DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Status
The claims were not amended.
Response to Arguments
Applicant's arguments filed 5/1/26 have been fully considered but they are not persuasive.
The remarks on page 3, argues the following:
Applicant respectfully disagrees with the Examiner's contention aluminum-pair concentration is a "result-effective variable" subject to routine optimization because the prior art did not teach that teach aluminum-pair concentration could be optimized to improve para-xylene selectivity. Applicant respectfully submits that a variable can be optimized for purposes of obviousness only when the prior art recognizes that the variable affects the relevant result. MPEP §2144.05.III.C. The purpose of Nimlos is to understand and control aluminum sitting through structure-directing agents and to characterize resulting materials. Nimlos does not investigate toluene methylation, para-xylene production, para-xylene selectivity, or any alkylation process involving oxygenates and toluene, and therefore does not teach a relationship exists between the disclosed Al-pair populations and para-xylene production performance.
Obviousness requires more than a generalized possibility and instead requires a reasoned basis for expecting that the particular feature would affect the particular property of interest in the claimed process. Zeolites are used in an extraordinarily broad range of catalytic applications, many of which involve different active sites, mechanisms, rate- determining steps, and selectivity controls. The mere statement in Nimlos that Al arrangements may affect "catalytic and adsorption properties" does not provide a specific teaching that Al-pair concentration affects the para-xylene synthesis.
Neither Chen nor Nimlos recognizes proximate framework aluminum concentration as affecting para-xylene production, para-xylene selectivity, or xylene distribution. Nimlos merely teaches methods for synthesizing and characterizing MFI zeolites having different proximate framework aluminum population and reports those values as structural characteristics. Chen provides an explanation for para-xylene selectivity based on diffusion, not aluminum pairing. Therefore, the Examiner has not established that proximate framework aluminum is a recognized result-effective variable for the claimed para-xylene process, and therefore, a prima facie case of obviousness cannot be established based on the cited references.
Furthermore, per MPEP $2143.02.1, obviousness requires more than a mere ability to combine references. Even where references can be physically combined, the Examiner must establish that a person of ordinary skill in the art would have had a reasonable expectation that the proposed modification would achieve the claimed result. As already submitted, neither Chen nor Nimlos recognizes proximate framework aluminum concentration as affecting para-xylene production. Furthermore, Chen and Nimlos proceed from fundamentally different technical premises. Chen teaches that para-selectivity is governed by diffusion and crystal morphology, whereas Nimlos merely teaches synthesis and characterization of different Al-pair populations. The Office Action does not establish why a person of ordinary skill in the art would possess a reasonable expectation that modifying proximate framework aluminum to a concentration of less than 18% would favorably affect para-xylene production. Zhou, Gu and Helton also do not remedy the deficiencies of Chen and Nimlos.
The remarks are respectfully not persuasive. Nimlos explains that “Recently, we reported that the molecular structure and cationic charge density of the SDAs used to crystallize CHA zeolites influences Al proximity in 6-MRs in a predictable and systematic manner” (page 9278, right col, para. 1). Nimlos then states that “We then exercise this quantitative characterization tool on a suite of MFI zeolite samples crystallized using TPA+ as the organic SDA in addition to samples crystallized with TPA+ or with other charge-neutral organic SDAs in combination with higher charge density inorganic SDAs to determine their influence on the formation of Al-Al pairs” (page 9278, right col, last para). Therefore, in tests, Nimlos shows that when the SDAs of scheme 1 are tested using these different SDAs, the fraction of Al in pairs varied (see table 1).
In some instances, use of TMPA and DABCO, as well as PETP produces a zeolite with Al fraction pairs that are less than 18% in the zeolite.
Applicant argues that the Al pairs % in the zeolite are not optimized based on the resultant use, which is para-xylene production performance. This is agreed. Nimlos was relied upon to show that the Al pair % is an optimizable feature and that one of ordinary skill in the art would determine based on the desired use through routine experimentation
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, USPQ 233 (CCPA 1955).
Next, the arguments contend the following:
Applicant has discovered that framework aluminum proximity is directly correlated with para-xylene-selective aromatic methylation. The examples demonstrate a shift in intrinsic reaction chemistry; wherein low proximate framework aluminum MFI materials produce para-xylene as the predominant xylene isomer while conventional MFI materials predominantly produce ortho-xylene. The application additionally teaches that highly dispersed framework aluminum suppresses polymethylbenzene formation thereby improving methanol utilization and promoting selective aromatic methylation. Accordingly, it is the instant application that presents not only the discovery of the relevance of framework aluminum proximity to para-xylene production but also quantified a practical threshold (<18%) that is absent from both Chen and Nimlos. See paragraphs [0028]-[0030] and [0058]-[0060] of Applicants' specification.
The remarks are respectfully not persuasive. The arguments cite to a correlation between aluminum pairs and para-xylene selective aromatic methylation, but the remarks generally cite to paragraphs 28-30 of the specification for this superior performance. Paragraph 28 states that how the MFI is synthesized, impacts the acid sites and Al pairs and that the number of Al pairs produces is partly determined by the SDA employed (para. 28). As a result, paragraph 30 explains that use of a TPA OSD is not desirable.
Nimlos explains that based on their analysis that shows that different SDAs produce zeolites with different Al pair structures, one of ordinary skill in the art should “. . . develop synthetic strategies that can predictably vary their framework Al arrangement and catalytic and adsorption properties in turn. . . “ (abstract). Therefore, Nimlos explains that one of skill in the art should use their data to define the optimum value of Al pairs for their particular use of the zeolite product made.
Next, the remarks argues the following:
Additionally, claims 17 and 19 recite "a SiO2/Al₂O₃ ratio of from about 100 to about 500". Chen does not teach or suggest a SiO2/Al₂O₃ ratio of from about 100 to about 500. The Examiner has acknowledged the same in Pages 12 and 16 of the Office Action. However, the Examiner has relied upon Zhou to obviate the above limitation.
Applicant respectfully submits that Zhou is not directed toward the claimed para-xylene production process. The claims are directed to the methylation of an aromatic feedstock comprising toluene with an oxygenate feedstock in the presence of a specifically defined MFI catalyst. In contrast, Zhou relates to an aromatization catalyst and an isomerization catalyst to convert light hydrocarbons, not oxygenates, and aromatic feeds into aromatic products. Zhou does not disclose or suggest methylation of toluene or any oxygenate feedstock as recited in the claims. Accordingly, Zhou addresses a fundamentally different reaction chemistry and cannot supply a motivation regarding catalyst selection for aromatic methylation to para-xylene.
The remarks are respectfully not persuasive. Claims 17 and 19 state in the preamble and the body of the claim that their claims are processes used for “the production of para-xylene”. Zhou describes a method of making a zeolite for the production of p-xylene (abstract). Applicant’s arguments describe features narrower than the claims.
Zhou explains that their catalyst composition includes two catalysts, one is used upstream of the other (see page 3, para. 3). However, both catalysts are used to make a p-xylene product. The zeolite used in Zhou is a ZSM-5 zeolite used to ultimately make a p-xylene product.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 2, 8, 9, 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen “Reactions of Mixture of Toluene and Methanol over ZSM-5” and in view of Nimlos, Claire et al. “Experimental and Theoretical Assessments of Aluminum Proximity in MFI Zeolites and its Alteration by Organic and Inorganic Structure-Directing Agents”, submitted in IDS on 6/17/23.
As to Claims 1, 2 and 10, Chen describes a method of reacting a mixture of toluene and methanol over a ZSM-5 sieve (title) produce xylene isomers (page 18, right col, last para), such as p-xylene (page 19, left col, line 8). Chen explains that the para-version of the xylene isomers can be improved by optimizing certain features, such as crystal size (page 19, right col, lines 12-15). The ZSM-5 has a SiO2/Al2O3 ratio of 70 (see page 17, right col, “Experimental”, para. 1). ZSM-5 zeolites have an MFI topology. The ZSM-5 is calcined and ion-exchanged (see page 17, “Experimental”, para. 1). ZSM-5 zeolites have an MFI structure.
Chen does not teach that the ZSM-5 has a population of proximate framework aluminum sites characterized by less than about 18% of proximate aluminum sites characterized by a cobalt titration technique.
As to this feature, Nimlos describes an MFI zeolite and assesses the aluminum proximity in these zeolites based on the organic and inorganic structure-directing agents (SDA) used to make these compounds (title). Nimlos explains that the type of SDA used, influences the siting and the arrangement of Al in the zeolite frameworks (abstract). Nimlos describes their use of cobalt titration used to quantifying Al-Al site pairs in MFI zeolites (abstract). In their tests, Nimlos shows the fraction of Al in pairs to range from 0.06 to 0.14% when using DABCO or that it can range from 34-2% when using TPA (see table 1).
After formation of the product, the zeolite made is heated at elevated temperature of about 853 K (see page 9279, right col, para. 3). This can be considered a calcination temperature. The product made is then ion-exchanged (page 9279, right col, section 2.2, para. 1) . The products made with varying Al arrangements can vary the zeolite catalytic and adsorption properties (abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the use of SDA and then quantified using cobalt titration in order to obtain the desired Al pairs from 0.6% to 14%, as taught by Nimlos for use with Chen because this is an optimizable feature, which can be used to adjust the catalytic and adsorption properties.
It would have been obvious to one having ordinary skill in the art to have determined the optimum value of a cause effective variable such as aluminum pairs through routine experimentation in the absence of a showing of criticality. In re Woodruff, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Zhou (CN 112028730).
Chen describes in their example that the SiO2/Al2O3 ratio is about 70 (see “experimental” para. 1).
It has been held that a prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985). See MPEP 2144.05.
Alternatively, the claimed range is known, as described by Zhou.
Zhou describes a ZSM-5 molecular sieve (title) that is useable for in producing p-xylene (abstract). The catalyst is a metal-modified ZSM-5 molecular sieve, which has a SiO2/Al2O3 ratio of 50-100 (see page 4, para. 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a ZSM-5 molecular sieve that has a SiO2/Al2O3 range of 50-100, as taught by Zhou for use with the ZSM-5 of Chen and Nimlos because Zhou teaches that a broader SiO2/Al2O3 range of 50-100 is effective for use in zeolite catalysts in making p-xylene.
As to Claims 8 and 9, the range for phosphorous and calcium or magnesium can be zero. Therefore, since in some embodiments, Chen and Nimlos do not describe use of these, the references meet these claims.
Claim(s) 5, 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Gu (CN 113979446).
The references do not teach that the MFI contains one of the metals in Claim 5 or in the ratio of Claim 6.
Gu describes a molecular sieve that has a ZSM-5 framework (page 3, last 3 lines) used for methylating alcohol (abstract), which can produce a p-xylene (see Background, para. 1). The molecular sieve can be a boron-containing molecular sieve (title). Gu explains in the background that ZSM-5 molecular sieved used in toluene methanol allylation reaction to make p-xylene has limitations (Background, para. 1, 2). As a solution to this, use of a boron-containing molecular sieve improves the ZSM-5 and also improves the xylene selectivity (Background, para. 3). In their invention, Gu explains that their preferred ratio of SiO2/B2O3 can be 12-200 (page 4, lines 30-31).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include boron in the MFI in an amount of SiO2/B2O3 of 12-200, as taught by Gu for use with the ZSM-5 of Chen and Nimlos because this improves upon the use of ZSM-5 for making p-xylene with toluene and methanol.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Helton (US Pub.: 2014/0213840).
The references do not teach that the MFI zeolite is in the catalyst in an amount of 5-15wt%.
Helton describes a process for producing para-xylene using toluene and methanol in the presence of a catalyst (abstract). The catalyst can include 5-15wt% of a ZSM-5 molecular sieve (abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a ZSM-5 catalyst in an amount of 5-15wt%, as taught by Helton for use with the process of Chen and Nimlos because this amount is effective in producing para-xylene from toluene and methanol.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Iaccino (US Pub.: 2013/0296624).
Iaccino describes a process for the production of xylenes (title), particularly para-xylene (para. 4) made from toluene and methanol (para. 4). The process employs a first catalyst that contains about 50wt% of ZSM-5 sieve (para. 77).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a ZSM-5 sieve in an amount of 50wt%, as taught by Iaccino for use with the catalyst of Chen and Nimlos because this amount is effective in making para-xylene from toluene and methanol.
Claim(s) 11, 13, 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Bulin (CN 1759081).
The references do not describe the reaction conditions.
Bulin describes a method for preparing p-xylene (title) made by combining toluene and methanol in a reaction mixture with a ZSM-5 zeolite material (abstract). The ratio of toluene to methanol is about 8 (page 3, last para). The reaction operates at a temperature of about 440 degrees C (page 4, para. 6) and is fed using a nitrogen flow and a hydrogen flow (page 4, para. 6). As to the ratio of toluene to methanol, Bulin teaches that the ratio can range from 4/1 to 1.3/1 (page 6, para. 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the reaction at a temperature at about 440 degrees C, as taught by Bulin for use with the process of Chen and Nimlos because this temperature range is known to be effective in producing para-xylene.
As to Claim 13, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a ratio of toluene to methanol in an amount of 4/1 to 1.3/1, as taught by Bulin for use with the process of Chen and Nimlos because this ratio is known to be effective in generating para-xylene product.
As to Claim 15, Bulin teaches use of hydrogen diluent (see above). it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a hydrogen diluent, as taught by Bulin for use with the process of Chen and Nimlos because adding this is a known and effective method of producing a para-xylene product.
Claim(s) 12, 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen and Nimlos as applied to claim 1 above, and further in view of Benedict (US Pub.: 2020/0308087).
The references do not describe the features of Claims 12 and 14.
Benedict describes a para-xylene product system (title) that can use a ZSM-5 catalyst (para. 31). The reference explains that the production method can include heating the reaction to a range of 220-480 degrees C and can be compressed at a pressure of 446kPa to 3500 kPa at a WHSV from 0.5 to 50hr-1 (para. 77).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the reaction at a pressure of 446kPa to 3500 kPa and a WHSV of 0.5 to 50hr-1, as taught by Benedict for use with the process of Chen and Nimlos because these conditions are known to be effective in generating para-xylene when using a catalyst.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen, Nimlos and Benedict as applied to claim 14 above, and further in view of Bulin (CN 1759081).
The references do not describe the reaction conditions.
Bulin describes a method for preparing p-xylene (title) made by combining toluene and methanol in a reaction mixture with a ZSM-5 zeolite material (abstract). The ratio of toluene to methanol is about 8 (page 3, last para). The reaction operates at a temperature of about 440 degrees C (page 4, para. 6) and is fed using a nitrogen flow and a hydrogen flow (page 4, para. 6). As to the ratio of toluene to methanol, Bulin teaches that the ratio can range from 4/1 to 1.3/1 (page 6, para. 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a ratio of toluene to methanol in an amount of 4/1 to 1.3/1, as taught by Bulin for use with the process of Chen, Nimlos and Benedict because this ratio is known to be effective in generating para-xylene product.
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen “Reactions of Mixture of Toluene and Methanol over ZSM-5” and in view of Nimlos, Claire et al. “Experimental and Theoretical Assessments of Aluminum Proximity in MFI Zeolites and its Alteration by Organic and Inorganic Structure-Directing Agents”, submitted in IDS on 6/17/23 and further in view of Zhou (CN 112028730) and in view of Gu (CN 113979446).
Chen describes a method of reacting a mixture of toluene and methanol over a ZSM-5 sieve (title) produce xylene isomers (page 18, right col, last para), such as p-xylene (page 19, left col, line 8). Chen explains that the para-version of the xylene isomers can be improved by optimizing certain features, such as crystal size (page 19, right col, lines 12-15). The ZSM-5 has a SiO2/Al2O3 ratio of 70 (see page 17, right col, “Experimental”, para. 1). ZSM-5 zeolites have an MFI topology. The ZSM-5 is calcined and ion-exchanged (see page 17, “Experimental”, para. 1). ZSM-5 zeolites have an MFI structure.
Chen does not teach that the ZSM-5 has a population of proximate framework aluminum sites characterized by less than about 18% of proximate aluminum sites characterized by a cobalt titration technique.
As to this feature, Nimlos describes an MFI zeolite and assesses the aluminum proximity in these zeolites based on the organic and inorganic structure-directing agents (SDA) used to make these compounds (title). Nimlos explains that the type of SDA used, influences the siting and the arrangement of Al in the zeolite frameworks (abstract). Nimlos describes their use of cobalt titration used to quantifying Al-Al site pairs in MFI zeolites (abstract). In their tests, Nimlos shows the fraction of Al in pairs to range from 0.06 to 0.14% when using DABCO or that it can range from 34-2% when using TPA (see table 1).
After formation of the product, the zeolite made is heated at elevated temperature of about 853 K (see page 9279, right col, para. 3). This can be considered a calcination temperature. The product made is then ion-exchanged (page 9279, right col, section 2.2, para. 1) . The products made with varying Al arrangements can vary the zeolite catalytic and adsorption properties (abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the use of SDA and then quantified using cobalt titration in order to obtain the desired Al pairs from 0.6% to 14%, as taught by Nimlos for use with Chen because this is an optimizable feature, which can be used to adjust the catalytic and adsorption properties.
It would have been obvious to one having ordinary skill in the art to have determined the optimum value of a cause effective variable such as aluminum pairs through routine experimentation in the absence of a showing of criticality. In re Woodruff, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
As to the SiO2/Al2O3 ratio, Zhou describes a ZSM-5 molecular sieve (title) that is useable for in producing p-xylene (abstract). The catalyst is a metal-modified ZSM-5 molecular sieve, which has a SiO2/Al2O3 ratio of 50-100 (see page 4, para. 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a ZSM-5 molecular sieve that has a SiO2/Al2O3 range of 50-100, as taught by Zhou for use with the ZSM-5 of Chen and Nimlos because Zhou teaches that a broader SiO2/Al2O3 range of 50-100 is effective for use in zeolite catalysts in making p-xylene.
The references do not teach that the MFI contains one of the metals in the claim or the ratio of that metal to Si.
Gu describes a molecular sieve that has a ZSM-5 framework (page 3, last 3 lines) used for methylating alcohol (abstract), which can produce a p-xylene (see Background, para. 1). The molecular sieve can be a boron-containing molecular sieve (title). Gu explains in the background that ZSM-5 molecular sieved used in toluene methanol allylation reaction to make p-xylene has limitations (Background, para. 1, 2). As a solution to this, use of a boron-containing molecular sieve improves the ZSM-5 and also improves the xylene selectivity (Background, para. 3). In their invention, Gu explains that their preferred ratio of SiO2/B2O3 can be 12-200 (page 4, lines 30-31).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include boron in the MFI in an amount of SiO2/B2O3 of 12-200, as taught by Gu for use with the ZSM-5 of Chen and Nimlos because this improves upon the use of ZSM-5 for making p-xylene with toluene and methanol.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen, Nimlos, Zhou and Gu as applied to claim 17 above, and further in view of Benedict (US Pub.: 2020/0308087) and in view of Bulin (CN 1759081).
Chen, Nimlos, Zhou and Gu do not teach the process features for making para-xylene, as described by Claim 18.
As to the WHSV and pressure, Benedict describes a para-xylene product system (title) that can use a ZSM-5 catalyst (para. 31). The reference explains that the production method can include heating the reaction to a range of 220-480 degrees C and can be compressed at a pressure of 446kPa to 3500 kPa at a WHSV from 0.5 to 50hr-1 (para. 77).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the reaction at a pressure of 446kPa to 3500 kPa and a WHSV of 0.5 to 50hr-1, as taught by Benedict for use with the process of Chen, Nimlos, Zhou and Gu because these conditions are known to be effective in generating para-xylene when using a catalyst.
As to the molar ratio of aromatic (toluene) to oxygenate (methanol), Bulin describes a method for preparing p-xylene (title) made by combining toluene and methanol in a reaction mixture with a ZSM-5 zeolite material (abstract). The ratio of toluene to methanol is about 8 (page 3, last para). The reaction operates at a temperature of about 440 degrees C (page 4, para. 6) and is fed using a nitrogen flow and a hydrogen flow (page 4, para. 6). As to the ratio of toluene to methanol, Bulin teaches that the ratio can range from 4/1 to 1.3/1 (page 6, para. 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to feed to reactants in a ratio of 4/1 to 1.3/1 of toluene/methanol, as taught by Bulin for use with the process of Chen, Nimlos, Zhou and Gu because this ratio of reactants is effective in producing para-xylene product.
Claim(s) 19, 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen “Reactions of Mixture of Toluene and Methanol over ZSM-5” and in view of Nimlos, Claire et al. “Experimental and Theoretical Assessments of Aluminum Proximity in MFI Zeolites and its Alteration by Organic and Inorganic Structure-Directing Agents”, submitted in IDS on 6/17/23 and further in view of Zhou (CN 112028730) and further in view of Gu (CN 113979446) and further in view of Helton (US Pub.: 2014/0213840).
Chen describes a method of reacting a mixture of toluene and methanol over a ZSM-5 sieve (title) produce xylene isomers (page 18, right col, last para), such as p-xylene (page 19, left col, line 8). Chen explains that the para-version of the xylene isomers can be improved by optimizing certain features, such as crystal size (page 19, right col, lines 12-15). The ZSM-5 has a SiO2/Al2O3 ratio of 70 (see page 17, right col, “Experimental”, para. 1). ZSM-5 zeolites have an MFI topology. The ZSM-5 is calcined and ion-exchanged (see page 17, “Experimental”, para. 1). ZSM-5 zeolites have an MFI structure.
Chen does not teach that the ZSM-5 has a population of proximate framework aluminum sites characterized by less than about 18% of proximate aluminum sites characterized by a cobalt titration technique.
As to this feature, Nimlos describes an MFI zeolite and assesses the aluminum proximity in these zeolites based on the organic and inorganic structure-directing agents (SDA) used to make these compounds (title). Nimlos explains that the type of SDA used, influences the siting and the arrangement of Al in the zeolite frameworks (abstract). Nimlos describes their use of cobalt titration used to quantifying Al-Al site pairs in MFI zeolites (abstract). In their tests, Nimlos shows the fraction of Al in pairs to range from 0.06 to 0.14% when using DABCO or that it can range from 34-2% when using TPA (see table 1).
After formation of the product, the zeolite made is heated at elevated temperature of about 853 K (see page 9279, right col, para. 3). This can be considered a calcination temperature. The product made is then ion-exchanged (page 9279, right col, section 2.2, para. 1) . The products made with varying Al arrangements can vary the zeolite catalytic and adsorption properties (abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the use of SDA and then quantified using cobalt titration in order to obtain the desired Al pairs from 0.6% to 14%, as taught by Nimlos for use with Chen because this is an optimizable feature, which can be used to adjust the catalytic and adsorption properties.
It would have been obvious to one having ordinary skill in the art to have determined the optimum value of a cause effective variable such as aluminum pairs through routine experimentation in the absence of a showing of criticality. In re Woodruff, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Chen describes in their example that the SiO2/Al2O3 ratio is about 70 (see “experimental” para. 1).
It has been held that a prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985). See MPEP 2144.05.
Alternatively, the claimed range is known, as described by Zhou.
Zhou describes a ZSM-5 molecular sieve (title) that is useable for in producing p-xylene (abstract). The catalyst is a metal-modified ZSM-5 molecular sieve, which ahs a SiO2/Al2O3 ratio of 50-100 (see page 4, para. 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a ZSM-5 molecular sieve that has a SiO2/Al2O3 range of 50-100, as taught by Zhou for use with the ZSM-5 of Chen and Nimlos because Zhou teaches that a broader SiO2/Al2O3 range of 50-100 is effective for use in zeolite catalysts in making p-xylene.
As to the heteroatom and the Si/Q ratio, Gu describes a molecular sieve that has a ZSM-5 framework (page 3, last 3 lines) used for methylating alcohol (abstract), which can produce a p-xylene (see Background, para. 1). The molecular sieve can be a boron-containing molecular sieve (title). Gu explains in the background that ZSM-5 molecular sieved used in toluene methanol allylation reaction to make p-xylene has limitations (Background, para. 1, 2). As a solution to this, use of a boron-containing molecular sieve improves the ZSM-5 and also improves the xylene selectivity (Background, para. 3). In their invention, Gu explains that their preferred ratio of SiO2/B2O3 can be 12-200 (page 4, lines 30-31).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include boron in the MFI in an amount of SiO2/B2O3 of 12-200, as taught by Gu for use with the ZSM-5 of Chen and Nimlos because this improves upon the use of ZSM-5 for making p-xylene with toluene and methanol.
The references do not teach that the MFI zeolite is in the catalyst in an amount of 5-15wt%.
Helton describes a process for producing para-xylene using toluene and methanol in the presence of a catalyst (abstract). The catalyst can include 5-15wt% of a ZSM-5 molecular sieve (abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a ZSM-5 catalyst in an amount of 5-15wt%, as taught by Helton for use with the process of Chen and Nimlos because this amount is effective in producing para-xylene from toluene and methanol.
As to Claim 22, Helton teaches that the methanol used is at least 99wt% (para. 22). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ methanol in an amount of 99wt%, as taught by Helton for use with Chen and Gounder because this ratio is effective in producing a para-xylene product.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen, Nimlos, Zhou, Gu and Helton as applied to claim 19 above, and further in view of Benedict (US Pub.: 2020/0308087) and in view of Bulin (CN 1759081).
The references do not teach the process features for making para-xylene, as described by Claim 20.
As to the WHSV and pressure, Benedict describes a para-xylene product system (title) that can use a ZSM-5 catalyst (para. 31). The reference explains that the production method can include heating the reaction to a range of 220-480 degrees C and can be compressed at a pressure of 446kPa to 3500 kPa at a WHSV from 0.5 to 50hr-1 (para. 77).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the reaction at a pressure of 446kPa to 3500 kPa and a WHSV of 0.5 to 50hr-1, as taught by Benedict for use with the process of Chen, Nimlos, Zhou, Gu and Helton because these conditions are known to be effective in generating para-xylene when using a catalyst.
As to the molar ratio of aromatic (toluene) to oxygenate (methanol), Bulin describes a method for preparing p-xylene (title) made by combining toluene and methanol in a reaction mixture with a ZSM-5 zeolite material (abstract). The ratio of toluene to methanol is about 8 (page 3, last para). The reaction operates at a temperature of about 440 degrees C (page 4, para. 6) and is fed using a nitrogen flow and a hydrogen flow (page 4, para. 6). As to the ratio of toluene to methanol, Bulin teaches that the ratio can range from 4/1 to 1.3/1 (page 6, para. 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to feed to reactants in a ratio of 4/1 to 1.3/1 of toluene/methanol, as taught by Bulin for use with the process of Chen, Nimlos, Zhou, Gu and Helton because this ratio of reactants is effective in producing para-xylene product.
Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chen, Nimlos, Zhou, Gu and Helton as applied to claim 19 above, and further in view of Ding (US Pub.: 2013/0267746).
The references describe production of para-xylene and since the catalyst used is the same, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the same product would be made. Nonetheless, this feature is taught by Ding.
Ding describes a process for producing xylene (title) through the methylation of aromatic compounds using methanol coupled with a transalkylation process (para. 2). Ding explains that the methylation step can use a zeolite catalyst, such as ZSM-5 (para. 16). In this step, the ratio of methyl to phenyl groups is about 2 (para. 23). However, this streat is then sent to a transalkylation unit, which produces a product with a ratio of methyl to pheyl from 1.5 to 2.2 (para. 23). A prima facie case of obviousness exists where the claimed ranges and prior art ranges overlap or are close enough that one skilled in the art would have expected them to have the same properties. See MPEP 2144.05 I.”
This is done by adding some benzene and toluene to the transalkylation step (para. 24). By doing this, Ding explains that less benzene is produced or even eliminated (para. 5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further process the product by adding more reactants to the finished product and reacting the same in order to obtain a ratio of methyl to phenyl ratio of 1.5 to 2.2, as taught by Ding for use with Chen, Nimlos, Zhou, Gu and Helton because this produces less or eliminates formation of benzene.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/SHENG H DAVIS/Primary Examiner, Art Unit 1732 September 10, 2026
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