Conover v. Koch

93 F.2d 917, 25 C.C.P.A. 813, 1938 CCPA LEXIS 34
CourtCourt of Customs and Patent Appeals
DecidedJanuary 24, 1938
DocketNo. 3860
StatusPublished

This text of 93 F.2d 917 (Conover v. Koch) is published on Counsel Stack Legal Research, covering Court of Customs and Patent Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Conover v. Koch, 93 F.2d 917, 25 C.C.P.A. 813, 1938 CCPA LEXIS 34 (ccpa 1938).

Opinion

GaeRett, Presiding Judge,

delivered the opinion of tlie court:

This is an appeal from a decision of the Board of Appeals of the United States Patent Office in an interference proceeding affirming .the decision of the Examiner of Interferences awarding priority to the party Koch upon a single count which reads:

1. Tlie process for the production of pure benzoic acid which comprises treating crude benzoic acid obtained from phthalic anhydride with a small .amount of water which is sufficient to dissolve any phthalic acid and phthalic ■anhydride present, thereby hydrating the phthalic anhydride, and separating the solution from the benzoic acid.

Before us there was no appearance for appellee, nor was any brief filed in his behalf.

The interference was declared between an application of the party Koch, filed February 25, 1929, and an application of the party •Conover, filed June 16, 1930. Koch took no testimony and is restricted to his filing date for conception and reduction to practice. Upon Conover rests the burden of establishing conception and reduction to practice prior to Koch’s filing date, or prior conception, ■coupled with diligence, from just prior to the date upon which Koch filed.

Originally two counts were involved in the interference and, as to both Conover moved to dissolve on the ground that the disclosure ■of Koch did not support them. The motion was sustained by the Examiner of Interferences as to count 2, but denied as to count 1, the count in issue. There was no appeal by the party Koch, and the party Conover porceeded to take testimony for the purpose of showing reduction to practice by him of count 1 prior to the filing date of Koch in whose application the count originated.

It will be observed that the count requires the treatment of “crude benzoic acid obtained from phthalic anhydride with a small amount [815]*815-of toat&r * * * sufficient to dissolve any phthalic acid and phthalic anhydride present. * * *” with the result that the phthalic anhydride is hydrated and the solution is separated from the '.benzoic acid. [Italics ours.] The phrase “a small amount of water” ■does not appear in either specification but did appear in the original ■claim of the Koch application. Obviously, standing alone, the phrase is indefinite. It is, perhaps, clarified somewhat by the clause which follows “* * * sufficient to disssolve any phthalic acid and phthalic anhydride present.” For the actual amounts of water whose use is taught we are remitted to the examples given in the specification of Koch and to the evidence relative to Conover’s reduction to practice.

It appears that benzoic acid is manufactured from phthalic anhy-■dried. It is said in the brief for Conover that two processes for its manufacture are known, one being by a vapor phase process and one by a liquid phase process. Conover holds patents for both processes, as is evidenced by three patents-filed as exhibits to Conover’s testimony, two- of them covering separate features of the so-called liquid phase in which steam is bubbled through molten phthalic anhydride ■containing a catalyst. The steam reacts with the molten anhydride and forms benzoic acid, but the transformation is not complete under all conditions and, as a result, there must be purification to remove the unreacted phthalic anhydride. The invention at issue relates to the last named step.

The following statement is made in the brief for Conover and appears to be based upon Conover’s specification:

One step in the process of removing the phthalic anhydride consists in hydrolyzing the anhydride with water to form phthalic acid. In the second step the phthalic acid is dissolved by the addition of more water. Thus, it is to he noted that water serves two functions:
1. To hydrate the phthalic anhydride to form phthalic acid.
2. To dissolve the phthalic acid.

The brief then adds:

The amount of water required for the first function is small compared to the amount of water required for the second function. A great deal of water for one function might easily he an insufficient quantity for the second function. * * *.

While we have no reason to question the accuracy of this last statement, it is not found specifically set forth in the specification.

The specification of Koch recites:

According to my present invention the purification of the crude benzoic acid is effected by treating it with a reducing agent, converting any phthalic an-hydride present into a readily soluble compound, such as phthalic acid or readily soluble salts, and removing the impurities by leaching with water or aqueous solutions. By the said treatment with a reducing agent any naphtho-[816]*816quillones that may be present in the crude benzoic acid, are converted into readily soluble naphthohydroquinones.
The process according to my invention may be carried out by making the crude benzoic acid, which has previously been brought into a state as finely divided as possible, so that its particles have a diameter of, for example, 0.01 to 0.02 millimeter, into a xiaste with water and treating that paste while stirring with sodium bisulphite or gaseous sulphur dioxide; thereby the naphtho-quinones are converted into the corresponding naphthohydroquinones and any phthalic anhydride present is converted into phthalic acid. By filtering the mass by suction, the aqueous solution which contains the impurities is removed, and practically pure benzoic acid is left on the filter. If necessary, the said operation may be repeatedly applied.
* * * In case the crude benzoic acid is free from naphthoquinone, the treatment with a reducing agent may even be dispensed with. * * *

It will be observed from the foregoing that, except in cases where naphthoquinone is absent from the crude benzoic acid, Koch teaches the use of a reducing agent, sodium bisulphate or gaseous sulphur dioxide being named as such. Sodium carbonate is also named in the Koch specification.

The Conover specification recites that “It is advantageous to add a small quantity of a basic material such as sodium carbonate to the crude benzoic acid.”

The count makes no mention of a reducing agent.

Koch gives a number of examples illustrating the ingredients and proportions thereof used by him. It is noted that in the examples so given he mentions the use of a reducing agent, such as sodium sul-phite and sodium bicarbonate. In three of the examples here pertinent the proportions of water to crude benzoic acid is that of 3 parts water and 1 part acid; in a fourth example the proportion is that of 2 parts water to 1 part acid. No example is given of the proportions of water and acid when no reducing agent is shown.

In the Conover specification it is recited, in substance, that he distills benzoic acid with steam, and that he thus obtains a “’condensate consisting essentially of equal amounts by weight of water and benzoic acid.” This, as we understand it, is the step of hydrolyzing the'anhydride with water, and it is foliowed by dissolving the phthalic acid by adding more water.

Free access — add to your briefcase to read the full text and ask questions with AI

Cite This Page — Counsel Stack

Bluebook (online)
93 F.2d 917, 25 C.C.P.A. 813, 1938 CCPA LEXIS 34, Counsel Stack Legal Research, https://law.counselstack.com/opinion/conover-v-koch-ccpa-1938.