S.C. Code Ann. § 36-9-315
(a) Except as otherwise provided in this article and in Section 36-2-403(2):
(b) Proceeds that are commingled with other property are identifiable proceeds:
(d) A perfected security interest in proceeds becomes unperfected on the twenty-first day after the security interest attaches to the proceeds unless:
(1) the following conditions are satisfied:
(e) If a filed financing statement covers the original collateral, a security interest in proceeds which remains perfected under subsection (d)(1) becomes unperfected at the later of: