Active material for negative electrodes of nonaqueous secondary batteries, and nonaqueous secondary battery

A method for producing an active material for negative electrodes of nonaqueous secondary batteries;

• the method comprising performing calcination of a composite resin (A), wherein composite resin (A) comprises a silanol group and/or a hydrolysable silyl group and comprises a polysiloxane segment (a1) and a polymer segment (a2) other than the polysiloxane segment (a1),
• the polysiloxane segment (a1) is a polysiloxane segment comprising a structural unit represented by the following general formula (S-2) and/or the following general formula (S-3)
• in the general formulas (S-2) and (S-3), R3, R4, and R5 each independently represent an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group, or an aralkyl group having 7 to 12 carbon atoms, and
• the composite resin (A) comprises a structure represented by the following structural formula (S-5)
• in the structural formula (S-5), the carbon atom is a carbon atom forming the polymer segment (a2), and the two silicon atoms are silicon atoms forming the polysiloxane segment (a1), and the polymer segment (a2) is a vinyl polymer segment of an acrylic polymer.