Nope, no patents on plastic types by any disc company that I know of.
They all purchase their plastic from distributors. Innova could keep it a secret which exact type of plastic CE was and where it came from, but they definitely do not hold a patent on any plastic blend.
Dave D did have the patent on the triangle-shaped disc rim, which is why you have that same Innova patent number molded onto other companies discs, but it has since expired. They no longer need to license it.
Dave D always seems to makes it sound like the source plastic they get is not in innova's control. I don't know exactly what this means but he has a habit of making CE sound like it was some kind of happy accident and thus can't be recreated. That actually seems like his take on a number of the details of innova's discs.
I don't really understand this as a business practice even if it is true. You might think he would bluff control if he didn't have it, or even just hint at it. Instead he seems to shirk it off. He's either playing coy cause it's easy or maybe just being straight up.