dissenting, with whom RICH, J., joins.
The majority opinion seems to be predicated on what is essentially a hindsight reconstruction of the prior art. I cannot rationalize it except as I ignore what seems to me to be the scope of the invention set forth in the specification and claims. I shall, therefore, begin this dissent by stating what I understand to be the invention.
The specification discloses that “According to this invention, a web or sheet of paper js simultaneously sized and coated.” This is accomplished in a single operation by applying to the paper web an aqueous coating composition which contains both the pigment and the sizing material. The sizing materials which appellants disclose are dimers of aliphatic ketenes. Appellants’ mixture of dimer, pigment and an aqueous dispersing medium ^us provic]es jn a single step a coat-jng for and a sizing of the paper web. The specification also discloses:
... * * Tests have shown that ^ dimer .fl uniformly distributed in the combination sizing and coating composition, and that, when such combination sizing and coating composition is applied to an unsized or partially sized or wholly sized paper web, at least part of the dimer ingredient migrates to the paper web to provide sizing or additional siz-¡ng thereon, and part of said dimer ingredient will, in certain formulas of the improved combination composition later disclosed herein, remain in the final dried coating, thus decreasing the absorption of water *974by the final dried coating.” [Emphasis added.]
The specification discloses further:
“Tests have shown that these dimers, when included in a coating composition, migrate or are transferred from the coating composition to the paper base and provide sizing in the paper base. In prior coating compositions which contain a sizing agent, said sizing agent remains wholly or substantially wholly in the dried coating so that the paper base is not appreciably sized.” [Emphasis added.]
Rejected process claim 12 particularly claims:
“ * * * preparing an aqueous coating composition consisting essentially of a mineral pigment * *, an adhesive binder for said pigment * * and between 0.25% to 4% by weight of total solids in said coating composition of a water repellent dimer of an aliphatic ketene having from 6 to 20 carbon atoms in its aliphatic hydrocarbon group * * * ’>
Rejected claim 13 calls for the mineral-coated paper per se in which both its fibers and its pigmented coating are sized by a sizing agent defined as “a water repellent dimer of an aliphatic ketene.” The claim further requires that the sizing agent is uniformly admixed with the mineral pigment in the coating and that the fibers of the paper web are uniformly sized when the sizing agent migrates from the pigment to the paper fibers.
In claim 14, the paper of the claim is further characterized:
« * * * by said dimer uniformly coating the said pigment at the surface of said coating whereby said pigment is protected by said dimer from the acidity of an acid fountain solution of a lithographic printing press having a pH of about 3.5.”
It is to be noted that in all appealed claims, migration of the dimer from the coating to the paper fibers is vecited.
Dealing as we are here with highly technical concepts of physical chemistry, I do not think we should ignore, as the majority appears to have done, this physical phenomenon which has been thus stressed by appellants. We are told that the dimer and the aqueous vehicle may be mixed to form a particular type of emulsion and that the pigment is then added thereto. Thus, the specification states:
“If desired, the ketene dimer in liquid form, heated if necessary for convenient use, may be stirred into an aqueous coating composition which includes pigment and adhesive, with or without the addition of an emulsifying agent. The preferred practice is to make an aqueous emulsion of the dimer, and to mix said emulsion into the aqueous coating composition.”
The emulsion containing the dimer is, however, disclosed as a particular type of emulsion. Thus appellants state:
“ * * * The initial emulsion which is thus formed has a yellow color, and it is an emulsion of water in oil. When about half of the water has been added, the emulsion becomes an emulsion of oil in water, and the original yellow color changes to a white color.”
One of ordinary skill in the emulsion art would recognize that the properties of such an emulsion can be affected by the presence of finely divided solids in the continuous phase, and particularly so by such solids as may be present at the interface between the continuous and disperse phases of the emulsion. Here, it seems to me, is a substantial difference between the invention for which appellants seek a patent and the disclosures of the prior art. Here, also, we are dealing with an area of technical skills which can well be beyond those of one ordinarily skilled in the paper sizing and coating field. The particle size of the pigments which are a part of the coating composition is described by appellants as preferably being “in a range from 0.2 to 8 mic*975rons.” Such a pigment is known to be a fine powder having a large specific surface area per unit of weight. Such large specific surfaces are known to cause various physical changes in emulsion type vehicles. However, as described in the specification:
“ * * * The dimer is uniformly distributed in said aqueous composition, either in the water thereof, or as a coating on a pigment, or both in the water and on said pigment. In the case of our preferred practice of mixing the mineral pigment with at least part of the adhesive material prior to addition of the ketene dimer to the coating composition we believe that a large part of said dimer remains suspended in the aqueous component of said coating composition up to and including the time that the aqueous coating composition is applied to the paper base. We do not however wish to be limited to this theory, because the essential factor is to provide a sizing agent which enters and sizes the paper from the combination composition.”
The disclosed invention, therefore, is the provision of a single sizing and coating material which can be placed on the paper web in a single step and in which the dimer used as the sizing agent will be transferred from the coating and can migrate into the paper.
I would agree with appellants that this migration is an unobvious phenomenon in physical chemistry. Normally it would seem that a dimer maintained in the disperse phase of an aqueous emulsion would remain there, or if not, that the forces of attraction and adsorption exhibited by the pigment would prevent the migration of the dimer from the coating to the pigment fibers. Or the presence of such solids at the interface of the oil in water emulsion might cause an inversion of the phases in which case it would be expected that the dimer would be freed and thus would no longer be uniformly distributed in the coating composition.
It is noted further that appealed process claim 12 requires an aging step during which “said dimer * * * migrates from said coating composition to the fibers of said sheet and sizes the same.”
The majority opinion concludes that the claimed process and the claimed product are obvious and states:
“We agree with the solicitor that it would be obvious to substitute the ketene dimer sizing agent of Downey or Keim et al. for the rosin sizing agent in the aqueous compositions of mineral pigment and starch disclosed in Ruff.”
Undoubtedly this conclusion has its premise in the further statement of the majority that:
“We have difficulty accepting the distinction urged by appellants that ‘coating’ differs from ‘impregnating’ in this case. It would appear that a porous material like paper would be impregnated to some extent by an aqueous composition applied ‘by various coating techniques’ as Keim et al. suggests, whether the composition is called ‘coating’ or ‘impregnating.’ It seems doubtful that a clearly defined interface between the paper and the coating would result. The differences between coating compositions and impregnating compositions, according to appellants, are in dilution and viscosity. That is, a ‘coating composition usually has a high-solids content and a relatively high viscosity.’ It is clear that none of the claims have any limitations on dilution (solids content) or viscosity. The method claim merely recites ‘applying’ the composition which would appear to include both ‘coating’ processes and ‘impregnating’ processes, even if there is a distinction between ‘coating’ and ‘impregnating,’ and there is no evidence that the art recognizes a distinction. Accordingly, we see no justification for concluding that it is unobvious to employ a sizing agent in either a *976‘coating’ composition or an ‘impregnating’ composition.”
It seems to me that appellants’ position is more realistic than that of the majority on the question of obviousness and I would agree with the position, stated in appellants’ brief, that:
“ * * * -while the art had appreciated that the ketene dimer was an excellent paper sizing agent, the art was totally unappreciative of the ability of the ketene dimer to migrate from a coating composition containing a large amount of mineral pigment prior to appellants’ discovery of this property of the ketene dimer and that as a consequence the feasibility and utility of the claimed process were not apparent to the art. One skilled in the art with the cited references on hand would not be induced to carry out the claimed process, i. e., to apply the ketene dimer to a paper sheet through the agency of a pigmented coating composition.”
Turning to the references, it is seen that Keim is concerned only with the sizing of the paper web by impregnating it with the ketene dimer. He sizes water-leaf paper sheets with a dilute emulsion of the ketene dimer, thoroughly wetting the sheets to the point where the excess emulsion can be removed by squeezing. Admittedly Keim teaches the sizing effectiveness of the ketene dimer. He does not teach, however, that the ketene dimer can and will migrate from an applied paper coating to the paper stock, nor does he indicate that the ketene dimer could be applied in admixture with a paper coating pigment to a paper web in a one-step coating and sizing operation.
The Downey reference relates to an improvement on the teachings of Keim. Downey teaches that the ketene dimer emulsion can have added to it an organic thickening agent for the purpose of preserving the emulsion. Downey, like Keim, is concerned only with impregnating compositions and not coating compositions. There is no indication that mineral pigment could be added to the impregnating emulsions, and, more importantly, there is no teaching that the ketene dimer is capable of migrating from a pigmented coating composition into a paper web.
Ruff discloses an improved type of starch sizing agent and adhesive which is admixed with mineral pigment and can be used for either coating a paper web or impregnating (filling) it.
On what basis then can the majority properly conclude from the disclosures of these references that one skilled in the art would be aware of the property discovered by appellants, i. e., that the ketene dimer would migrate from a pigmented coating into the paper web and size it? I find nothing in these references to indicate such a phenomenon. One skilled in this art would, I think, in fact expect the opposite, i. e., that the ketene dimer would not migrate, in view of the very minute amounts used, the nature of the emulsion in which it forms the disperse phase, and the very large surface area presented by the pigment of the coating.
The claims can be met by the art only as one indulges in a hindsight combination of the references. Appellants grant that if the combination of references is justified,
« * * *■ one can then turn to the question of what its inherent properties would be. Appellants’ position is, however, that in the absence of knowledge of the extraordinary migrating ability of minute amounts of the ketene dimer the teachings of these references would not induce one skilled in the art to attempt the combination. His knowledge and experience would in fact turn him away from doing so. Only by careful experimentation did the appellants come across the surprising discovery of the ability of the ketene dimer to migrate from highly pigmented coating compositions. These references which they were well acquainted with did not tell them this!”
*977I agree with the statement in appellants’ brief:
“The principal point for decision is whether one skilled in the art, in the absence of knowledge about the unusual migrating ability of the ketene dimers and with the knowledge of the effect that a mineral pigment of high surface area has on minor ingredients in coating compositions, would be induced by these references to formulate a pigmented paper coating composition containing the ketene dimer.”
In my opinion, neither the claimed process nor the claimed sized, pigmented paper product is obvious within the meaning of 35 U.S.C. § 103 and I would, therefore, reverse the appealed decision.