OPINION

MURRAY M. SCHWARTZ, District Judge.

The invention of solid crystalline polypropylene has given rise to protracted litigation spanning several decades. In this action, Phillips Petroleum Company ("Phillips"), awarded a product patent in March, 1983 for crystalline polypropylene, has filed a suit against United States Steel Corporation ("U.S. Steel") and Hercules Incorporated for patent infringement. Separate actions have been brought against Phillips by Shell Oil Company, Northern Petrochemical Company, and El Paso Products Company ("El Paso") to obtain a declaratory judgment that the patent is invalid. These actions have been consolidated by orders of this Court dated September 26, 1983, December 22, 1983, and October 5, 1984. All parties adverse to Phillips, except El Paso, ("the movants") have filed a Motion for Summary Judgment urging the patent is invalid because of double patenting. The material facts, largely undisputed, are set forth below. A more comprehensive discussion of the history of the polypropylene patent litigation may be found in Judge Wright's opinion in Standard Oil Co. (Indiana) v. Montedison, S.p.A., 494 F. Supp. 370 (D.Del. 1980), aff'd, 664 F.2d 356 (3d Cir. 1981), cert. denied, 456 U.S. 915, 102 S.Ct. 1769, 72 L.Ed.2d 174 (1982).

Background

In the early 1950's, several companies in the United States and abroad were experimenting with methods of polymerizing various olefins, including ethylene and propylene. By 1953, Phillips Petroleum had developed a new chromium oxide catalyst for use in the polymerization process. Phillips discovered that use of the chromium oxide catalyst in the polymerization of ethylene permitted the production of polyethylene at lower pressures and less cost than had previously been possible. The process had the added advantage of producing polyethylene of higher density and therefore greater commercial utility than was available at the time.

Phillips also employed its new catalyst in the polymerization of propylene, yielding a solid product. Through fractionation of that solid, Phillips was able to isolate a "hard, crystalline translucent solid," later known as solid crystalline polypropylene. The resulting polypropylene, consisting essentially of recurring propylene units, had a high melting point and high density. The present record indicates that prior to that time, the production of crystalline polypropylene was thought impossible.

These discoveries led Phillips to file several related patent applications over the course of three years. All were filed in the names of John P. Hogan and Robert L. Banks, and were assigned to Phillips. Application No. 333,576, entitled a "Process for Polymerizing Olefins and Catalyst Therefor," was filed on January 27, 1953 ("the 1953 application"). A continuation-in-part ("CIP") of that application, Application No. 476,306, was filed on December 20, 1954. Both of these applications disclosed the chromium oxide catalyst and referenced, inter alia, polypropylene as one of the many products which could be made with the catalyst.

In 1955, Guilio Natta and others working on behalf of Montedison, S.p.A., published a series of articles describing crystalline polypropylene in terms different than those contained in Phillips' 1953 application. Montedison filed Application No. 514,099 on June 8, 1955, teaching the manufacture of solid crystalline polypropylene through the use of its newly developed organometallic catalysts. On January 11, 1956, in an effort to provoke an interference with the Montedison application and to secure its patent rights to crystalline polypropylene, Phillips filed another CIP of its 1953 application, Application No. 558, 530 ("the '851 application"), specifically claiming the product of crystalline polypropylene. That application disclosed that crystalline polypropylene could be made both with Phillips' chromium oxide catalyst and with the organometallic catalysts developed by Montedison.

While the '851 application was pending, Phillips filed yet another CIP — Application No. 573,877, filed on March 26, 1956 containing forty-four process claims utilizing the chromium oxide catalyst. On March 4, 1958, Patent No. 2,825,721 ("the '721 patent"), entitled "Polymers and Production Thereof," issued on that process patent application. In September, 1958, the Patent Office instituted Interference No. 89,634 involving Phillips' product patent application and the applications of Montedison and others to determine the priority of invention of the product, crystalline polypropylene. The Board of Patent Interference ("the Board") granted priority to Montedison and on February 6, 1973, the Patent Office issued Patent No. 3,517,344 to Montedison. Review of that determination followed in the federal courts. On January 11, 1980, Judge Wright overruled the decision of the Board and awarded priority to Phillips. Judge Wright assigned Phillips a priority date of at least as early as January 27, 1953, based, inter alia, on Phillips' constructive reduction to practice as evidenced by the 1953 parent application. In addition, Judge Wright held, in the limited context of the interference proceeding, that the product of the Count was patentable to Phillips. 494 F. Supp. at 461.

Judge Wright's rulings in the interference proceeding were affirmed by the Court of Appeals for the Third Circuit in Standard Oil Co. (Indiana) v. Montedison, S.p.A., 664 F.2d 356 (3d Cir. 1981), cert. denied, 456 U.S. 915, 102 S.Ct. 1769, 72 L.Ed.2d 174 (1982), and the matter eventually moved back to the patent office for issuance of a new product patent on solid crystalline polypropylene. At that point, U.S. Steel, one of the movants in this action, filed a protest with the Patent Office pursuant to 37 C.F.R. § 1.291, alleging that the claim involved in the interference action had already received protection under claim 16 of Phillips' '721 patent. The Patent Office considered and denied U.S. Steel's protest and on March 15, 1983, issued Patent No. 4,376,851 ("the '851 patent") on Phillips' product claim. The sole claim of the '851 product patent tracks the claim of Interference No. 89,634. The claim protects the product of:

"[n]ormally solid polypropylene, consisting essentially of recurring propylene units, having a substantial crystalline polypropylene content."

Movants have now raised the identical argument that U.S. Steel brought before the Patent Office — that the '851 patent must be declared invalid for double patenting in light of claim 16 of Phillips' '721 patent. Claim 16 recites:

[a] process which comprises polymerizing propylene at a polymerization temperature in the range 150 to 250° F. with a catalyst comprising, as the sole essential effective catalytic ingredients thereof, chromium oxide supported on silica-alumina, said catalyst containing at least 0.1 weight percent hexavalent chromium at the initial contacting of hydrocarbon with said catalyst, and recovering a resulting solid polymer.

The movants contend that the "resulting solid polymer" of claim 16 of the '721 patent and the product described in the single claim of the '851 patent are the same, as evidenced by their common origin in the 1953 patent application. As a result, they argue that the extension of monopoly afforded by the issuance of the '851 patent should be overturned.

The Law of Double Patenting

Stripped of all its verbiage, movants urge the Court to invalidate the '851 product patent because it represents either the same invention or an obvious variation of claim 16 of the '721 patent. The Court's inquiry must begin with the presumption, set forth in 35 U.S.C. § 282 (1984), that the product patent is valid. In light of that presumption, the burden falls on the challenger to prove the patent's invalidity. See, e.g., American Hoist Derrick Co. v. Sowa Sons, Inc., 725 F.2d 1350, 1358 (Fed. Cir. 1984); Astra-Sjuco, A.B. v. United States International Trade Commission, 629 F.2d 682, 688 (C.C.P.A. 1980); Aluminum Co. of America v. Amerola Products Corp., 552 F.2d 1020, 1024 (3d Cir. 1977); Chicago Rawhide Manufacturing Co. v. Crane Packing Co., 523 F.2d 452, 458 (7th Cir. 1975), cert. denied, 423 U.S. 1091, 96 S.Ct. 887, 47 L.Ed.2d 103 (1976); Griswold v. Oil Capital Valve Co., 375 F.2d 532, 537 (10th Cir. 1966). In double patenting cases, that burden is a heavy one. See Carman Industries, Inc. v. Wahl, 724 F.2d 932, 940 (Fed. Cir. 1983); Transmatic, Inc. v. Gulton Industries, 601 F.2d 904, 913 (6th Cir. 1979); Reynolds Metals Co. v. Continental Group, Inc., 525 F. Supp. 950, 972 (N.D.Ill. 1981).

In this action, movants' double patenting challenge involves a comparison of the claim of Phillips' '851 product patent with claim 16 of the expired '721 patent. Both patents have as their genealogical parent the 1953 application. The parties agree that the parent application and the two patents each disclose the invention of normally solid crystalline polypropylene and teach the preparation of that product through use of Phillips' chromium oxide catalyst. Patents which issue from copending applications may, however, overlap with respect to the information they disclose without necessarily resulting in double patenting. See In re Swett, 451 F.2d 631, 632 (C.C.P.A. 1971); In re White, 405 F.2d 904, 906 (C.C.P.A. 1969), Tidewater Patent Development v. Kitchen, 371 F.2d 1004, 1009 (4th Cir. 1966), cert. denied, 389 U.S. 821, 88 S.Ct. 46, 19 L.Ed.2d 74 (1967). It is the claims of the patent, rather than the information disclosed in the specification, that delineate the scope of the monopoly and are critical to the double patenting inquiry. In re Baird, 348 F.2d 974 (C.C.P.A. 1965). Indeed, the doctrine of double patenting, the prime function of which is to prevent an unwarranted extension of the statutory monopoly period of a valid patent, is concerned only with "attempts to claim related subject matter twice. It does not preclude a second patent on subject matter which is disclosed but not claimed in the first patent." 3 Chisum Patents § 9.01.

Although the specification confers no monopoly, it may, in certain instances, aid in determining the meaning and scope of the claims and hence is available as a reference in establishing the extent of protection carved out by the patent. In re Vogel, 422 F.2d 438, 441 (C.C.P.A. 1970). Where the claim language on its face admits of only one interpretation, as for example, the product claim of the '851 patent, it is unnecessary to refer to the specification to ascertain the meaning of the claim. However, where the claim language is unclear, ambiguous, or is otherwise susceptible to differing interpretations as to the scope of the conferred statutory monopoly, resort to the specification is appropriate in resolving a defense of double patenting.

After the scope of the monopoly of each patent is defined by fixing the perimeters of the relevant claims, the Court must then determine whether double patenting exists. The difficulty presented by the chemical subject matter of these particular patents is exacerbated by the dearth of product-process double patenting cases. One may glean from the existing cases, however, that the Court's analysis in this context necessitates the same two-part inquiry applied routinely in other types of double patenting cases. First, the Court must determine whether the claims in question represent the same inventive concept. See, e.g., In re Taylor, 360 F.2d 232, 234 (C.C.P.A. 1966). If they do not, the Court must then consider whether one patent reflects merely an obvious variation of the other and vice versa. In re Lyons, 364 F.2d 1005 (C.C.P.A. 1966).

The first prong of the double patenting test, commonly referred to as "same invention" double patenting, is derived from the express language of the Patent Act. 35 U.S.C. § 101 provides: "Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title." Id. (emphasis added). This section prohibits the granting of more than one patent on a single inventive concept, and may be invoked as a basis for invalidating a patent where the invention is already protected by another patent to the same inventor. See, e.g., In re Vogel, 422 F.2d 438, 441 (C.C.P.A. 1970) (comparison of process patents); In re White, 405 F.2d 904, 906 (C.C.P.A. 1969) (comparison of process patents); In re Boylan, 392 F.2d 1017, 1021 (C.C.P.A. 1968) (comparison of composition claim and method for using composition). The ultimate question in a same invention double patenting inquiry is whether the identical subject matter is claimed in both patents. See, e.g., Carman Industries, Inc. v. Wahl, 724 F.2d at 940 (in same invention double patenting, the test is whether the patents "claim the same subject matter"); In re Vogel, 422 F.2d at 441 ("[b]y `same invention' we mean identical subject matter; . . . same invention means identically same invention"); In re White, 405 F.2d at 906 (a same invention double patenting analysis "requires a factual inquiry into whether the claims . . . are directed to the same subject matter, or invention. . . . If there be any substantive difference, and not merely a difference in language, then the inventions are not the same no matter how small or how obvious those differences may be").

In the context of product and process patents, the United States Supreme Court held early on that where both a process and the resulting product were new, both were patentable. Rubber Co. v. Goodyear, 76 U.S. (9 Wall) 788, 796, 19 L.Ed. 566 (1870). The Court there recognized: "[t]he patentability, or the issuing of a patent as to one, in nowise affects the rights of the inventor or discoverer in respect to the other. They are wholly disconnected and independent facts." Id. But see Mosler Safe Lock Co. v. Mosler, 127 U.S. 354, 361, 8 S.Ct. 1148, 1151, 32 L.Ed. 182 (1888) ("[a]fter a patent is granted for an article described as made by causing it to pass through a certain method of operation to produce it, . . . the inventor cannot afterwards, on an independent application, secure a patent for the method or process").

The seemingly bright line drawn by the Supreme Court in Goodyear has grown dim over time. The Court of Appeals for the Federal Circuit has not yet had an opportunity to speak on the double patenting issue with respect to product and process patents. In the Court of Customs and Patent Appeals, whose decisions are binding as precedent for the Federal Circuit, South Corp. v. United States, 690 F.2d 1368 (Fed. Cir. 1982), the issuance of two patents for a process and its resulting product has been neither routinely permitted nor categorically prohibited. Instead, a conceptual approach has been applied to determine whether the two patents, when properly construed, each represent new and different subject matter. For example, in In re Freeman, 166 F.2d 178 (C.C.P.A. 1948), the applicant had already patented an extraction process for use in the manufacture of paint compositions. In a separate application, the inventor sought protection of the paint composition itself, defined not by any unique properties, but by its process of manufacture. Id. at 179. Although the Court acknowledged that the scope of the process limitations differed with respect to the two claims, it nevertheless denied the composition claim on the ground of double patenting. The Court reasoned that the claim to the paint compositions did not disclose any new matter, the "[f]ormulation of paints [being], of course, conventional" and the claims not alleging any new properties inherent in the composition. Id. at 181.

Within the overlay of its conceptual approach, the Court of Customs and Patent Appeals has, in some instances, applied a test to facilitate its determination of whether product and process patents claim the same invention. According to that test, a charge of double patenting will not be sustained if the product can be made by processes other than that secured by the issued process patent or the process can produce other products not protected by the product claim. See In re Taylor, 360 F.2d 232, 235-36 (C.C.P.A. 1966) (process of making collagen film not same invention as product of film itself); In re Cady, 77 F.2d 106, 109 (C.C.P.A. 1935) (process of manufacturing roofing material not same invention as that of roofing composition); see also 1 Horwitz, Patent Office Rules and Practice § 79.12. This approach parallels the "cross-reading" test applied in other areas of double patenting and adopted by the Federal Circuit in the context of design versus utility patents. See Carman Industries, 724 F.2d at 940; see also In re Vogel, 422 F.2d 438, 441 (C.C.P.A. 1970) (similar process claims subjected to crossreading test of double patenting). The application of the cross-reading test in other types of double patenting cases is at least some indication that the Court of Appeals for the Federal Circuit will follow a like approach in evaluating same invention, product-process double patenting.

Obvious-type double patenting similarly involves a reciprocal analysis. Double patenting will be established on the basis of obviousness only if each patent is obvious from the other. See Carman Industries, 724 F.2d at 940 (design patent relating to external surfaces of storage bins not obvious from utility patent on interior construction); In re Vogel, 422 F.2d at 442 (method for packaging beef not an obvious variation of method for packaging pork). Unlike the question of "same invention" the doctrine of "obviousness" in the context of double patenting has no statutory basis. Rather, it is a judicially created doctrine intended to prevent the extension of monopoly to claims in a second patent not "patentably distinct" from claims of the first patent. In re Thorington, 418 F.2d at 537; see also Carman Industries, 724 F.2d at 940. Under obvious-type double patenting, the claims in question may not be considered prior art with respect to each other. In re Braithwaite, 379 F.2d 594, 600 n. 4 (C.C.P.A. 1967). They must, however, be analyzed to determine whether one is obvious from the other in light of all other existing prior art. Id. Patents which are obvious from one another will not be deemed invalid if one contains a terminal disclaimer to ensure that both patents will expire at the same time. In re Vogel, 422 F.2d at 442; In re White, 405 F.2d at 906.

The Phillips Patents

Turning to the patents in question, the Court must first scrutinize the language of the claims to ascertain the scope of the monopoly obtained. The meaning of the sole claim of the '851 patent is clear on its face. The claim is for a product defined in terms of its properties — a product that is 1) normally solid polypropylene; 2) consisting essentially of recurring propylene units; and 3) having a substantial crystalline polypropylene content. A product would not fall within the confines of the claim unless all three characteristics were present. The patent provides a monopoly on the product per se, and is not limited to the product as produced by any particular method.

The meaning of claim 16 is less readily apparent. On the surface, that claim sets forth a particular polymerization process containing several critical limitations — the process "comprises," or in other words, includes, the polymerization of propylene at a given temperature with a particular catalyst. The claim also indicates that performance of the process will yield "a resulting solid polymer."

No precise description of that solid polymer is contained in the claim. Movants do not seriously contest that the term "solid" may be used to describe a substance that is either crystalline or amorphous in nature. However, they assert that in this context, the solid polymer recovered by the process of claim 16 connotes solid crystalline polypropylene, identical in every respect to the product described in the single claim of the '851 patent. In support of their theory, movants rely on a portion of the specification which defines the term "solid" as it is used in connection with the polymerization of propylene. That passage refers to a process of "fractionation," which, when performed on the total polymer produced by the process set forth in claim 16, would enable one skilled in the art to isolate from the total substance a tacky polymer and a high molecular weight solid polymer. Movants emphasize that the specification expressly defines the term "solid" as this high molecular weight substance obtained after fractionation. Thus, in interpreting claim 16, movants would, in effect, read an additional process step — fractionation — into the phrase "and recovering a resulting solid polymer."

Extending their analysis a step further, movants point to language in the specification which describes this high molecular weight, fractionated solid in sufficient detail that the skilled polymer chemist would recognize the disclosure of a crystalline substance. Movants highlight the identical language in the 1953 application which Phillips' successfully relied upon to establish its constructive reduction to practice of crystalline polypropylene in its suit for priority of invention over Montedison. See Standard Oil, 494 F. Supp. at 421. Thus, movants contend that claim 16, read in light of the patent specification, claims a process for the production of a particular substance, and claims the fractionation of that substance to yield solid crystalline polypropylene as described in the '851 patent. That conclusion forms the linchpin on which movants' double patenting challenge is based.

Phillips, on the other hand, eschews this interpretation of the claim. Although Phillips concedes that the '721 patent, read in its entirety, provides all the data needed to produce solid crystalline polypropylene from the process of claim 16, Phillips denies that the claim itself states a process directed solely to the manufacture of solid crystalline polypropylene. Phillips steers the Court's attention away from the patent specification and back to the language of the claim, emphasizing the obvious omission of fractionation. All parties agree, unless the product produced by the specified process steps of the claim were subjected to the added step of fractionation, solid crystalline polypropylene would never be recovered. Consequently, Phillips maintains that the absence of fractionation from the wording of the claim vitiates movants' assertion that Phillips has previously obtained a monopoly on a process which, if followed, would inevitably yield the product, solid crystalline polypropylene.

In addition, Phillips observes that claim 16 denotes a process "comprising" the polymerization of propylene. Phillips urges that use of the word "comprises" permits the addition of other monomers in conjunction with propylene as feed to the process and therefore establishes that the process of claim 16 is not directed solely to preparation of the product of the '851 patent.

The differences in the parties' interpretations of the claims must be resolved before the Court can compare the patents to determine if double patenting exists. Careful consideration of the claim language and the patent specification in light of the arguments presented compels a finding that movants have misinterpreted the scope of patent protection afforded by claim 16. That provision undisputedly asserts a claim to a process per se. As such, it secures a monopoly for the production of a solid polymer by means of specified process steps. That monopoly cannot be expanded to include additional process steps found in the specification but not expressly claimed. Thus, fractionation cannot be read into the language of claim 16 to become part of the patent monopoly. Moreover, the scope of claim 16's monopoly, limited in terms of the catalyst used and the temperature at which the process is performed, is not restricted by the properties of the product produced, beyond the fact that the product must be a solid polymer and must contain propylene. Movants in effect ask the Court to search the patent specification for evidence of additional properties inherent in the product resulting from claim 16's process, and then argue that those properties — in this case crystallinity and the recurrence of propylene units — should be read as limitations upon the scope of the monopoly. Claim 16 is not, however, so limited. Its concern is with the acquisition of a patent on a particular process, rather than with the specifics of the product produced. Consequently, claim 16 may not be read as limited to a process for the manufacture of solid crystalline polypropylene consisting essentially of recurring propylene units. Indeed, the process claim would equally protect against the manufacture of a product lacking these specific qualities but produced by the process of claim 16 including propylene as feed to the process.

Moreover, because the process claim uses the word "comprises," it does not purport to limit its protection to a process using only propylene as feed. See, e.g., In re Fenton, 451 F.2d 640, 642 (C.C.P.A. 1971); In re Cone, 121 F.2d 470, 472 (C.C.P.A. 1941). Rather, claim 16 contemplates that the process described could be performed on propylene in combination with other substances, as long as a solid containing propylene was ultimately produced. Indeed, the specification makes express reference to the polymerization of propylene in conjunction with other monomers. It is therefore evident that the monopoly carved out by the claim encompasses the polymerization of propylene through the process described, as well as the polymerization of propylene by that same process in combination with other monomers.

Having analyzed the language of the claims, there remains the question of whether double patenting exists, either because the claims represent the same invention or because one is an obvious variation of the other. With respect to same invention double patenting, I do not profess to determine whether a conceptual approach or the cross-reading test stands as the better mode of analysis. Each has its advantage for the courts and prospective litigants, the former being more adaptable to factual variances and the latter facilitating predictability of result. For purposes of this case either approach yields the same result — claim 16 of the '721 patent and the single claim of the '851 patent are directed to different inventions.

First, claim 16 pertains to a process, whereas the '851 patent applies to a product per se. Each provides a presumptively valid assertion that the subject matter claimed is novel, useful and nonobvious. As such, the two claims represent different, though related contributions to the field of polymer chemistry. The process claim indicates one of many uses of Phillips' chromium oxide catalyst in the polymerization process. The composition of that catalyst was itself the subject of several claims in the '721 patent. The '721 patent also contains a series of process claims, claim 16 among them, elucidating use of a specific catalyst in the polymerization of a multitude of olefins. Some of the polymers produced by those claims were themselves alleged to be novel while others were not. But the novelty of the product resulting from the process of each claim was not the primary concern of the patent office. The claims were allowed because of the novelty of the chromium oxide catalyst essential to the processes. Similarly, Claim 16, represents one use of Phillips' new chromium oxide catalyst in a polymerization process. It does not purport to claim the different inventive concept of the product of the '851 claim.

Moreover, claim 16 does not state a process for the manufacture of solid crystalline polypropylene as defined in the '851 patent because it lacks any mention of fractionation. There is therefore missing the "identity of subject matter" between the patents which is essential to a finding of same invention double patenting. See In re Vogel, 422 F.2d at 441; In re White, 405 F.2d at 906.

Phillips' patents likewise survive analysis under the cross-reading test of double patenting — the product of the '851 patent may be made by other processes and the process of claim 16 may be used to make other products. First, claim 16 as interpreted by the Court, results in a product other than the solid crystalline polypropylene of the '851 patent. Only by subjecting that product to fractionation, will solid crystalline polypropylene be recovered. Conversely, the product of the '851 patent maybe made by a significantly different process — the organometallic process which has been patented by Montedison and which was disclosed in the '851 specification.

Movants challenge the propriety of considering the organometallic process in the double patenting analysis since that process was invented after Phillips' development in 1953 of solid crystalline polypropylene. See Standard Oil, supra. Indeed, since Phillips relied on the date of its 1953 application to obtain priority of invention and secure the '851 patent, movants maintain that the double patenting inquiry should be limited to the 1953 date. Neither the movants, in presenting this argument, nor Phillips in rebutting it, have cited any compelling authority to support their respective positions. Nor has the Court's independent research disclosed any case law expressly on point. Movants strenuously argue that the purpose of the double patenting inquiry militates against consideration of the organometallic process. They urge that since the question is whether the patents represent the same or different inventive concepts, the focus should be restricted to the established date of invention — in this case 1953. Movants maintain that the organometallic process may not be considered for double patenting purposes because, while known and even mentioned in the '851 specification, it was not known at the time the 1953 application was filed.

While movants' argument contains superficial appeal, closer examination reveals its flaws. First, it inappropriately weds priority of invention with the double patenting doctrine. The purpose of the former is to determine who, among potential inventors, is considered first for purposes of United States patent law. The primary, albeit not the only purpose of the latter doctrine is to prevent the claim of like subject matter in more than one patent.

Second, consideration of subsequent advancements in the art in the double patenting analysis neither expands nor contracts the scope of the invention claimed. It merely serves as an aid in determining whether the whole of the inventor's contribution to the art was deserving of one or more than one patent. In this respect, inclusion of a later developed process complements the policy underlying the patent statute. It is a goal of that act to encourage continual innovation by conferring upon the inventor a statutory monopoly with its potential for economic gain. To achieve that goal, it is important that the inventor receive protection to the full extent of his or her invention. If one patent is sufficient to ensure that protection, double patenting steps in to prohibit the issuance or retention of a second patent to the same inventor. If, on the other hand, a single patent leaves a related invention unclaimed and therefore unprotected, a second patent may be in order. Thus, the cross-reading test of double patenting serves as one means by which a court can determine whether a single patent has already provided the protection due, rendering a second patent superfluous. To that end, it would be logical to consider even a later developed process to ascertain whether one patent, standing alone, provides all the protection that the inventor is entitled to.

Third, the peculiar sequence of events in this case has resulted in the issuance to Phillips of a product patent which discloses a process undeveloped and unknown to it at the time the initial application was filed. Once known, Phillips correctly disclosed but did not claim the organometallic process as a process for making solid crystalline polypropylene. It would be anomalous in a double patenting inquiry to ignore a process which is disclosed in the very patent being examined by the Court. The Court declines to conduct the double patenting analysis with blinders so as to avoid recognition or discourage disclosure of advances in process technology as a means of making a product patent. I therefore conclude that on these facts, it is appropriate to consider the organometallic process which stands as an alternative, albeit a subsequent, means of preparing the product of the '851 patent. Because this alternative process should be considered in this double patenting inquiry, no same invention double patenting exists.

Attention is now turned to the question of whether claim 16 of the '721 patent and the sole claim of the '851 patent constitute "obvious" type double patenting. The test is whether the subject matter of the claim of the '851 product patent "would have been obvious" from claim 16 of the '721 process patent, and vice versa. See Carman Industries, Inc. v. Wahl, 724 F.2d at 940. There is no basis in this record for a conclusion that the product of the '851 patent, exhibiting a structure of recurring molecules of propylene and having the properties of solidity and crystallinity, would have been obvious to one skilled in the art given only the claim 16 process. As has been stated previously, the polymerization of propylene had, prior to Phillips' invention, only been known to produce an amorphous, rather than a crystalline substance. Moreover, it would be necessary that the product obtained by the process of claim 16 be fractionated before solid crystalline polypropylene would be obtained.

Equally important, movants have not, and cannot, make a showing that the process for making polypropylene would have been obvious from the claim of the '851 patent. Movants do not contend, and no record support has been cited for the proposition, that the process of claim 16 could be ferreted out merely from knowledge of the product of the '851 patent. I am therefore not persuaded that the '851 patent should fail under the test for obvious type double patenting.

Conclusion

The prolonged litigation over the rights to a product patent on polypropylene has worked a rather curious anomaly in the field of polymer chemistry. The patent on Phillips' chromium oxide catalyst, which may be used but has never achieved commercial success in the production of crystalline polypropylene, has long since expired. Moreover, royalties on the product of polypropylene were paid to Montedison until 1980. Phillips may now continue to exact royalties for that same product until the expiration of its '851 patent. Nonetheless, the delays in determining the rightful inventor of polypropylene do not justify depriving Phillips of the fruits of its invention. Accordingly, an order will be entered in this matter denying movants' Motion for Summary Judgment predicated on double patenting.