Jan Van Egmond et al.Download PDFPatent Trials and Appeals BoardMay 28, 20212020001647 (P.T.A.B. May. 28, 2021) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 12/941,440 11/08/2010 Jan W. Van Egmond GRACE 3.0-021 9747 122913 7590 05/28/2021 GRACE Lerner, David, Littenberg, Krumholz & Mentlik, LLP 20 Commerce Drive Cranford, NJ 07016 EXAMINER BLACKWELL, GWENDOLYN ART UNIT PAPER NUMBER 1762 NOTIFICATION DATE DELIVERY MODE 05/28/2021 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): eOfficeAction@lernerdavid.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE _________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte JAN W. VAN EGMOND and PING CAI __________ Appeal 2020-001647 Application 12/941,440 Technology Center 1700 ___________ Before ADRIENE LEPIANE HANLON, BRIAN D. RANGE, and DEBRA L. DENNETT, Administrative Patent Judges. HANLON, Administrative Patent Judge. DECISION ON APPEAL A. STATEMENT OF THE CASE The Appellant1 filed an appeal under 35 U.S.C. § 134(a) from an Examiner’s decision finally rejecting claims 1–7, 9, 10, 12–18, and 20–22. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant identifies the real party in interest as W.R. GRACE & CO. CONN. Appeal Brief dated July 15, 2019 (“Appeal Br.”), at 1. Appeal 2020-001647 Application 12/941,440 2 Independent claim 1, the sole independent claim on appeal, is reproduced below from the Claims Appendix to the Appeal Brief. The limitations at issue are italicized. 1. A method for polymerizing propylene, optionally with one or more additional comonomers, comprising: a. introducing catalyst into a gas phase reactor, wherein the catalyst comprises one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and an internal electron donor and wherein the gas phase reactor has a reactor temperature greater than 70°C; b. introducing a recycle fluid comprising propylene and optionally comonomer into the gas phase reactor, said recycle fluid having a given dew point at the inlet to the gas phase reactor; c. introducing a mixed external electron donor system to the reactor, wherein the mixed external electron donor system comprises at least one selectivity control agent and at least one activity limiting agent into the gas phase reactor; wherein: (i) the activity limiting agent is a carboxylic acid ester, a diether, a poly(alkene glycol), a diol ester, or a combination thereof; and (ii) the selectivity control agent is selected from the group consisting of an alkoxysilane, an amine, an ether, a carboxylate, a ketone, an amide, a carbamate, a phosphine, a phosphate, a phosphite, a sulfonate, a sulfone, a sulfoxide, and combinations thereof; wherein the method is characterized by having a difference between the reactor temperature and the dew point temperature of the recycle fluid of 12° C, or greater. Appeal Br. 13. The Examiner maintains the following grounds of rejection on appeal: Appeal 2020-001647 Application 12/941,440 3 (1) claims 1–7, 9, 10, 12–15, 17, 18, and 20–22 under 35 U.S.C. § 103(a) as unpatentable over Chen 2752 in view of Turkistani;3 and (2) claim 16 under 35 U.S.C. § 103(a) as unpatentable over Chen 275 in view of Turkistani, further in view of Sheard.4 We sustain the obviousness rejections on appeal for substantially the same reasons provided in the Final Office Action dated September 20, 2018 (“Final Act.”) and the Examiner’s Answer dated November 1, 2019 (“Ans.”). We add the following discussion for emphasis. B. DISCUSSION Claim 1 is directed to a method for polymerizing propylene. According to the claimed method, a mixed external electron donor system is introduced into a gas phase reactor with one or more Ziegler-Natta procatalyst compositions and a recycle fluid comprising propylene. Appeal Br. 13. The mixed external electron donor system comprises at least one selectivity control agent and at least one activity limiting agent. Appeal Br. 13. Claim 1 recites that “the method is characterized by having a difference between the reactor temperature and the dew point temperature of the recycle fluid of 12° C, or greater.” Appeal Br. 13; see also Spec. 2, ll. 5–7 (referring to “the difference between the temperature of the fluidized bed and the dew point temperature of the recycle gas” as the “‘bed minus dew temperature’”). The Examiner finds Chen 275 discloses a method for polymerizing propylene as recited in claim 1, with the exception of the claimed bed minus dew temperature. See Final Act. 2–3. The Appellant does not direct us to any error in 2 US 2007/0027275 A1, to Chen et al., published February 1, 2007 (“Chen 275”). 3 US 6,759,489 B1, to Turkistani, issued July 6, 2004 (“Turkistani”). 4 US 2009/0209706 A1, to Sheard et al., published August 20, 2009 (“Sheard”). Appeal 2020-001647 Application 12/941,440 4 that finding. See Appeal Br. 7. Rather, the Appellant argues that the Examiner reversibly erred in concluding that the claimed temperature difference would have been obvious to one of ordinary skill in the art based on the disclosure of Turkistani. See, e.g., Appeal Br. 8. Looking more closely at the obviousness rejection of claim 1, the Examiner finds that the polymerization process disclosed in Chen 275 “includes the use of condensing mode, wherein gaseous components including low boiling compounds are injected into the reactor in liquid form for purposes of heat removal.” Final Act. 3 (citing Chen 275, at ¶ 62). Turkistani describes a “condensing mode” as follows: In general, polymerization reactions are exothermic. Therefore, producing a polymer in a fluidized bed necessitates that the heat generated by the polymerization reaction be removed in order to keep the reaction temperature within the bed in a desirable range. Conventionally, the temperature of the reactor fluidized bed is controlled to an essentially isothermal level through continuously removing the heat of polymerization by circulating the gas exiting from the fluidized bed to a condenser/heat exchanger outside the reactor and recirculating the cooled gas stream back into the reactor. . . . [I]t has been recognized that the recycled stream need not be completely gaseous but can comprise both gas and liquid. In this process, fluid is formed by cooling the recycle stream below the dew point temperature,[5] thereby converting a portion of the gas into a liquid, and the cooled recycle stream is introduced into the fluidized 5 Turkistani discloses, Conventionally, the dew point or dew point temperature of a gas is the temperature at which that gas is saturated with respect to a condensable component. Thus, as a gas is cooled, the dew point temperature of that gas is that temperature at which liquid condensate begins to form in the gaseous portion. Turkistani, col. 17, ll. 17–22. Appeal 2020-001647 Application 12/941,440 5 bed polymerization reactor. This mode of operation is known in the art as a “condensing mode” or “condensed mode” process. Turkistani, col. 1, ll. 14–36 (emphasis added). The Examiner finds “Chen [275] does not provide further details regarding the recommended condensing mode operation, such as the dew point of the recycle fluid.” Final Act. 3. Nonetheless, the Examiner finds that “one of ordinary skill in the art would be motivated to consult similar olefin polymerization methods wherein effective parameters for condensing mode operation are described.” Final Act. 3. The Examiner finds Turkistani, like Chen 275, discloses a process for polymerizing propylene. Final Act. 3; Turkistani, col. 6, ll. 62–63 (disclosing that in one embodiment, “the method is directed to the polymerization of propylene”). The Examiner further finds that the method disclosed in Turkistani comprises introducing a recycle fluid comprising propylene into the gas phase reactor, said recycle fluid having a given dew point at the inlet to the gas phase reactor, wherein the difference between the reactor temperature and the dew point temperature of the recycle fluid is about 15°C or greater, in order to increase the cooling capacity of the reactor for the benefit of increasing the production rate of the polymerization reactor. Final Act. 3 (citations omitted); see also Turkistani, col. 17, ll. 44–53 (disclosing that the difference between the reactor bed temperature and the recycle stream dew point temperature may be “greater than or equal to about 5° C,” “greater than or equal to about 10° C,” and “greater than or equal to about 15° C”). The Examiner concludes that it would have been obvious to one of ordinary skill in the art to introduce a recycle fluid comprising propylene into a fluidized bed gas phase reactor operating in condensing mode as recommended in Chen [275], further operating at a difference between the reactor Appeal 2020-001647 Application 12/941,440 6 temperature and the dew point temperature of the recycle fluid of about 15°C or greater as recommended in Turkistani, in order to improve the cooling capacity of the reactor for the expected benefit of increasing the production rate of the polymerization, because each of Chen [275] and Turkistani recommend fluidized bed polymerization of propylene using condensing mode, and Turkistani provides further recommendations for selecting effective process parameters for the condensing mode system. Final Act. 3–4. The Appellant argues that the Examiner’s reliance on Turkistani in the obviousness rejections on appeal was erroneous. See, e.g., Appeal Br. 12. More specifically, the Appellant argues that one of ordinary skill in the art would have considered Chen 067,6 not Turkistani, the most relevant reference for determining the “bed minus dew temperature” in Chen 275’s process because, in contrast to Turkistani, Chen 067 uses catalyst systems of the type disclosed in Chen 275 and recited in the claims on appeal. Appeal Br. 7. That being said, the Appellant argues that Chen 067 would not have led one of ordinary skill in the art to the claimed invention because Chen 067 “discloses a bed minus dew temperature difference of 1–10°C or less,” which falls outside the claimed range of 12°C or greater. Appeal Br. 7–8. There is no dispute on this record that Turkistani’s polymerization process uses Ziegler-Natta catalysts. See Turkistani, col. 7, ll. 4–5, 21–22 (disclosing that “[t]he catalyst or catalysts used in the method of the invention are conventional” and “[i]n particular, the conventional catalyst can be of the Ziegler-Natta type”); Final Act. 4 (finding that Turkistani uses a Ziegler catalyst). Nonetheless, the Appellant argues that Turkistani “does not disclose or require use of internal or 6 US 2011/0152067 A1, to Chen et al., published June 23, 2011 (“Chen 067”). Appeal 2020-001647 Application 12/941,440 7 external electron donors [as recited in claim 1 on appeal] in connection with its generic reference to Ziegler-Natta catalysts.” Appeal Br. 10. The Appellant contends that internal and external electron donor components are “generally, if not universally, used in processes for polymerization of propylene.” Appeal Br. 10. However, the Appellant argues that Turkistani only exemplifies the polymerization and copolymerization of ethylene and Ziegler- Natta catalyst systems intended for ethylene polymerization do not employ those donors. Appeal Br. 10–11. The Appellant’s argument is not persuasive of reversible error. It is of no moment in the obviousness rejection on appeal that the examples in Turkistani are not directed to a process for polymerizing propylene. See In re Lamberti, 545 F.2d 747, 750 (CCPA 1976) (“all disclosures of the prior art, including unpreferred embodiments, must be considered”). Turkistani expressly discloses that in one embodiment of the invention, “the method is directed to the polymerization of propylene.” Turkistani, col. 6, ll. 62–63. Thus, based on the Appellant’s contention above, it appears that one of ordinary skill in the art would have understood that internal and external electron donor components are used in Turkistani’s process for polymerizing propylene. See Appeal Br. 10 (contending that internal and external electron donor components are “generally, if not universally, used in processes for polymerization of propylene”). Nonetheless, the Appellant does not direct us to any evidence establishing that the absence of internal and/or external electron donors in Turkistani’s process would have led one of ordinary skill in the art away from using Turkistani’s bed minus dew temperatures in Chen 275’s process. The mere fact that differences may exist between Chen 275’s and Turkistani’s catalyst systems does not suffice. See Ans. 8 (explaining that the Appellant’s assertion that “certain mixed electron Appeal 2020-001647 Application 12/941,440 8 donors [have] some bearing on selection of bed minus dew point temperature finds no support in the record, and the particulars of electron donors do[] not appear to have any relevance for selection of parameters for obtaining effective cooling by use of a condensing recycle system.”).7 In sum, a preponderance of the evidence of record establishes that one of ordinary skill in the art would have had a reasonable expectation of successfully polymerizing propylene according to Chen 275’s process wherein the bed minus dew temperature is 10°C as disclosed in Chen 067, or is greater than 12°C as taught by Turkistani.8 The obviousness rejections of the claims on appeal are sustained.9 C. CONCLUSION The Examiner’s decision is affirmed. 7 In the Reply Brief, the Appellant argues that Chen 067 discloses that “the use of specific external donors can limit the temperature rise in the reactor so as to prevent a ‘runaway’ temperature increase and its debilitating effects.” Reply Brief dated December 24, 2019, at 7. The Appellant does not provide a citation to Chen 067 supporting the Appellant’s argument. Moreover, the Appellant does not explain, in any detail, why this purported disclosure in Chen 067 would have led one of ordinary skill in the art away from a bed minus dew temperature within the ranges disclosed in Turkistani. 8 The Appellant contends that the claimed method can be carried out without fouling or static problems. Appeal Br. 3. Notably, Chen 275 discloses that the use of a selectivity control agent (SCA) and an activity limiting agent (ALA), as recited in Appellant’s claim 1, reduces softening or melting of polymer particles that leads to agglomerate formation and sheeting or fouling of the reactor. Chen 275, at ¶ 92. 9 The Appellant does not present arguments in support of the separate patentability of any of the dependent claims on appeal. Appeal 2020-001647 Application 12/941,440 9 In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–7, 9, 10, 12–15, 17, 18, 20–22 103(a) Chen 275, Turkistani 1–7, 9, 10, 12–15, 17, 18, 20–22 16 103(a) Chen 275, Turkistani, Sheard 16 Overall Outcome 1–7, 9, 10, 12–18, 20–22 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED Copy with citationCopy as parenthetical citation