primer for problem areas on concrete?

I've got a 500 sq ft concrete floor that was painted around a 1 1/2 years ago in Ronseal Diamond Hard floor paint (I know, acrylic, but epoxy wasn't available locally & wasn't given the time for solvent to dry....). The paint has worn far better than expected, but I've got a few small problem areas;

* A couple of small patches that the paint didn't adhere well to in the first place - looks like adhesive or chemicals may have previously been spilt here.

* Small area in a toilet that didn't adhere well (area was dry)

* A high wear area where the paint has lifted prematurely.


(The floor was previously painted in solvent floor paint (a long time ago), was thoroughly sanded removing the majority of the old paint, cleaned, degreased & allowed to dry properly before it was painted)

I'm thinking that to resolve the bad spots I should clean the areas with concrete cleaner & then use a primer / isolator product before repainting - any ideas on what product may be best for this?

Thanks.