Abstract: A method for producing a slurry for a heat-resistant layer for a lithium ion secondary battery, including: a step of producing a polymer aqueous dispersion by polymerizing a monomer in an aqueous medium to give a polymer aqueous dispersion containing a polymer with a polymerization conversion rate of 90 to 100%, a step of obtaining a mixed solution by mixing N-methylpyrrolidone and the polymer aqueous dispersion, a step of obtaining a binder composition by removing an unreacted monomer and the aqueous medium from the mixed solution in a substitution tank, and a step of obtaining a slurry by dispersing non-conductive microparticles in the binder composition, wherein the step of obtaining the binder composition includes removing the aqueous medium and the unreacted monomer, while feeding the mixed solution to an external heating device and feeding a heat quantity to: the mixed solution that has been fed to the external heating device.

Abstract: A method for producing a slurry for a heat-resistant layer for a lithium ion secondary battery, including: a step of producing a polymer aqueous dispersion by polymerizing a monomer in an aqueous medium to give a polymer aqueous dispersion containing a polymer with a polymerization conversion rate of 90 to 100%, a step of obtaining a mixed solution by mixing N-methylpyrrolidone and the polymer aqueous dispersion, a step of obtaining a binder composition by removing an unreacted monomer and the aqueous medium from the mixed solution, and a step of obtaining a slurry by dispersing non-conductive microparticles in the binder composition, wherein the step of obtaining the binder composition includes removing the aqueous medium and the unreacted monomer by using a distillation column under a reduced pressure so that the binder composition contains the unreacted monomer and a water content in predetermined amounts.