Abstract: A polycarbonate resin comprising a structural unit represented by the following formula (1), wherein weight-average molecular weight Mw measured by size-exclusion chromatography using polymethyl methacrylate as a standard sample is 50,000 or larger and 500,000 or smaller:

Abstract: A polyphenylene ether having a predetermined structure.

Abstract: Provided is a method for manufacturing a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. A method for manufacturing a methacrylic resin composition, wherein the methacrylic resin composition comprises two or more types of methacrylic resins that each have a structural unit (X) having the same type of cyclic structure-containing main chain, the methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C., methanol-soluble content is contained in an amount of 5 mass % or less relative to 100 mass %, in total, of the methanol-soluble content and methanol-insoluble content, comprising mixing a low molecular weight component and a high molecular weight component.

Abstract: A polyphenylene ether having a predetermined structure.

Abstract: Provided is a method for manufacturing a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. A method for manufacturing a methacrylic resin composition, wherein the methacrylic resion composition comprises two or more types of methacrylic resins that each have a structural unit (X) having the same type of cyclic structure-containing main chain, the methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C., methanol-soluble content is contained in an amount of 5 mass % or less relative to 100 mass %, in total, of the methanol-soluble content and methanol-insoluble content, comprising mixing a low molecular weight component and a high molecular weight component.

Abstract: Provided is an optical component comprising a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. The optical component contain a methacrylic resin including a structural unit (X) having a cyclic structure-containing main chain that is at least one selected from the group consisting of an N-substituted maleimide monomer-derived structural unit, a glutarimide-based structural unit, and a lactone ring structural unit. The methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C. Among methacrylic acid ester monomer-derived structural units, a ratio (S/H) of the integrated intensity (S) of a syndiotactic fraction (rr) relative to the integrated intensity (H) of a heterotactic fraction (mr), as determined by 1H-NMR measurement, is 1.20 to 1.50. The amount of methanol-soluble content is 5 mass % or less relative to 100 mass %, in total, of methanol-soluble content and methanol-insoluble content.

Abstract: Methacrylic resin having high heat resistance, highly controlled birefringence, excellent color tone and transparency, and excellent moldability is provided. A methacrylic resin comprises a structural unit (B) having a cyclic structure-containing main chain, the structural unit (B) including at least one structural unit selected from the group consisting of an N-substituted maleimide-based structural unit (B-1) and a lactone ring structural unit (B-2), wherein a glass transition temperature is more than 120° C. and 160° C. or less, an amount of a methanol-soluble content is 5 mass % or less relative to 100 mass % of a total amount of the methanol-soluble content and a methanol-insoluble content in the methacrylic resin, and an yellowness index YI measured using a 10 cm optical path length cell for a 20 w/v % chloroform solution of the methanol-insoluble content is 0 to 7.

Abstract: A methacrylic resin composition having high heat resistance, excellent birefringence, and excellent heat stability and molding processability is provided. A methacrylic resin composition comprises: a methacrylic resin including a structural unit (X) having a cyclic structure-containing main chain, the structural unit (X) being at least one type selected from the group consisting of an N-substituted maleimide monomer-derived structural unit, a glutarimide-based structural unit, and a lactone ring structural unit; and an organic phosphorous compound, wherein a glass transition temperature is more than 120° C. and 160° C. or less, a content of a phosphorus element is 10 mass ppm to 1000 mass ppm, and a ratio P3/P5 of an integral value P3 of a spectral peak assigned to trivalent phosphorus to an integral value P5 of a spectral peak assigned to pentavalent phosphorus in 31P-NMR measurement is 0.2 to 5.0.

Abstract: Provided is a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. The methacrylic resin composition and an optical component contain a methacrylic resin including a structural unit (X) having a cyclic structure-containing main chain that is at least one selected from the group consisting of an N-substituted maleimide monomer-derived structural unit, a glutarimide-based structural unit, and a lactone ring structural unit. The methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C. Among methacrylic acid ester monomer-derived structural units, a ratio (S/H) of the integrated intensity (S) of a syndiotactic fraction (rr) relative to the integrated intensity (H) of a heterotactic fraction (mr), as determined by 1H-NMR measurement, is 1.20 to 1.50. The amount of methanol-soluble content is 5 mass % or less relative to 100 mass %, in total, of methanol-soluble content and methanol-insoluble content.

Abstract: There is provided a catalyst composition for polymerizing a conjugated diene monomer containing a rare earth complex having a specific structure and a specific compound.

Abstract: There is provided a catalyst composition for polymerizing a conjugated diene monomer containing a rare earth complex having a specific structure and a specific compound.

Abstract: A seat frame assembly of a motorcycle has upper and lower pipes made of an aluminum alloy and having a rectangular cross-sectional shape. The upper and lower pipes have front ends constructed as joints, and solid spacers made of an aluminum alloy and having a cross-sectional shape substantially identical to the rectangular cross-sectional shape of the pipes are fitted in the joints. Flat side walls of each of the joints are sandwiched between flat electrodes of a resistance welding machine, and pressed and heated so as to be crimped on the spacer while an electric current is flowing between the flat electrodes.

Abstract: A seat frame assembly of a motorcycle has upper and lower pipes made of an aluminum alloy and having a rectangular cross-sectional shape. The upper and lower pipes have front ends constructed as joints, and solid spacers made of an aluminum alloy and having a cross-sectional shape substantially identical to the rectangular cross-sectional shape of the pipes are fitted in the joints. Flat side walls of each of the joints are sandwiched between flat electrodes of a resistance welding machine, and pressed and heated so as to be crimped on the spacer while an electric current is flowing between the flat electrodes.