Question to the mentioned topic if Kodak ceased all production and kept their formulas "secret"

1. Are the formulas protected by patent?

2. Isn't one of the requirements for patent protection that the patent be used? That is you can not be awarded a patent and just sit on it......

3. It shouldn't be that difficult for formulas to be duplicated?

4. Would it be cost effective and would other companies step up to the plate even if the most popular formulas were available....