Kitchen Light Toggle Switch Replaced, Now tripping
What you are describing is a low impact overload. If it is a 15A circuit and if it was pulling say 17A it may take 2 or 3 minutes for the breaker to heat up and trip. Some breakers do go bad basically due to overuse. Do you have an ammeter or could you borrow one to see what the circuit is actually pulling? Without amperage information it would be hard to analyze what could be wrong.