A PET aversion? Biorenewable monomers take centre stage

Biorenewable monomers are not something this Kat comes across on a daily basis. Accordingly he is not in the best position to address the issue raised by his correspondent Maja Schmitt, who writes:

"The discussion [of the patentability of biorenewable monomers] is very similar to the discussions on gene patenting, and we are afraid that patent offices are not setting out their position on this issue yet. For example:

US 20090246430: a bio-based polyethylene terephthalate [PET] polymer comprising from about 25 to about 75 weight percent of a terephthalate component, wherein the terephthalate component is selected from terephthalic acid, dimethyl terephthalate, isophthalic acid, and a combination thereof, and
from about 20 to about 50 weight percent of a diol component,
wherein the diol component is selected from ethylene glycol, cyclohexane dimethanol,
and a combination thereof,
wherein at least about one weight percent of at least one of the terephthalate and/or the diol component is derived from at least one bio-based material.
dependent claim: wherein the bio-based polyethylene terephthalate polymer comprises at least about 0.1 dpm/gC of carbon-14.

The text of the patent contains the following:

It is known in the art that carbon-14 (C-14), which has a half life of about 5,700 years, is found in bio-based materials but not in fossil fuels. Thus "bio-based materials" refers to organic materials in which the carbon comes from non-fossil biological sources. As explained previously, the detection of C-14 is indicative of a bio-based material. C-14 levels can be determined by measuring its decay process (disintegrations per minute per gram carbon or dpm/gC) through liquid scintillation counting.

Now, assuming that the chemistry in this claim is the same that is already available for making PET (but from fossil derived monomers) then the only difference is the level of C14. At a push you could argue that it is novel -- but how could it ever be inventive, when every teaching out there is about replacing monomers from oil with monomers from plants ?

We have noticed that these types of claims are beginning to be allowed, which means that the only option is to oppose them in order to try and create case law.

Have you in all your blogs come across this issue and seen any case law?"

No, in all truth, says the IPKat. There are times when I feel truly knowledgeable and times when I feel confident enough to float a slightly imaginative answer and see what happens. But here I'm truly out of my depth. Can anyone offer any useful thoughts or comments? Merpel adds, I note that this application is made by the Coca-Cola Company and hope that the patent covers the bottle rather than its contents ...