BINDER COMPOSITION FOR SECONDARY BATTERY POSITIVE ELECTRODE, SLURRY COMPOSITION FOR SECONDARY BATTERY POSITIVE ELECTRODE AND METHOD OF PRODUCING SAME, POSITIVE ELECTRODE FOR SECONDARY BATTERY, AND SECONDARY BATTERY

A binder composition for a secondary battery positive electrode contains a polymer including a nitrile group-containing monomer unit, an aromatic vinyl monomer unit, a hydrophilic group-containing monomer unit, a conjugated diene monomer unit, and a linear alkylene structural unit having a carbon number of 4 or more. The aromatic vinyl monomer unit is included in the polymer in a proportion of not less than 30.0 mass % and not more than 60.0 mass %. The polymer has an iodine value of not less than 60 mg/100 mg and not more than 150 mg/100 mg.