Case Name: Application of Alois M. GEMASSMER
Court: United States Court of Customs and Patent Appeals
Jurisdiction: United States
Decision Date: 1963-06-28
Citations: 319 F.2d 541
Docket Number: Patent Appeal No. 6945
Parties: Application of Alois M. GEMASSMER.
Judges: Before RICH, Acting Chief Judge, and MARTIN, SMITH, and ALMOND, Judges.
Reporter: Federal Reporter 2d Series
Volume: 319
Pages: 541–547

Head Matter:
50 CCPA
Application of Alois M. GEMASSMER.
Patent Appeal No. 6945.
United States Court of Customs and Patent Appeals.
June 28, 1963.
Clelle W. Upchurch, Pittsburgh, Pa. (John II. Sutherland, St. Louis, Mo., of counsel), for appellant.
Clarence W. Moore, Washington, D. C. (Joseph Schimmel, Washington, D. C., of counsel), for Commissioner of Patents.
Before RICH, Acting Chief Judge, and MARTIN, SMITH, and ALMOND, Judges.

Opinion:
MARTIN, Judge.
This appeal is from a decision of the Board of Appeals affirming the examiner's rejection of claims 10-20 for PREPARATION OF ORGANIC ISOCYA-NATES. Fifteen claims have been allowed.
Claim 10, representative of the appealed claims, reads:
"10. In a method of preparing aromatic isocyanates by reacting, in an inert organic solvent, a stoichiometric excess of phosgene with a compound selected from the group consisting of aromatic primary mono-, di-, and polyamines having no substituents other than primary amino which are capable of reacting with phosgene under the conditions employed, to form the corresponding isocyanate, the improvement which comprises carrying out the initial phosgenation at a temperature within the range of 60°C. to 80°C. to produce an intermediate product, which contains an admixture of the desired isocyanate and the corresponding intermediate carbamyl chloride, and reacting said intermediate product in the presence of phosgene at a higher temperature to produce the aromatic isocyanate."
Appellant's application describes an improved process for the preparation of an organic isocyanate. As pointed out in appellant's specification, it is known in the art that an organic isocyanate can be prepared by reacting phosgene and an amine in two steps:
(1) a primary or cold phosgenation step in which an amine is mixed and reacted with phosgene to form carbamyl chloride and an amine hydrochloride, the temperature of the reaction medium being maintained at a point not above 60°C. in order to limit the amount of undesirable by-products.
(2) a second or hot phosgenation step wherein the reaction mixture from the primary phosgenation step is heated to a temperature of from about 100°C. to about 200°C. while introducing additional phosgene to convert the "carbamyl chloride and amine hydrochloride" into an organic isocyanate.
In the foregoing process, to insure the low temperature in the primary phosgenation step, it is necessary to mix the amine and phosgene together at a relatively slow rate and to furnish external refrigeration. Because of the relatively low temperature however, the chemical reaction in the primary phosgenation step is relatively slow so that the primary phosgenation step takes as much as one hour or more. An object of appellant's invention is to provide a method for making an organic isocyanate which is devoid of the disadvantages inherent in the above primary phosgenation step. Another object is to provide a method for making an organic isocyanate from an amine and phosgene without a prolonged primary phosgenation step and without the need of refrigerating the reaction medium during the primary phosgenation step. A further object is to provide a method for making an organic isocyanate which is adaptable for a greater throughput and greater yield per unit of time with equipment of a given size. Appellant points out in his specification that the foregoing objects and others are accomplished in accordance with his invention, generally speaking, "by providing a process in which an amine, either in solution or suspension in an inert solvent, is contacted with phosgene in a high speed mixer." Appellant finds it unnecessary to cool the reaction medium in the primary phosgenation step since he finds that any temperature not substantially above 80 °C. can be tolerated when a high speed mixer is used.
The examiner's sole ground of rejection is that appellant does not have proper support in his specification for a process of reacting an amine and phosgene to form an isocyanate which process is carried out in the absence of a high speed mixer and, therefore, that the appealed claims are too broad in the lack of a recitation of a provision for high speed mixing in the initial or primary phosgenation step.
Appellant contends that the appealed claims are not too broad and urges that those claims have adequate support in his specification.
The board in sustaining the examiner's rejection stated:
"Appealed claims 10 to 20 are not limited as required by appellant's disclosure in the foregoing respect [operation of the reaction in the initial phosgenation step in a high speed mixer] and we must therefore agree with the Examiner that these appealed claims are too broad and unsupported."
After a careful analysis of appellant's application we are convinced that there is no reversible error in that position of the board.
Appellant wishes to provide a method for making an organic isocyanate from an amine and phosgene without a prolonged primary phosgenation step and without the necessity of refrigerating the reaction mixture in the primary phosgenation. Appellant teaches that this is accomplished, generally speaking,
"by providing a process in which an amine, either in solution or suspension in an inert solvent, is contacted with phosgene in a high speed mixer." [Emphasis ours.]
Appellant finds it unnecessary to cool the reaction mixture in the primary phosgenation step because:
"temperatures of above 60°G. do not adversely affect the yield when mixing is effected in a high speed mixer." [Emphasis ours.]
As for the type of high speed mixer appellant points out in the specification that:
"Any suitable high speed mixer is contemplated by the invention, such as, for example, turbo mixers, colloid mills, pumps including centrifugal pumps, and the like, which contain structural elements which rotate at high speeds and thus insure intimate contact betiveen the amdne and phosgene within a relative short period of time. Preferably, the high speed mixer should be one which rotates at a speed of about 1000 rpm or more. In any event, intimate mixing must be achieved in not substantially more than one minute. The residence time in a high speed mixer must be relatively short and, generally, it is preferred that the reactants not remain in the mixer for substantially more than one minute." [Emphasis ours.]
Each of appellant's examples include the use of a turbo mixer, colloid mill or centrifugal pump in the primary phosgenation step and it is evident, from the above quotation, that appellant uses the turbo mixer, colloid mill or centrifugal pump as a high speed mixer.
From our consideration of appellant's entire specification, it is apparent that it adequately defines, at least, what ap pellant intended in using the term "high speed mixer." Moreover, from our analysis of appellant's entire disclosure, we are convinced that he regarded his invention as requiring that the primary or initial phosgenation step be carried out in a high speed mixer which provides the intimate mixing of the amine and phosgene in not substantially more than one minute.
Appellant emphasizes that his specification includes the following statement:
"Depending upon the speed of the mixer, the reactants may be fed to the mixer continuously at any rate desired."
However, that statement must be considered in connection with the remaining language of the paragraph in which it appears:
"In one embodiment of the process provided by this invention, a solution of phosgene and a solution of an amine are introduced through separate conduits into a high speed mixer. The reactants remain in this mixer for only a few seconds and are fed to a suitable vessel where the reaction mixture is heated to a temperature of about 100°C. or more and phosgene is added to convert the carbamyl chloride into an isocyanate. Depending upon the speed of the mixer, the reactants may be fed to the mixer continuously at any rate desired. Likewise, the rate of flow of reaction mixture into the apparatus wherein the hot phosgenation is conducted may be varied widely without adversely affecting the yield. The temperature of the reactor used for the hot phosgenation may be maintained at the desired reaction temperature from the very outset which makes it possible to carry out the hot phosgenation continuously." [Emphasis ours.]
When the statement is so considered, it is apparent that the term "mixer" in that statement relates back to the term "a high speed mixer" appearing earlier in the paragraph. We are unable to find any basis for regarding the statement in question as disclosing any such speed variation in the primary phosgenation step as would result in anything but high speed mixing which is achieved in not substantially more than one minute.
It seems to us that the use of a high speed mixer (high speed in contrast to time of prior art mixing) being disclosed by appellant as essential to achieve his invention, is a critical limitation of his process. We therefore do not consider that the appealed claims, in the absence of language defining this limitation, point out appellant's invention nor do they have proper support in his specification.
The decision of the board is affirmed.
Affirmed.
WORLEY, C. J., not present at argument, participated by agreement of counsel in this decision.
. Ser. No. 765,298 filed October 6, 1958.
. Those claims have been copied, in modified form, for interference purposes, from U.S. 2,908,703, issued October 13, 1959 to Harold K. Latourette and Oscar H. Johnson, on application Ser. No. 528,846 filed October 16, 1955.