BINDER FOR ALL-SOLID-STATE SECONDARY BATTERIES, BINDER COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERIES, SLURRY FOR ALL-SOLID-STATE SECONDARY BATTERIES, SOLID ELECTROLYTE SHEET FOR ALL-SOLID-STATE SECONDARY BATTERIES AND METHOD FOR PRODUCING SAME, AND ALL-SOLID-STATE SECONDARY BATTERY AND METHOD FOR PRODUCING SAME

Provided are a binder for an all-solid-state secondary battery, which is excellent in adhesiveness and flexibility, has a satisfactory cycle life characteristic, and can achieve a high yield, and a binder composition for an all-solid-state secondary battery containing the binder. The binder for an all-solid-state secondary battery according to the present invention includes a conjugated diene-based copolymer (A) that: has an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound; and has a storage elastic modulus (G') of 4.0×104 Pa or more and 2.0×105 Pa or less and a loss tangent (tan6) of 0.10 or more and 0.80 or less, which are measured using a dynamic viscoelasticity-measuring apparatus under conditions of a measurement temperature of 25°C, a frequency of 0.1 Hz, and a strain amount of 1%.