Abstract: Provided is a bump stopper which is unlikely to buckle. The bump stopper is provided with a cylindrical main body made of polyurethane foam. The main body has a first groove formed in the outer peripheral surface thereof, the first groove being recessed radially inward and extending circumferentially. A ring member, which is harder than polyurethane foam, is mounted in the first groove to be retained on the outer circumferential surface of the main body. The overall axial length L1 of the main body is 66 mm or longer. When an axial distance L2 from a back end of the main body to a surface of the ring member located on the back end side is divided by an axial distance L3 from the front end of the main body to a surface of the ring member located on the front end side, L2/L3 satisfies 3?L2/L3?4.2.

Abstract: The present invention provides an optically active poly(diphenylacetylene) compound represented by the following formula (I): [wherein each symbol is as described in the DESCRIPTION], and a production method thereof, an optical isomer separating agent containing the poly(diphenylacetylene) compound, and a packing material for a chiral column, containing the optical isomer separating agent coated on a carrier. According to the present invention, a practical optical isomer separation agent having a high optical resolution ability for a wide variety of racemic compounds and an optical isomer separation method can be provided.

Abstract: The present invention provides an optical isomer separating agent and a production method thereof. That is, the present invention provides a one-handed helical poly(diphenylacetylene) compound represented by the following formula (I) [wherein each symbol is as described in the DESCRIPTION], and a production method thereof, an optical isomer separating agent containing the poly(diphenylacetylene) compound, and a packing material for a chiral column, containing the optical isomer separating agent coated on a carrier. Since these have a superior separation ability for a wide variety of compounds, a practical optical resolution method can be provided.

Abstract: The present invention provides an optical isomer separating agent and a production method thereof. That is, the present invention provides a one-handed helical poly(diphenylacetylene) compound represented by the following formula (I) [wherein each symbol is as described in the DESCRIPTION], and a production method thereof, an optical isomer separating agent containing the poly(diphenylacetylene) compound, and a packing material for a chiral column, containing the optical isomer separating agent coated on a carrier. Since these have a superior separation ability for a wide variety of compounds, a practical optical resolution method can be provided.

Abstract: The present invention provides an optically active poly(diphenylacetylene) compound represented by the following formula (I): [wherein each symbol is as described in the DESCRIPTION], and a production method thereof, an optical isomer separating agent containing the poly(diphenylacetylene) compound, and a packing material for a chiral column, containing the optical isomer separating agent coated on a carrier. According to the present invention, a practical optical isomer separation agent having a high optical resolution ability for a wide variety of racemic compounds and an optical isomer separation method can be provided.