention relates to, for example, a viscosity-index improving agent containing a copolymer (A) and an ester oil (Z), the copolymer A containing, as constituent monomers, a polyolefin-based monomer (a) represented by the following formula (1), a monomer (b) represented by the following formula (2) in which R4 is a C4 alkyl group, and at least one of a monomer (c) represented by the following formula (3) and a monomer (d) represented by the following formula (2) in which R4 is a C2-C3 alkyl group:




    wherein R1 is a hydrogen atom or a methyl group; —X1— is a group represented by —O—, —O(AO)m—, or —NH—, A is a C2-C4 alkylene group, m is an integer of 1 to 10, and each A may be the same or different when m is 2 or more; R2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer containing a 1,2-butylene group as a structural unit; and p represents a number of 0 or 1;




    wherein R3 is a hydrogen atom or a methyl group; —X2— is a group represented by —O— or —NH—; and R4 is a C2-C4 alkyl group;




    wherein R5 is a hydrogen atom or a methyl group; —X3— is a group represented by —O— or —NH—; R6 is a C2-C4 alkylene group; R7 is a C1-C8 alkyl group; and r is an integer of 1 to 20, and each R6 may be the same or different when r is 2 or more.