Ex Parte Schmidt et al

Patent Trial and Appeal BoardAug 8, 2017

13693281 (P.T.A.B. Aug. 8, 2017)

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. 13/693,281 12/04/2012 Andrea SCHMIDT 408537US99 1475 22850 7590 08/10/2017 OBLON, MCCLELLAND, MAIER & NEUSTADT, L.L.P. 1940 DUKE STREET ALEXANDRIA, VA 22314 EXAMINER MURESAN, ANA Z ART UNIT PAPER NUMBER 1671 NOTIFICATION DATE DELIVERY MODE 08/10/2017 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): patentdocket @ oblon. com oblonpat @ oblon. com tfarrell@oblon.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte ANDREA SCHMIDT, MICHAEL BOCK, RODERICH ROETTGER, ROBERT BAUMANN, and AXEL FRANZKE Appeal 2015-007508 Application 13/693,2811 Technology Center 1600 Before DONALD E. ADAMS, FRANCISCO C. PRATS, and DAVID COTTA, Administrative Patent Judges. COTTA, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134 involving claims to a process for obtaining a dialkyl carbonate and an alkylene glycol. The Examiner rejected the claims on appeal as obvious under 35 U.S.C. § 103(a). We reverse. STATEMENT OF THE CASE Claims 1—20 are on appeal. Claim 1 is illustrative and reads as follows: 1 According to Appellants, the real party in interest is BASF SE. App. Br. 1. Appeal 2015-007508 Application 13/693,281 1. A process for obtaining a dialkyl carbonate and an alkylene glycol from a stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol, comprising the following steps: (a) distillatively removing a stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope from the stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol in a first distillation stage (1), (b) separating the stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope into a first crude product stream (27) comprising dialkyl carbonate and a second crude product stream (29) comprising alkylene glycol in an apparatus for phase separation (25). App. Br. 9. The following grounds of rejection by the Examiner are before us on review: Claims 1—14, 19 and 20 were rejected under 35 U.S.C. § 103(a) as obvious over Tatsuki.2 Claims 1—3 and 13—20 were rejected under 35 U.S.C. § 103(a) as obvious over Buchanan.3 OBVIOUSNESS OVER TATSUKI Tatsuki discloses a process for continuously and simultaneously producing dialkyl carbonate and glycol. Tatsuki Abstract. Tatsuki’s process involves the following steps: 1) alkylene carbonate and alcohol are fed into a reactor with a heterogeneous catalyst so as to conduct a transesterification reaction, 2) liquid from the reactor is discharged into a distillation column to be separated into a low-boiling fraction containing alcohol and dialkyl 2 Tatsuki et al., JP 2003-081893, published Mar. 19, 2003 (“Tatsuki”). Citations to Tatsuki are to a machine translation provided by the Examiner. 3 Buchanan et al., US Patent Publication No. 2003/0078448 Al, published Apr. 24, 2003 (“Buchanan”). 2 Appeal 2015-007508 Application 13/693,281 carbonate and a high-boiling fraction containing glycol and alkylene carbonate, 3) dialkyl carbonate is separated from the low-boiling fraction, and 4) glycol is separated from the high-boiling fraction and alkylene carbonate is returned to the reactor used in step 1. Id. The process used in Tatsuki is summarized in the below schematic. diaJky! carbonate alkylene carbonate alkylene glycol alcohol alcohol alkylene glycol alkylene carbonate The above schematic is a high-level summary provided by the Appellants of Tatsuki’s process. See App. Br. 4. In finding claims 1—14, 19 and 20 obvious over Tatsuki, the Examiner acknowledged that Tatsuki did not “explicitly disclos[e] removing dialkyl carbonate and alkylene glycol as [a] heteroazeotrope” from the stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol. Ans. 7. The Examiner reasoned, however, that because Tatsuki used the same starting materials (dialkyl carbonate, alkylene carbonate, alkylene glycol and an alchohol), it would inherently produce a dialkyl carbonate/glycol mixture with heteroazeotropic characteristics as recited in the present claims. Id. Based on these teachings, and the fact that the claims recite the term “comprising,” thus permitting “additional components such as alcohol in the dialkyl stream or alkylene carbonate in the alkylene glycol stream” {id. at 15—16), the Examiner concluded that the claimed process would have been obvious. The Examiner explained: The prior art as a whole, as taught by the general disclosure of [Tatsuki,] indicates that the method for producing dialkyl carbonate and a glycol by reaction of alkylene carbonate and alcohol under heterogeneous catalysis can be optimized by 3 Appeal 2015-007508 Application 13/693,281 reducing the energy necessary for separating and recycling the unreacted alcohol which requires carrying out the ester exchange reaction continuously by recycling the alkylene carbonate to the reactor and to produce simultaneously dialkyl carbonate and glycol (see paragraphs [0012] and [0013]). Given the disclosure in the prior art, and the art recognized problem o[f] optimizing the separation of the reaction mixture in [] the distillation column, [] optimizing the separation of the reaction mixture and the distillation apparatus to arrive at the instant invention would have been routine to the skilled artisan and is considered to be prima facie obvious. Ans. 8—9. Appellants argue, inter alia, that Tatsuki discloses a different process than is recited in the present claims. App. Br. 4. Whereas Tatsuki distills dialkyl carbonate and alcohol from the starting materials, the claimed method distills dialkyl carbonate and alkyelene glycol from the starting materials. Id. Appellants argue that the examples provided in Tatsuki provide no indication that a heteroazeotrope of dialkyl carbonate and alkylene glycol is formed (App. Br. 5—6), and, in fact, provide teachings that suggest that Tatsuki’s low-boiling fraction does not include a heteroazeotrope. Reply Br. 2. As stated in In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992): “[T]he examiner bears the initial burden ... of presenting a prima facie case of unpatentability.” Appellants have persuaded us that the Examiner has not carried the burden of establishing that the claimed invention would have been obvious over Tatsuki. Tatsuki discloses that when dialkyl carbonate is distilled from the starting materials in the low-boiling fraction, alkylene glycol remains behind in the high boiling fraction. Tatsuki Abstract. The claims require “distillatively removing a stream (5) comprising dialkyl carbonate and 4 Appeal 2015-007508 Application 13/693,281 alkylene glycol.” While the Examiner is correct that the claims permit additional components — like alcohol — in the stream distilled from the starting materials (i.e. Tatsuki’s low-boiling fraction), the distilled stream must include both dialkyl carbonate and alyklene glycol. Nothing in Tatsuki suggests that the low-boiling fraction contains glycol. The Examiner finds that because Tatsuki uses the same starting materials as the claimed process, it would inherently produce a heteroazeotrope of dialkyl carbonate and alkylene glycol. Ans. 7. We are not persuaded. Tatsuki does not identify glycol as being present in the low- boiling fraction. In contrast, Tatsuki expressly states that the high-boiling fraction contains alkylene glycol. This strongly suggests that alkylene glycol is not present in the low-boiling fraction.4 If alkylene glycol were present in the low boiling fraction, one would expect Tatsuki to have mentioned it, particularly given that a stated objective of Tatsuki’s process is to produce glycol. See Tatsuki Abstract. As the Examiner has not persuasively demonstrated that the low-boiling fraction in Tatsuki would necessarily contain alkylene glycol, we reverse the Examiner’s rejection of claims 1—14, 19, and 20 as obvious over Tatsuki. 4 Appellants argue that “no heteroazeotrope of dialkylcarbonate and alkylene glycol is formed” when using methanol or ethanol as the alcohol. App. Br. 5—6. This is consistent with our interpretation of Tatsuki as suggesting that the low-boiling fraction does not contain glycol; however, we do not rely on it in reaching our decision because it is not supported by evidence of record. See, Johnston v. IVAC Corp., 885 F.2d 1574, 1581 (Fed. Cir. 1989) (“Attorneys’ argument is no substitute for evidence.”); In re Pearson, 494 F.2d 1399, 1405 (CCPA 1974). 5 Appeal 2015-007508 Application 13/693,281 OBVIOUSNESS OVER BUCHANAN Buchanan discloses a “process for the production of a dialkyl carbonate and a diol from a cyclic carbonate and an aliphatic monohydric alcohol.” Buchanan Abstract. In Buchanan’s process “cyclic carbonate and aliphatic monohydric alcohol are reacted in the presence of a transesterification catalyst to form a crude product stream which contains a dialkyl carbonate, a diol, a hydroxy alkyl carbonate . . . unreacted aliphatic monohydric alcohol and unreacted cyclic carbonate.” Id. The crude product stream is fed into a distillation column, where “an overhead product stream enriched in the dialkyl carbonate, alcohol and organic oxygenates is removed via line 6 and a bottoms product stream enriched in the diol, cyclic carbonate, hydroxy alkyl carbonate and polyglycols is removed via line 7.” Id. at 163. The process used in Buchanan is summarized in the below schematic. The above schematic is a high-level summary provided by the Appellants of Buchanan’s process. See App. Br. 6. The Examiner’s reasoning in finding claims 1—3 and 13—20 obvious over Buchanan is similar to that used to find claims 1—14, 19, and 20 obvious over Tatsuki. In finding claims 1—3 and 13—20 obvious over Buchanan, the Examiner acknowledged that Buchanan “does not specify the heteroazeotrope dialkyl carbonate/glycol during separation.” Ans. 12. The Examiner reasoned, however, that “the '448 reference discloses the process dialky! carbonate alkyiene carbonate — alkvlene glycol alcohol hvdroxyalkyl carbonate alkvlene glycol alkvlene carbonate hydroxyatkyl carbonate 6 Appeal 2015-007508 Application 13/693,281 for making dialkyl carbonates prepared from the same components as claimed by applicants” and would therefore inherently produce “dialkyl carbonate and glycol products similarly as instantly claimed products, and would exhibit similar heteroazeoptropic characteristics.” Id. Based on these teachings, and the fact that the claims recite the term “comprising,” thus permitting “additional components of the stream” {id. at 19), the Examiner concluded that the claimed process would have been obvious. The Examiner explained: since the prior art process teaches reactive distillation, the starting material present for the initial reaction is necessarily present in the same column as the distillation (or purification), such that the distillation would.. .result in separation of the dialkyl carbonate and alkylene glycol from the crude reaction mixture in a similar manner as claimed in the instant process when the starting raw material compounds referenced by the '488 publication are used. Accordingly, by following the guidance within the prior art, the skilled artisan would have been capable of preparing dialkyl carbonate and alkylene glycol within those suggested by the prior art where said product are separated by distillation liquid-liquid extraction from the crude reaction mixture are obtained. Ans. 20. Appellants argue, inter alia, that Buchanan discloses a different process than is recited in the present claims. App. Br. 6. Whereas Buchanan distills dialkyl carbonate and alcohol from the starting materials, the claimed method distills dialkyl carbonate and alkyelene glycol from the starting materials. Appellants argue that the examples provided in Buchanan provide no indication that a heteroazeotrope of dialkyl carbonate and alkylene glycol is formed (App. Br 6), and, in fact, provide teachings that suggest that 7 Appeal 2015-007508 Application 13/693,281 Buchanan’s overhead product stream does not include a heteroazeotrope. Reply Br. 2—3. As discussed above, “[T]he examiner bears the initial burden ... of presenting a prima facie case of unpatentability.” In re Oetiker, 977 F.2d at 1445. Appellants have persuaded us that the Examiner has not carried the burden of establishing that the claimed invention would have been obvious over Buchanan. Buchanan discloses that when dialkyl carbonate is distilled from the starting materials in the “overhead product stream,” diol (glycol) is removed in a “bottoms product stream.” Buchanan | 63. The claims require “distillatively removing a stream (5) comprising dialkyl carbonate and alkylene glycol.” While the Examiner is correct that the claims permit additional components — like alcohol — in the stream distilled from the starting materials (i.e. overhead product stream), the distilled stream must include both dialkyl carbonate and alyklene glycol. Nothing in Buchanan suggests that the overhead product stream contains glycol. The Examiner finds that because Buchanan uses the same starting materials as the claimed process, it would inherently produce a heteroazeotrope of dialkyl carbonate and glycol. Ans. 19. We are not persuaded. Buchanan does not identify glycol as being present in the overhead product stream. In contrast, Buchanan expressly states that the bottoms product stream contains diol. This strongly suggests that diol is not present in the overhead product stream. If diol were present in the overhead product stream, one would expect Buchanan to have mentioned it, particularly given Buchanan identifies a need for a process that produces dialkyl carbonate and diol. See Buchanan 110. As the Examiner has not persuasively demonstrated that the overhead product stream fraction in 8 Appeal 2015-007508 Application 13/693,281 Buchanan would necessarily contain alkylene glycol, we reverse the Examiner’s rejection of claims 1—3 and 13—20 as obvious over Buchanan. SUMMARY For the reasons set forth herein, we reverse the Examiner’s rejection of claims 1—14, 19, and 20 as obvious over Tatsuki and the Examiner’s rejection of claims 1—3 and 13—20 as obvious over Buchanan. REVERSED 9