Binder composition for all-solid-state secondary battery

A solid electrolyte layer for an all-solid-state secondary battery formed using a slurry composition for an all-solid-state secondary battery solid electrolyte layer comprising a binder composition for an all-solid-state secondary battery;

• and a solid electrolyte,
• wherein the binder composition for an all-solid-state secondary battery comprises a polymer, an anti-aging agent, and an organic solvent,
• wherein the polymer includes a (meth)acrylic acid ester monomer unit in a proportion of not less than 25 mass % and not more than 95 mass % and a hydrophobic monomer unit, and has a gel content of 50 mass % or less, and
• wherein the anti-aging agent is contained in an amount of not less than 0.005 parts by mass and not more than 0.5 parts by mass per 100 parts by mass of the polymer.