(a) Except as otherwise provided in subdivision (b) and in Sections 9406, 9407, 9408, and 9409, whether a debtor’s rights in collateral may be voluntarily or involuntarily transferred is governed by law other than this division.
(b) An agreement between the debtor and secured party which prohibits a transfer of the debtor’s rights in collateral or makes the transfer a default does not prevent the transfer from taking effect.