Fraud
england-and-wales northern-ireland
This would be fraud under Section 2 of the Fraud Act 2006:
(1) A person is in breach of this section if he — (a) dishonestly
makes a false representation, and (b) intends, by making the
representation — (i) to make a gain for himself or another, or (ii) to
cause loss to another or to expose another to a risk of loss.
(2) A representation is false if — (a) it is untrue or misleading, and
(b) the person making it knows that it is, or might be, untrue or
misleading.
(3) “Representation” means any representation as to fact or law,
including a representation as to the state of mind of — (a) the person
making the representation, or (b) any other person.
(4) A representation may be express or implied.
When you, as a director, sign the loan application form, you are representing that you will pay the loan back. The fact that you know that you intend to default on the loan makes it a false representation. Limited liability is irrelevant here. See Section 12:
(1) Subsection (2) applies if an offence under this Act is committed
by a body corporate.
(2) If the offence is proved to have been committed with the consent
or connivance of — (a)a director, manager, secretary or other similar
officer of the body corporate, or (b) a person who was purporting to
act in any such capacity, he (as well as the body corporate) is guilty
of the offence and liable to be proceeded against and punished
accordingly.
On a more practical note, banks aren't oblivious to the possibility of the scenario you describe. The chances of a major bank issuing a large loan to a brand new company without also requiring a guarantee from the director is essentially nil. Note that "unsecured" in this context means that no asset is used to secure the loan (e.g. land or a car). It doesn't mean that the director won't be required to provide a guarantee.
Transaction unwinding
england-and-wales
Section 238 of the Insolvency Act 1986 provides as follows:
(1) This section applies in the case of a company where - (a) the company enters administration, (b) the company goes into liquidation; and “the office-holder” means the administrator or the
liquidator, as the case may be.
(2) Where the company has at a relevant time (defined in section 240)
entered into a transaction with any person at an undervalue, the
office-holder may apply to the court for an order under this section.
(3) Subject as follows, the court shall, on such an application, make
such order as it thinks fit for restoring the position to what it
would have been if the company had not entered into that transaction.
(4) For the purposes of this section and section 241, a company enters
into a transaction with a person at an undervalue if - (a) the company
makes a gift to that person or otherwise enters into a transaction
with that person on terms that provide for the company to receive no
consideration, or (b) the company enters into a transaction with that
person for a consideration the value of which, in money or money’s
worth, is significantly less than the value, in money or money’s
worth, of the consideration provided by the company.
This provides creditors with the ability to ask the Court to "unwind" the transaction and recover the money from the director. See Section 240 and 249 for details of the time limits for doing this.