Board of Patent Appeals and Interferences
Patent and Trademark Office (P.T.O.)
*1 EX PARTE FREDERICK J. KAROL, ISAAC J. LEVINE, AND KATHLEEN F. GEORGE
Appeal No. 86-0513
June 16, 1988
Application for Patent filed March 13, 1984, Serial No. 587,005, which is a Continuation-in-Part of Serial No. 480,296, filed March 29, 1983. Preparation Of Low Density, Low Modulus Ethylene Copolymers In A Fluidized Bed.
John S. Piscitello et al. for Appellants
Primary Examiner--Edward J. Smith
This is an appeal from the examiner's decision refusing to allow claims 1 through 62, which are all the claims in this application.
Claim 1 is representative:
1. A continuous process for producing ethylene copolymers having a density of less than 0.91 g/cm3 and a 1% secant modulus of less than 140,000 kPa in a fluidized bed without particle agglomeration,
said copolymers containing no more than 94 mol percent of polymerized ethylene and at least 6 mol percent of polymerized alpha olefin containing from 3 to 8 carbon atoms,
which comprises continuously contacting, in a fluidized bed reaction zone, at a temperature of from 10<<degrees>> C up to 80<<degrees>> C and a pressure no greater than 7000 kPa, a gaseous mixture containing (a) ethylene and at least one higher alpha olefin containing 3 to 8 carbon atoms, in a molar ratio of such higher alpha olefin to ethylene of from 0.35:1 to 8.0:1, and (b) at least 25 mol percent of at least one diluent gas, with particles of a catalyst system comprising a precursor composition having the formula
wherein R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR'
wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,
X is selected from the group consisting of Cl, Br, I, and mixtures thereof,
ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,
m is 0.5 to 56,
n is 0, 1 or 2,
p is 2 to 116, and
q is 2 to 85,
said precursor composition being diluted with an inert carrier material and completely activated with an organoaluminum compound having the formula
wherein X' is Cl or OR''',
e is 0 to 1.5,
f is 0 or 1, and
d + e + b = 3,
said activator compound being employed in an amount such as to provide a total aluminum: titanium molar ratio in said reaction zone from 10:1 to 400:1.
The prior art references relied on by the examiner are:
Goeke et al. (Goeke) 4,302,565 Nov. 24, 1981
Karol et al. (Karol) 4,390,677 Jun. 28, 1983
Matsuura et al. (British Patent) 2,034,336 Jun. 4, 1980
*2 The issues presented for review are: (1) whether the examiner correctly entered a provisional rejection of claims 1 through 62 for "obviousness-type" double patenting over claims 1 through 30 of copending application Serial No. 480,296; and (2) whether the examiner correctly rejected claims 1 through 62 under 35 USC 103 as unpatentable over the combined teachings of the above-cited references.
Considering first the double patenting rejection, we are mindful that claims 1 through 30 of copending application Serial No. 480,296 stand rejected. In Appeal No. 680-67, decided this date, we affirmed the examiner's rejection of those claims under 35 USC 103 based on the combined teachings of Karol, the British Patent, and Goeke. This raises the threshold question whether the examiner correctly entered a provisional rejection of claims 1 through 62 for double patenting over claims 1 through 30 of the related application, even though the latter claims stand rejected. We hold that he did.
In a similar situation presented in In re Wetterau, 356 F.2d 556, 148 USPQ 499 (CCPA 1966), the court sanctioned a provisional double patenting rejection of the appealed claims over the allowed claims of a commonly assigned, copending application taken in view of "secondary" art. The court emphasized the provisional nature of the rejection, that is, if a patent were not to issue on the copending application, the double patenting rejection would necessarily evaporate. But the court approved the practice of rejecting claims on the allowed claims of copending applications on double patenting grounds in view of "the benefits which such a practice appears to give to the interested parties". As stated in footnote 2 of Wetterau, that practice "appears to benefit both the applicant and the Patent Office, the former because he is made aware of the possible existence of 'double patenting' at an early date and has an opportunity, if he so desires, to elect which application to let issue, and the latter because of the hastening of the prosecution".
In our view, the policy reasons enunciated in Wetterau apply equally to the instant case. True, claims 1 through 30 in copending application Serial No. 480,296 stand rejected, not allowed. Nevertheless, the examiner's entry of a provisional double patenting rejection in this case "appears to benefit both the applicant and the Patent Office, the former because he is made aware of the possible existence of 'double patenting' at a early date and has an opportunity, if he so desires, to elect which application to let issue, and the latter because of the hastening of the prosecution". We hold, therefore, that the examiner's provisional rejection of claims 1 through 62 for double patenting over claims 1 through 30 of the related application does not fall merely because the latter claims stand rejected.
*3 Turning to the merits of the double patenting rejection, we note a substantial overlap in operating conditions set forth in the respective sets of claims. Independent claim 1 before us recites a temperature range of 10-80<<degrees>>>> C and a molar ratio of higher alpha olefin to ethylene of 0.35:1 to 8.0:1. Independent claim 1 in copending application Serial No. 480,296 recites a temperature range of 30-80<<degrees>> C and a molar ratio of higher alpha olefin to ethylene of 0.35:1 to 6.0:1 but, in all other respects, is identical with the independent claim before us. Moreover, appellants do not controvert the examiner's position that claims 1 through 62 define merely an obvious variation of the invention claimed in copening application Serial No. 480,296. Rather, appellants state that "[i]n the event application Serial No. 480,296 should issue as a patent, appellants agree to file a terminal disclaimer to overcome this rejection". See the main Brief, page 40. On these facts, we shall summarily affirm the examiner's provisional double patening rejection.
Considering next the rejection under 35 USC 103, we find that each of the Karol and the British patents is relevant for its disclosure of the same basic process set forth in appealed claim 1. Specifically, each reference discloses a continuous process for preparing ethylene copolymers in a fluidized bed by copolymerizing ethylene and a higher alpha olefin therein in the vapor phase and in the presence of the same catalysts employed by appellants. Note particularly Example 1, Runs No. 1 through 13 of Karol, continuously conducted in a fluid bed reactor. Note also the following disclosure in the British patent, page 3, lines 104-108: "In the polymerization reaction, a mixture [of] ethylene and butene-1 is allowed to polymerize in vapor phase. A known type of reactor, such as a fluidized bed or an agitation vessel, may be used [Emphasis added]."
Appellants predicate patentability on the particular combination of process conditions recited in claim 1, namely, the recitation therein of a specific temperature range and a minimum mol percent of at least one diluent gas. In this regard, claim 1 recites conducting the reaction "at a temperature of from 10<<degrees>> C up to 80<<degrees>> C" and using "at least 25 mol percent of at least one diluent gas". According to appellants, the prior art would not have suggested these process conditions which enable the preparation of low density, low modulus ethylene copolymers in a fluidized bed without particle agglomeration. We disagree.
With respect to temperature, we note that Karol's preferred operating range (30-115<<degrees>> C) substantially overlaps the range set forth in claim 1 (10-80<<degrees>> C) and, moreover, that Karol points in the direction of using lower temperatures for preparing products having a lower density. See Karol, column 10, lines 44 through 55. We are persuaded that a person having ordinary skill in the art would have been motivated to make low density, low modulus copolymers because these materials are known to be useful in the preparation of tubing, hoses, and in other applications where flexibility and toughness are desirable. In doing so, the artisan would have found it obvious to use temperatures at the lower end of Karol's preferred range. Moreover, the British Patent discloses a vapor phase, copolymerization reaction which (1) produces low density copolymers of ethylene and butene; (2) overcomes the problem of polymer adhesion to the reactor; and (3) uses temperatures which substantially overlap or fall within the range set forth in appellants' claim 1. See particularly the temperatures disclosed by the British Patent in page 3, lines 109 through 111 and see page 5, Example 2. In view of the combined teachings of Karol and the British Patent, we have no doubt that a person having ordinary skill in the art would have arrived at the relatively low operating temperatures set forth in appealed claim 1 with the expectation of continuously preparing relatively low density copolymers of ethylene.
*4 With respect to the use of a diluent gas, we note Karol's disclosure that "[a]ny gas inert to the catalyst and reactants can also be present in the gas stream" and "[a] gas which is inert to the catalyst such as nitrogen or argon is used to carry the partially or completely reduced precursor composition, and any additional activator compound or nongaseous chain transfer agent that is needed, into the bed" and "[t]he feed stream of gaseous monomer, with or without inert gaseous diluents, is fed into the reactor". See Karol, column 10, lines 17 and 18 and see column 11, lines 9 through 13 and 67 and 68. We further note the general rule that "normally, it is to be expected that a change in temperature, or in concentration, or in both, would be an unpatentable modification" of an otherwise known process. In re Aller, 220 F.2d 454, 105 USPQ 233, 235 (CCPA 1955). Following that general rule, we find that the claim 1 recitation of "at least 25 mol percent of at least one diluent gas" does not impart patentability to appellants' process absent a clear and convincing showing of unexpectedly superior results. This is particularly so where the prior art contains ample suggestion to feed an inert gaseous diluent or diluents into the fluid bed reactor and, moreover, the prior art correlates the use of relatively low operating temperatures with the preparation of products having a relatively low density.
Appellants rely on comparative evidence presented in their specification disclosure, particularly Examples 3 through 9 therein, as rebutting the examiner's prima facie case of obviousness. That reliance is misplaced.
Primarily, the comparative evidence establishes that variation among selected parameters, within the broad ranges set forth in appealed claim 1, leads to an inoperative process. For example, "when the reaction temperature in Example 4 was increased to 65<<degrees>> C, reactor fouling occurred due to particle agglomeration forcing a halt to polymerization". See the specification, page 28, lines 1 through 4. By the same token, "when operating at substantially the same conditions as in Example 6, but employing a reaction mixture containing 36 mol per cent nitrogen and a reaction temperature of 65<<degrees>> C, reactor fouling occurred due to particle agglomeration forcing a halt to polymerization". See the specification, page 30, lines 1 through 6. Again, "when the ratio of propylene to ethylene in Example 8 was increased to 1.9, reactor fouling occurred due to particle agglomeration forcing a halt to polymerization". See the specification, page 32, lines 6 through 9. It can be seen that in each instance where particle agglomeration forced a halt to polymerization, nevertheless, the temperature or propylene to ethylene ratio was within the scope of appealed claim 1. This raises the question whether appellants' specification constitutes an invitation to experiment; whether the scope of protection sought is supported and justified by the specification disclosure; and whether appellants "overclaim" their invention by including within the scope of claim 1 numerous embodiments which are nonoperative. See Graver Tank & Mfg. Co., Inc. v. Linde Air Products Co., 80 USPQ 451 (U.S.Sup.Ct.1949). In any event, the specification evidence does not show that appellants' claimed process, considered as a whole, provides unexpectedly superior results.
*5 Further with respect to the specification evidence, we point out that appellants have the burden of establishing that any differences actually obtained would not have been expected by a person having ordinary skill in the art. See In re Freeman, 474 F.2d 1318, 177 USPQ 139 (CCPA 1973). Appellants have not met that burden in this case. On the contrary, the prior art here points in the direction of preparing relatively low density copolymers of ethylene by operating at relatively low temperatures. Appellants' comparative evidence appears to confirm what would have been expected by a person having ordinary skill who would have adjusted the temperature downwardly, per the teachings of the prior art, to obtain the suggested and desired results.
We are mindful of the Wagner affidavit filed under Rule 132 and made of record April 26, 1985. That affidavit presents no additional objective evidence of non-obviousness. Rather, Dr. Wagner offers his opinion with respect to "results which would likely be obtained" when operating within the scope of appealed claim 1. Like the situation in In re Lindell, 385 F.2d 453, 155 USPQ 521 (CCPA 1967), we find that this opinion affidavit is entitled to little weight. Furthermore, as discussed supra, the specification evidence establishes that variation among selected parameters, within the broad ranges set forth in appealed claim 1, leads to an inoperable process. The Wagner affidavit does not controvert that fact.
We note appellants' separate argument with respect to claims 9 through 12, 19 through 30, 33 through 36, and 43 through 54 "which all recite the presence of at least one diene in the reaction mixture". See the main Brief, paragraph bridging pages 28 and 29. In this regard, we point out that the British patent discloses this very feature. See the reference disclosure at page 4, lines 53 through 58.
With respect to the prior art rejection we have evaluated and weighed all the evidence in this case, including: (1) the prior art references cited and relied on by the examiner; (2) the evidence presented in appellants' specification disclosure; and (3) the Wagner affidavit. In re Piasecki, 745 F.2d 1468, 223 USPQ 785 (Fed.Cir.1984); In re Rinehart, 531 F.2d 1048, 189 USPQ 143 (CCPA 1976). It is our judgment that the evidence of obviousness here outweighs the evidence of non-obviousness.
In conclusion, we hold that the examiner correctly entered a provisional rejection of claims 1 through 62 for "obvious-type" double patenting over claims 1 through 30 of co-pending application Serial No. 480,296. We further hold that the examiner correctly rejected claims 1 through 62 under 35 USC 103 as unpatentable over the combined teachings of Karol, the British Patent, and Goeke.
For the reasons well stated by the examiner in his Answer, as amplified above, the examiner's decision refusing to allow claims 1 through 62 is affirmed.
*6 37 CFR 1.136(a) does not apply to the times for taking any subsequent action in connection with this appeal.
BOARD OF PATENT APPEALS AND INTERFERENCES
Saul I. Serota
James A. Seidleck
Sherman D. Winters
William F. Smith