Don’t call it “director’s loan” if you’re a partnership, that’s a specific term related to limited companies.
As a partnership there’s no legal separation between you and the business, so there’s no “liability” as such (you can’t owe money to yourself). Rather, if you’ve used your own funds to provide cash or pay startup costs (like purchasing equipment) then this counts as capital you have introduced to the business.
What my accountant advised for my partnership was to create a set of new nominals under the capital and reserves section for each individual partner to track their capital introduced, drawings taken, and share of the business profits, as well as one drawings “bank account” per partner. If a partner provides a cash lump sum to the business then that would be money in to the current account tagged (via “something not on the list”) to their capital introduced account. If a partner makes a big purchase for the business then the easiest way to handle that is to process the purchase in the normal way, mark it as paid from that partner’s drawings bank account, then balance that with a “money in” tagged to their capital introduced account.
At the end of the year I sweep any remaining balance on each partner’s drawings bank account into their “drawings taken” capital account, and in the year end journal I split the retained profit between the partners’ profit share accounts, so that each partner’s capital introduced plus profit share minus drawings taken gives their capital “share” in the partnership at any given time.