It is not clear what kind of relationship you have with your business partner. It seems you are not a (co-)owner of the company, but does that mean that you are

It is not clear what kind of relationship you have with your business partner. It seems you are not a (co-)owner of the company, but does that mean that you are an employee. If you have the legal status of an employee, I guess you might not have any right on part of the sale. But maybe you have some right for a compensation if you become unemployed as a result of the sale.