Ex Parte Lu et alDownload PDFPatent Trial and Appeal BoardOct 21, 201311201713 (P.T.A.B. Oct. 21, 2013) 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. 11/201,713 08/11/2005 Jian Lu TH2224 (US) 6239 23632 7590 10/22/2013 SHELL OIL COMPANY P O BOX 2463 HOUSTON, TX 77252-2463 EXAMINER OH, TAYLOR V ART UNIT PAPER NUMBER 1622 MAIL DATE DELIVERY MODE 10/22/2013 PAPER 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. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE __________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte JIAN LU, DIEN HIEN DUONG, and NGA THIHUYEN VI __________ Appeal 2012-002969 Application 11/201,713 Technology Center 1600 __________ Before MELANIE L. McCOLLUM, JEFFREY N. FREDMAN, and ULRIKE W. JENKS, Administrative Patent Judges. FREDMAN, Administrative Patent Judge. DECISION ON APPEAL This is an appeal1 under 35 U.S.C. § 134 involving claims to a method of preparing a shaped epoxidation catalyst. The Examiner rejected the claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm. 1 Appellants identify the Real Party in Interest as Shell Oil Company (see App. Br. 2). Appeal 2012-002969 Application 11/201,713 2 Statement of the Case Background The Specification teaches “it remains highly desirable to improve the performance of olefin epoxidation catalysts, in respect of one or more of their activity, selectivity[,] and stability” (Spec. 3, ll. 25-28). “The invention relates to a method of preparing a shaped catalyst, and a shaped catalyst which is obtainable by the method” (Spec. 1, ll. 17-19). The Claims Claims 1-22, 25, and 26 are on appeal. Appellants do not present arguments for the separate patentability of claims other than representative claim 1. Thus, all claims stand or fall with the corresponding representative claim. 37 C.F.R. § 41.37(c)(l)(vii) (2011). Claim 1 reads as follows: 1. A method of preparing a shaped epoxidation catalyst, which method comprises moulding a dough into shaped particles and drying at least a portion of the shaped particles at a temperature below 1000 °C, wherein the dough comprises a support material, or a precursor thereof, a silver component, and a further element or compound thereof which acts as a promoter when the shaped catalyst is used as an epoxidation catalyst. The issue The Examiner rejected claims 1-22, 25, and 26 under 35 U.S.C. § 103(a) as obvious over Rubinstein2 and Notermann3 (Ans. 5-10). The Examiner finds that “Rubinstein expressly teaches the preparation of a paste comprising a uniform mixture of i) at least one alkaline earth metal carbonate support, ii) a liquid medium, iii) a silver bonding additive; 2 Rubinstein et al., WO 2004/030813 A1, published Apr. 15, 2004. 3 Notermann et al., US 4,994,587, issued Feb. 19, 1991. Appeal 2012-002969 Application 11/201,713 3 and iv) at least one extrusion aid” (Ans. 8). The Examiner finds that Notermann teaches “the silver catalytic system for epoxidation for alkenes employing low sodium catalyst supports. The silver is coated or deposited on a solid porous carrier by means of using a solubilizing agent solvent” (id.). The issue with respect to this rejection is: Does the evidence of record support the Examiner’s conclusion that Rubinstein and Notermann render claim 1 obvious? Findings of Fact 1. Rubinstein teaches a shaped silver bonded alkaline earth metal carbonate catalyst support may be prepared by: (a) preparing a paste comprising a uniform mixture of (i) calcium carbonate; (ii) at least one solvent; (iii) a silver oxalate ethylenediamine complex; and (iv) at least one extrusion aid; (b) forming a shaped particle from said paste; and (c) drying and calcining said shaped particle. (Rubinstein 5, ll. 10-14.) 2. Rubinstein teaches that the “support may be formed into shaped particles, for example, chunks, pieces, and the like. Preferably, for use in a tubular fixed bed reactor, they are formed into a rounded shape, for example in the form of spheres, pellets, cylinders, rings, wagon wheels, or tablets” (Rubinstein 4, ll. 28-31). 3. The Specification teaches that the “dough comprises a silver component. . . . [T]he silver component may comprise a compound of Appeal 2012-002969 Application 11/201,713 4 cationic silver. . . . Suitable cationic silver compounds are, for example . . . oxalates . . . or as an amine complex. . . . A preferred cationic silver compound is a silver/1,2-ethylene diamine oxalate complex” (Spec. 9, ll. 1- 28). 4. Rubinstein teaches that the “silver bonding additive may preferably be an aqueous silver oxalate amine solution having a concentration of silver from 15% to 33% by weight . . . . The preferred amine is ethylenediamine” (Rubinstein 4, ll. 3-6). 5. Rubinstein teaches that the “shaped support precursor is freed of uncombined and loosely held water by an initial, moderate heating, for example at a temperature in the range from 100 °C to 215 °C. Following this drying procedure, the calcination may be carried out in a dry or humid atmosphere at a temperature in the range from 200 °C to 950 °C” (Rubinstein 5, ll. 1-4). 6. The Specification teaches that the dough may comprise, as an additional component, a further element or compound thereof which acts as a promoter when the shaped catalyst is used as an epoxidation catalyst. Eligible further elements may be selected from the group of . . . Group IA metals . . . . Preferably the Group IA metals are selected from lithium, potassium, rubidium and cesium. (Spec. 10, ll. 1-11.) 7. Rubinstein teaches that “the support is impregnated with a liquid composition of compounds of silver, potassium, sodium and/or lithium and, if desirable with further compounds of, for example, one or more of rubidium and/or, cesium” (Rubinstein 6, ll. 1-4). Appeal 2012-002969 Application 11/201,713 5 8. The Specification teaches that the “support material for use in this invention may be natural or artificial inorganic particulate materials and they may include . . . alkaline earth metal carbonates, for example calcium carbonate” (Spec. 5, ll. 13-17). 9. Rubinstein teaches that: silver-amine-oxalate stock solution was prepared by the following procedure: 415 g of reagent-grade sodium hydroxide were dissolved in 2340 ml de-ionized water and the temperature was adjusted to 50 °C. 1699 g high purity “Spectropure” silver nitrate was dissolved in 2100 m1 de- ionized water and the temperature was adjusted to 50 °C. The sodium hydroxide solution was added slowly to the silver nitrate solution, with stirring, while maintaining a solution temperature of 50 °C. . . . 630 g of high-purity oxalic acid dihydrate were added in approximately 100 g increments. . . . The resulting solution contained approximately 27-33 %w silver. The above stock solution was used to prepare the silver doped calcium carbonate supports. (Rubinstein 10, ll. 10-30, Example 1A.) 10. Rubinstein teaches the preparation of the support itself, teaching that the: calcium carbonate supports . . . were prepared as follows: 100 parts by weight (pbw) calcium carbonate (CaCO3) mixed with 2 pbw of an organic extrusion aid such as starch. Sufficient water was added to make the mixture extrudable (45 pbw silver solution) and the resulting composition was mixed until homogeneous and extrudable. The resulting paste was forced through a 3 mm die. The resulting extrudate was dried overnight at 100 °C and then fired as follows: 1 hour ramp to 110 °C held for 1 hour, then 4 hour ramp to 240 °C and held for 1 hour and finally a 4 hour 10 ramp to 500 °C and held for 5 hours. Appeal 2012-002969 Application 11/201,713 6 (Rubinstein 11, ll. 3-10). 11. Rubinstein teaches that “the promoters may be impregnated in one or more separate steps, prior to silver impregnation, after silver impregnation or intermediate to separate silver impregnation steps” (Rubinstein 6, ll. 15-17). 12. Notermann teaches that the “silver may be introduced to the solvent or complexing/solubilizing agent as an oxide or a salt, such as nitrate or carboxylate, for example, an acetate, propionate, butyrate, oxalate, malonate, malate, maleate, lactate, citrate, phthalate, generally the silver salts of higher fatty acids, and the like” (Notermann, col. 15, ll. 54-60). 13. The Specification teaches that “[c]atalysts prepared in accordance with this invention can exhibit unexpectedly an improved performance in olefin epoxidation relative to catalysts prepared from the same materials, wherein however the silver component is deposited on an already shaped support” (Spec. 4, ll. 19-23). 14. Table I of the Specification is reproduced below: “The initial performance values for selectivity and temperature of each of the catalysts are reported in Table I” (Spec. 27, ll. 26-28). Appeal 2012-002969 Application 11/201,713 7 Principles of Law “The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). “If a person of ordinary skill can implement a predictable variation, § 103 likely bars its patentability.” Id. at 417. Analysis Rubinstein teaches a preparing “catalysts useful in olefin epoxidation processes” (Rubinstein 3, l. 5) where “the “support may be formed into shaped particles” (Rubinstein 4, ll. 28-31; FF 2) and where the “shaped support precursor is freed of uncombined and loosely held water by an initial, moderate heating, for example at a temperature in the range from 100 °C to 215 °C” (Rubinstein 5, ll. 1-3; FF 5). Rubinstein teaches an epoxidation catalyst composed of identical components as those taught in the instant Specification, including a support material, a silver component, and a “promoter compound” as required by claim 1. The Specification teaches that the “support material . . . may include . . . alkaline earth metal carbonates, for example calcium carbonate” (Spec. 5, ll. 13-17; FF 8). Rubinstein teaches an alkaline earth metal carbonate catalyst support which includes calcium carbonate (FF 1). The Specification teaches that the “dough comprises a silver component. . . . [T]he silver component may comprise a compound of cationic silver. . . . A preferred cationic silver compound is a silver/1,2- ethylene diamine oxalate complex” (Spec. 9, ll. 1-28; FF 3). Rubinstein Appeal 2012-002969 Application 11/201,713 8 teaches incorporation of silver compounds into the dough, including “a silver oxalate ethylenediamine complex” (Rubinstein 5, l. 12; FF 1, 4). The Specification teaches regarding the promoter element that “[e]ligible further elements may be selected from the group of . . . Group IA metals . . . . Most preferably the Group IA metal is lithium, potassium and/or cesium” (Spec. 10, ll. 1-13; FF 6). Rubinstein teaches that “the support is impregnated with a liquid composition of compounds of silver, potassium, sodium and/or lithium and, if desirable with further compounds of, for example, one or more of rubidium and/or, cesium” (Rubinstein 6, ll. 1-4; FF 7). Rubinstein’s method of preparing the epoxidation catalyst, while clearly incorporating the silver into the dough (FF 4), does not clearly indicate whether the promoter component is incorporated into the dough or whether the promoter component is added after the dough has been extruded (see FF 7). However, Rubinstein’s examples demonstrate the inclusion of sodium, a Group IA metal, into the silver-amine-oxalate stock solution, prior to formation of the dough or paste, where Rubinstein teaches that: silver-amine-oxalate stock solution was prepared by the following procedure: 415 g of reagent-grade sodium hydroxide were dissolved in 2340 ml de-ionized water and the temperature was adjusted to 50 °C. 1699 g high purity “Spectropure” silver nitrate was dissolved in 2100 m1 de- ionized water and the temperature was adjusted to 50 °C. The sodium hydroxide solution was added slowly to the silver nitrate solution, with stirring, while maintaining a solution temperature of 50 °C. . . . Appeal 2012-002969 Application 11/201,713 9 630 g of high-purity oxalic acid dihydrate were added in approximately 100 g increments. . . . The resulting solution contained approximately 27-33 %w silver. The above stock solution was used to prepare the silver doped calcium carbonate supports. (Rubinstein 10, ll. 10-30, Example 1A, FF 9.) Rubinstein then teaches the preparation of the support itself, teaching that the: calcium carbonate supports . . . were prepared as follows: 100 parts by weight (pbw) calcium carbonate (CaCO3) mixed with 2 pbw of an organic extrusion aid such as starch. Sufficient water was added to make the mixture extrudable (45 pbw silver solution) and the resulting composition was mixed until homogeneous and extrudable. The resulting paste was forced through a 3 mm die. The resulting extrudate was dried overnight at 100 °C and then fired as follows: 1 hour ramp to 110°C held for 1 hour, then 4 hour ramp to 240 °C and held for 1 hour and finally a 4 hour ramp to 500°C and held for 5 hours. (Rubinstein 11, ll. 3-10; Examples 1B-16, FF 10.) Thus, Rubinstein, in Examples 1A and 1B-16, prepares an epoxidation catalyst formed from a dough which comprises calcium carbonate, a support material (FF 1, 8, 10), a silver component, (FF 9-10), and sodium, a Group IA metal (FF 9-10). Rubinstein teaches that the resultant support was forced through a die and dried at temperatures less than 100 °C (FF 10). The process shown in Examples 1A and 1B-16 reasonably appears to satisfy each of the requirements of claim 1. Rubinstein’s examples 1A and 1B-16 therefore render obvious the method of claim 1. Moreover, Rubinstein suggests that “the promoters may be impregnated in one or more separate steps, prior to silver impregnation, after Appeal 2012-002969 Application 11/201,713 10 silver impregnation or intermediate to separate silver impregnation steps” (Rubinstein 6, ll. 15-17; FF 11). This is reasonably interpreted as a suggestion to incorporate the promoter into the dough, since Rubinstein exemplifes a method where the silver may be incorporated into the dough itself (FF 1, 9, 10). Appellants contend that the “method of impregnating a catalyst carrier with a silver solution is significantly different than a method in which the silver is mixed in the dough before it is formed into shaped particles and dried. There is nothing in the Rubinstein reference that teaches or suggests the claimed method” (App. Br. 3). Appellants contend that “[m]ixing the silver component and the promoter component with the support material to form a dough is a different process than forming a support and impregnating it with a silver component and a promoter component” (id. at 4). We are not persuaded. Rubinstein teaches and exemplifies methods where the silver is mixed in the dough before it is formed into shaped particles (FF 1, 9, 10) as discussed above. Further, Rubinstein teaches a method in which a promoter, sodium, a Group IA metal, is incorporated into the dough before it is formed into shaped particles (FF 9, 10). Finally, while impregnating may be different than incorporating the promoter into the dough, Rubinstein is reasonably interpreted as suggesting to the ordinary artisan that the promoters may be incorporated into the catalyst at a variety of different steps, which would have rendered incorporation into the dough obvious in light of Rubinstein’s express teaching that “the promoters may be impregnated in one or more separate Appeal 2012-002969 Application 11/201,713 11 steps, prior to silver impregnation, after silver impregnation or intermediate to separate silver impregnation steps” (Rubinstein 6, ll. 15-17; FF 11). Appellants contend that “the present invention can exhibit unexpectedly an improved performance in olefin epoxidation relative to catalysts prepared from the same materials, wherein the silver component is deposited on an already shaped support” (App. Br. 4). We are not persuaded. As an initial matter, Appellants did not compare their claimed method to the closest prior art, which would be Examples 1A and 1B-16 of Rubinstein, where sodium was present as a promoter and both silver and sodium were incorporated into the dough (FF 9-10), but rather compared a dough with the silver and promoters incorporated therein with shaped particles which were soaked in a silver and promoter solution (see Spec. 24, ll. 19-30). See In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed. Cir. 1991) (“[W]hen unexpected results are used as evidence of nonobviousness, the results must be shown to be unexpected compared with the closest prior art.”). In addition, claim 1 is broadly drawn to the use of any silver solution, while the asserted results are limited to the use of silver-1,2-ethylene diamine-oxalate with silver oxide. See In re Tiffin, 448 F.2d 791, 792 (CCPA 1971) (“objective evidence of non-obviousness must be commensurate in scope with the claims which the evidence is offered to support”). Lastly, as we review the results, themselves, we agree with the Examiner that the differences shown are minimal (see Ans. 14). Control Example B actually shows a higher selectivity than inventive Examples C Appeal 2012-002969 Application 11/201,713 12 and D, and a very similar initial activity temperature to inventive Example D (FF 14). Even the selectivity after 0.5 kTon/m3 of control Example B at 86.6 differs from inventive example 87.3 by less than 1%. There is no explanation why results with such minimal differences from the control examples are unexpected, since the ordinary artisan would have reasonably expected some differences to occur using any compositions prepared by slightly different processes, when testing was performed. See In re Klosak, 455 F.2d 1077, 1080 (CCPA 1972) (“it is not enough to show that results are obtained which differ from those obtained in the prior art: that difference must be shown to be an unexpected difference”). Appellants have not made this showing, since there is no explanation why the small differences between control Example B and Examples A and C-F would have been unexpected differences. Conclusion of Law The evidence of record supports the Examiner’s conclusion that Rubinstein and Notermann render claim 1 obvious. SUMMARY In summary, we affirm the rejection of claim 1 under 35 U.S.C. § 103(a) as obvious over Rubinstein and Notermann. Pursuant to 37 C.F.R. § 41.37(c)(1), we also affirm the rejection of claims 2-22, 25, and 26, as these claims were not argued separately. Appeal 2012-002969 Application 11/201,713 13 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). 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