Chuffing,
A bank would only go to 50% normally of a business bank loan and for that size they would certainly want some security. Business Angels may be an option depending on the type of business it is - if it is going to make some serious money then they may invest as they want a quick return on their money. If there isnt the option for a serious return on their investment then they will probably not look to invest. Invest some time on writing a thorough business plan and then look at it in the cold light of day.