Application of Allen

• Decision Date: 12 December 1963
• Docket Number: Patent Appeal No. 7016.
• Citation: 51 CCPA 809,324 F.2d 993
• Court: U.S. Court of Customs and Patent Appeals (CCPA)
• Parties: Application of Lyman S. ALLEN.

51 CCPA 809, 324 F.2d 993 (1963)

Application of Lyman S. ALLEN.

Patent Appeal No. 7016.

United States Court of Customs and Patent Appeals.

December 12, 1963.

Ellsworth H. Mosher, Stevens, Davis, Miller & Mosher, Washington, D. C., Richard W. Sternberg, St. Louis, Mo., for appellant.

Clarence W. Moore, Washington, D. C. (Jack E. Armore, Washington, D. C., of counsel), for Commissioner of Patents.

Before WORLEY, Chief Judge, and RICH, MARTIN, SMITH and ALMOND, Judges.

SMITH, Judge.

The issue in the present appeal requires a determination of whether the differences between the cited prior art and the invention disclosed in appellant's application¹ and claimed in rejected claims 1-19, inclusive, are such that the invention is unpatentable in view of 35 U.S.C. § 103.

The appealed rejection predicated obviousness of the claimed invention on the combined teachings of the following references:

                  Di Maio       2,515,949      July 18, 1950
                  Marshall      2,515,960      July 18, 1950
                  Rule I        2,577,484      Dec.  4, 1951
                  Rule II       2,577,485      Dec.  4, 1951
                

The invention defined by the appealed claims relates to a process for the production of colloidal dispersions having silica as the disperse phase in water as the liquid dispersion medium. The problem in this art which appellant asserts was solved by his invention appears to have been how to increase the silica content of such dispersions without rendering the dispersion unstable towards gelation. Appellant asserts that by his claimed process such dispersions can be achieved in which the disperse phase is 30% or more by weight of the dispersion and consists of sub-microscopic silica particles (within the size ranges of about 5 to about 150 millimicrons), the dispersion having a stability toward gelation for at least 6 months at storage temperatures ranging from 0°C. up to 35°C., and without any significant settling of the silica particles.

The specific combination of references relied upon to support the rejection was that all the claims were "unpatentable over Di Maio or Marshall in view of the Rule patents."

Appellant's position here as stated in his brief is:

"* * * The appellant\'s process is unobvious in that it enables the production of valuable end products (stable aquasols of 30% silica content) not heretofore obtainable by processes using a raw or starting material of the nature employed by appellant, which process is in no way taught by, suggested, or even likely to be discovered from the prior art. * * *"

In reaching the ultimate judgment as to obviousness required by section 103, we must analyze the record to determine factually what constitutes the "subject matter as a whole" and the "differences" between it and the prior art. We shall start this analysis by first considering the rejected claims.²

The 19 rejected claims are each directed to "a process of producing stable, alkaline silica aquasols of high silica concentration" which are further specified in the claims as "containing about 30% by weight and more of silica" (cl. 1-6) or "colloidal silica" (cl. 7-19). Except for specifying a control of the salt content of the materials within the claimed limits of 0.025% (cl. 1-6 and 12-15) or "less than 0.01%" (cl. 7-11 and 16-19) the claimed process steps per se are those of the Marshall or Di Maio references.

The position of the board was summarized in its opinion as follows:

"* * * While concededly both Di Maio and Marshall disclose the use of acid-reacting organo aquasols as the initial material containing more than 0.025% by weight of sodium sulfate * * *³, we agree with the examiner that the reduction in the amount of salt in the acidic hyro-organosol to the degree as claimed would be obvious, particularly in view of the Rule patents in which substantially salt free aquasols are taught for the production of basic aquasols of high concentration and good stability. * *"

The specification of the appealed application discusses the Di Maio and Marshall references and states specifically as to Di Maio:

"* * * While the process described in such patent is suitable for producing stable alkaline silica aquasols containing about 15 to 20% by weight of silica, the subsequent concentrating of such sols to a silica content of 25% by weight by the evaporation of water results in a sol having rather limited stability to gelation. Usually such sols will gel within a period of one month at normal storage temperatures, and this period of stability toward gelation is not sufficient for commercially saleable sols which are often stored for periods of 6 months or longer prior to use. Moreover, there is a distinct need in commerce for alkaline silica aquasols containing 30% or more of silica."

As to the Marshall reference, the specification states:

"* * * In accordance with the teachings of this patent it is possible to obtain silica sols containing 20-25% by weight of SiO2 which are stable toward gelation for practical periods of time. However, if such sols are concentrated to a 30% by weight or higher silica concentration by evaporation of water the sols are not stable toward gelation for practical periods of time, and hence the 30% silica sols produced by the process of this patent are not generally satisfactory for commercial sale."

The specification also states:

"The present invention is based on the discovery that stable, alkaline silica aquasols containing about 30% by weight or more of colloidal silica can be prepared from acidic silica hydro-organosols by a process which involves alkalizing the hydro-organsol and removing the organic liquid therein by heating, followed by removal of a portion of the water from the sol by evaporation, provided that the acidic silica hydro-organosol used is free or substantially free of salts."

Thus we see that appellant's process is essentially an improvement on the prior Di Maio and Marshall processes and that a novel critical feature of appellant's process is asserted to reside in the proviso above quoted, i. e., "that the acidic silica hydro-organosol used is free or substantially free of salts."

At this point we turn in our analysis to the Rule patents to determine what they teach the art. It is appellant's position as stated in his brief that the board was "overgenerous in its interpretation of the Rule patents," and that:

"* * * While it is true that the Rule patents do teach specific and special processes for the production of basic aquasols of high concentration and good stability from saltfree aquasols, it is submitted that the Rule patents do not teach that such basic aquasols can be produced from any silica starting or raw material or by any general technique or any sequence of manipulative steps. * * *

* * * * * *

"It has already been pointed out in the discussion of the Rule I and Rule II references in this Brief that these Rule patents are improvements over the process of the Bechtold et al patent * * * in regard to the preparation of high purity aquasols, and that the Bechtold et al process results in stable aquasols of at least 35% silica concentration without the removal of salt contaminants using commercial sodium silicates, with anion contaminants, as the basic raw material. * * *"

The solicitor, however, states in his brief:

"The contention that the Rule patents do not suggest or teach that salt reduction is employed to produce stable aquasols of high concentration * * * is inaccurate. The title of each patent contains the expression `Stable Silica Sols\'. One of the objects clearly stressed in each patent is to provide processes whereby `silica sols of high purity and stability can be made\' * * *. This is particularly pointed out in connection with sols containing `upwards of 35% SiO2\' in the first paragraph of the Rule II specification * * *."

After charging that appellant "has misleadingly misinterpreted the Rule patents" the solicitor further states:

"* * * Thus, he appellant states * * * that Rule I in Example I treats a commercial sodium silicate solution with a cation exchanger and `provides a starting aquasol raw material containing appreciable amounts of sulfate

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