Provided are a rubber composition which provides a self-healing rubber with improved strength and wet grip performance, and a pneumatic tire including the rubber composition. The present disclosure relates to a rubber composition containing a rubber component having a functional group containing a cationic functional group and/or an anionic functional group, a filler capable of generating a charge paired with the functional group, and sulfur.

An acrylic rubber composition containing: an acrylic rubber containing 100 parts by mass of an alkyl acrylate and 30 to 60 parts by mass of an alkyl methacrylate, as monomer units; a carbon black; a crosslinking agent; and a crosslinking accelerator.

An acrylic rubber composition containing: an acrylic rubber containing 100 parts by mass of an alkyl acrylate and 30 to 60 parts by mass of an alkyl methacrylate, as monomer units; a carbon black; a crosslinking agent; and a crosslinking accelerator.

A rubber composition includes a carboxyl group-containing nitrile rubber of which iodine value is 120 or less, a polyetherester plasticizer, and a metallic compound, wherein an amount of stearic acid adsorbed by the metallic compound is 80 mg/g or more and 300 mg/g or less.

A rubber composition includes a carboxyl group-containing nitrile rubber of which iodine value is 120 or less, a polyetherester plasticizer, and a metallic compound, wherein an amount of stearic acid adsorbed by the metallic compound is 80 mg/g or more and 300 mg/g or less.

A rubber composition includes a carboxyl group-containing nitrile rubber of which iodine value is 120 or less, a polyetherester plasticizer, and a metallic compound, wherein an amount of stearic acid adsorbed by the metallic compound is 80 mg/g or more and 300 mg/g or less.

A sealing member includes a sliding portion made of a vulcanized rubber composition. The rubber composition includes a carboxyl-containing acrylic rubber, a silica, and a glass fiber. A content of the silica is 25 to 100 parts by weight per 100 parts by weight of the carboxyl-containing acrylic rubber.

A sealing member includes a sliding portion made of a vulcanized rubber composition. The rubber composition includes a carboxyl-containing acrylic rubber, a silica, and a glass fiber. A content of the silica is 25 to 100 parts by weight per 100 parts by weight of the carboxyl-containing acrylic rubber.

A sealing member includes a sliding portion made of a vulcanized rubber composition. The rubber composition includes a carboxyl-containing acrylic rubber, a silica, and a glass fiber. A content of the silica is 25 to 100 parts by weight per 100 parts by weight of the carboxyl-containing acrylic rubber.

Provided is a paste for a secondary battery that can cause an electrode mixed material layer to display excellent adhesiveness and can reduce internal resistance of a secondary battery. The paste for a secondary battery contains a conductive additive, a polymer, and a dispersion medium. The conductive additive includes one or more carbon nanotubes having a surface acid content of not less than 0.01 mmol/g and not more than 0.15 mmol/g, a surface base content of not less than 0.005 mmol/g and not more than 0.500 mmol/g, a ratio of the surface acid content relative to the surface base content of not less than 1.3 and not more than 3.0, and a specific surface area of 150 m.sup.2/g or more.