I am curious as to patentability of one critical parameter of an existing (and patented) process. For clarity I will posit a hypothetical situation analogous to a real situation.

Industrial material A has the possibility of being made at better performance via new process class B. So over the years various inventors develop variants of B, i.e. B1, B2, B3 . . .

All class B processes focus the process on a single idea, e.g. that chilling of the material from its production temperature to ambient conditions will produce a material with superior properties. This is generally observed by all researchers and industrial producers. The various different class B processes differ only in how this chilling is done. Most of the class B processes were invented by engineers rather than pure scientists (i.e. chemists, physicists, biologists) in those industries producing material A.

A new researcher X who has a pure science background, after looking in detail through decades of research data of class B type processes and being cognizant of the physical and chemical state of the starting material, realizes that rapid heat extraction via chilling is not the sole factor involved in this transformation. For example, X may intelligently speculate that the chill starting temperature is also very important as it affects the condition of the primary state of the material and therefore its subsequent evolution during chilling. X supports this hypothesis with extraneous but largely uncommented-on data from prior publications on B processes. X also does his/her own experiments that clearly show situations where a moderate chill from a temperature higher than that used in normal production can produce even better material than that made via a severe chill from the normal production temperature.

The results in terms of material performance are dramatic. Yet the only real difference in processing practice is that X has adjusted one parameter for all class B processes with his/her insight: something that was definitely not obvious to many good engineers working in that area. There is no doubt that X's contribution will have industrial application and will surely lead to much higher performance in material A with appropriate added value to its unit cost. And it is almost certainly "new" to the world as the social/financial incentives for its publication/patenting by any prior discoverer would have been substantial.

But given that it essentially only requires an adjustment of a single process parameter to each of a class of existingly patented processes, can it be regarded as patentable ?

I would be very interested in the opinions of patent agents/attorneys on this question.

  • 1
    Could you please edit your second paragraph? I’m having trouble comprehending it.
    – Eric S
    Commented Feb 21, 2021 at 16:11
  • @Eric S : Editing now done - thanks for pointing out the problem.
    – Trunk
    Commented Feb 21, 2021 at 16:57

1 Answer 1


As you describe it, this would be a patentable invention. A surprising critical range that makes a unsuspected huge difference is classic. However it is complicated by principles like

"where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation," citing In re Aller, 220 F.2d 454, 456 (CCPA 1955); In re Geisler, 116 F.3d 1465, 1469–70 (Fed. Cir. 1997); and In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990)."]1

Patentablity is improved if the performance was not recognized as being sensitive to the exact value of the parameter. And you are in great shape if there was literature "teaching away". Everybody thinks colder is better and you find out warmer is better. Also if there are dozens of parameters that might affect performance you might avoid the deadly "obvious to try" obviousness argument.

The owner of a resulting patent would still need to license the existing patent for the process since you are performing all of the steps of that older patent.

  • Thanks for response, GW. So X may have an arguable case if there was little discussion of the potentially exploitable effects of the other critical parameter in the context of processes of class B applied to materials like A although the same principle may have been utilized in other industries, e.g. pharmaceutical or cosmetics industries ? The optimization dictated from consideration of the other parameter runs counter to the logic of maximizing chilling and also to the bias resulting from the research thrust of all others directly active in that field.
    – Trunk
    Commented Feb 21, 2021 at 21:57
  • Yes, and another indica is so-called "long felt need". Everyone knew about the process and it was being periodically improved. Lots of people playing with it and lots of people wishing it worked better but know one hit on this. Knowledge from other fields can be brought in in obviousness arguments by arguing that analogous problems was being solved.
    – George White
    Commented Feb 21, 2021 at 22:33
  • Knowledge from other fields can be brought in in obviousness arguments by arguing that analogous problems was being solved. . . . So the opponents of a patent application may use this against X ? I would not say obviousness in relation to the described innovation but I would allow obtainability for researchers genuinely scientific (knowledge seeking) rather than engineering (performance/cost) in their approach. And as you know, what's an obvious solution after it's presented is seldom obvious when only shown the problem it solves.
    – Trunk
    Commented Feb 22, 2021 at 11:54
  • @Trunk Are you saying that they system does or should treat patentablity differently if the work was performed by an engineer or a scientist?
    – George White
    Commented Feb 22, 2021 at 20:07
  • Of course not. It's not a system if it discriminates based on anything other than patentability. What I'm saying is that a pure scientist (esp. a chemist) forced to work in the industry in question above is more likely than an engineer to catch on to innovations like that described above. Their mindset is more attuned to phenomena, rather than the exploitation of phenomena. Yet I know of large producers employing pure sciences researchers that can overlook this sort of improvement. Human and socio-professional factors are also at play in group research: they has pros and cons.
    – Trunk
    Commented Feb 23, 2021 at 0:06

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