BINDER COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERY, SLURRY COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERY ELECTRODE MIXED MATERIAL LAYER, SLURRY COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERY SOLID ELECTROLYTE LAYER, AND ALL-SOLID-STATE SECONDARY BATTERY

Provided is a binder composition for an all-solid-state secondary battery with which it is possible to form a solid electrolyte-containing layer that can cause an all-solid-state secondary battery to display excellent output characteristics and high-temperature cycle characteristics. The binder composition contains a polymer A that includes a nitrile group-containing monomer unit and an aliphatic conjugated diene monomer unit. The proportional content of the nitrile group-containing monomer unit in the polymer A is not less than 5 mass % and not more than 30 mass %, and the proportional content of the aliphatic conjugated diene monomer unit in the polymer A is not less than 40 mass % and not more than 95 mass %. The polymer A has a Mooney viscosity (ML, 100° C.) of 65 or more.