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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3/3/26 has been entered.
Claim Status
The claims are newly amended.
Response to Arguments
Applicant’s arguments, see pages 6-10, filed 3/3/26, with respect to the rejection(s) of claim(s) 1-3, 5-22 under the Final have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of the reference below.
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
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/SHENG H DAVIS/Primary Examiner, Art Unit 1732 April 29, 2026
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