3. How New Debtor Becomes Bound. Normally, a security interest is unenforceable unless the debtor has authenticated a security agreement describing the collateral. See Section 9- 203(b) [Maine cite section 9-1203, subsection (2)]. New Section 9-203(e) [Maine cite section 9-1203, subsection (5)] creates an exception, under which a security agreement entered into by one person is effective with respect to the property of another. This exception comes into play if a "new debtor" becomes bound as debtor by a security agreement entered into by another person (the "original debtor"). (The quoted terms are defined in Section 9-102 [Maine cite section 9-1102].) If a new debtor does become bound, then the security agreement entered into by the original debtor satisfies the security-agreement requirement of Section 9-203(b)(3) [Maine cite section 9-1203, subsection (2), paragraph (c)] as to existing or after-acquired property of the new debtor to the extent the property is described in the security agreement. In that case, no other agreement is necessary to make a security interest enforceable in that property. See Section 9-203(e) [Maine cite section 9-1203, subsection (5)].

Section 9-203(d) [Maine cite section 9-1203, subsection (4)] explains when a new debtor becomes bound by an original debtor's security agreement. Under Section 9-203(d)(1) [Maine cite section 9-1203, subsection (4), paragraph (a)], a new debtor becomes bound as debtor if, by contract or operation of other law, the security agreement becomes effective to create a security interest in the new debtor's property. For example, if the applicable corporate law of mergers provides that when A Corp merges into B Corp, B Corp becomes a debtor under A Corp's security agreement, then B Corp would become bound as debtor following such a merger. Similarly, B Corp would become bound as debtor if B Corp contractually assumes A's obligations under the security agreement.

Under certain circumstances, a new debtor becomes bound for purposes of this Article even though it would not be bound under other law. Under Section 9-203(d)(2) [Maine cite section 9-1203, subsection (4), paragraph (b)], a new debtor becomes bound when, by contract or operation of other law, it (i) becomes obligated not only for the secured obligation but also generally for the obligations of the original debtor and (ii) acquires or succeeds to substantially all the assets of the original debtor. For