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 .
Status of Claims
Claims 1-3, 5-7, and 9-15 are currently pending. Claims 1, 5-7, 9-12, and 15 are currently amended. Claims 4 and 8 have been canceled.
Claim Rejections - 35 USC § 103
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
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.
Claims 1, 2, 5, 7, & 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al. (U.S. Patent Pub. US-20160279613A1) in view of Chinzei et al. '900 (U.S. Patent Pub. US20220106900A1).
In regard to claim 1, Suzuki et al. teaches an exhaust gas purification catalyst comprising a substrate [0019], a catalyst layer formed on a cell wall of the substrate [0020], a first (i.e. lower) catalyst layer carrying platinum [0021], and a second (i.e. upper) catalyst layer carrying rhodium [0018]. Suzuki et al. further teaches that the first layer is formed from the front edge of the substrate, corresponding to an end portion on the upstream side of the substrate described in the instant application [0044] (corresponding to lines 1-8 of claim 1).
Suzuki et al. does not teach that the second catalyst layer is comprised of an upstream coating layer formed from an upstream portion of the substrate and a downstream coating layer formed from a downstream portion of the substrate (as per lines 9-13 of claim 1). However, Chinzei et al. ‘900 teaches a first catalyst layer, 20, in contact with the catalyst substrate stretching from its upstream end [0023], and comprising Pt or Pd particles [0030] and optionally an OSC material [0037], which corresponds to the first catalyst coating layer of the present application. Chinzei et al. ‘900 teaches a second catalyst layer, 30, in contact with the catalyst substrate stretching from its downstream end [0047] and comprising Rh particles [0048], and optionally an OSC material [0054], which corresponds to the downstream coating layer of the present application. Chinzei et al. ‘900 teaches a third layer, 40, in contact with at least first layer 20 and extending from the upstream end of the catalyst substrate [0060] comprising Rh particles [0061], and optionally an OSC material [0066], which corresponds to the upstream coating layer of the present application. When three coating layers with varied compositions were used, a superior conversion of NOx was observed as compared to only two coating layers (Table 1). It would have been obvious to one of ordinary skill, in the art at the time, to add the third coating layer taught by Chinzei et al. ‘900 to the catalyst device taught by Suzuki et al. to yield the claimed invention of the present application. Both Chinzei et al. ‘900 and Suzuki et al. relate to exhaust gas purification catalysts and a person of ordinary skill would be able to apply the teachings of Chinzei et al. ‘900 to Suzuki et al. Therefore, it would have been obvious to one of ordinary skill, in the art at the time, to add the third catalyst coating layer of Chinzei et al. ‘900 to the catalyst taught by Suzuki et al. to improve the catalytic conversion of NOx in an exhaust gas purification catalyst.
Suzuki et al. teaches that the upper layer contains two types of ceria-zirconia-based oxides with different specific surface areas (SSAs) and may further contain alumina [0021]. The ceria-zirconia-based composite material with a larger SSA has a SSA of greater than or equal to 40 m2/g and the ceria-zirconia-based composite material with a smaller SSA has a SSA of less than or equal to 4 m2/g, both of which read onto the OSC materials recited [0022]. Suzuki et al. does not explicitly teach the inclusion of a third, medium specific surface area OSC material as a part of the second layer composition (as per lines 14-19 of claim 1). The range of the composite material with a larger SSA encompasses the range of the high SSA material of the instant application, an area of more than 40 m2/g, and overlaps the range of the medium SSA material 4-40 m2/g inclusive. The range of the composite material with a smaller SSA encompasses the range of the low SSA OSC material, less than 4 m2/g, and overlaps the range of the medium SSA OSC material of the instant application, 4-40 m2/g inclusive. Overlapping ranges are prima facie obvious (see MPEP 2144.05 I). Suzuki et al. identifies that the inclusion of these materials can suppress a pressure loss in the cell and generate improved OSC performance [0049], which suggests that the composition and SSAs of the OSC in the catalyst composition taught by Suzuki et al. are results-effective variables. As such, one of ordinary skill in the art at the relevant time would have found it prima facie obvious to have optimized the composition of the OSC materials used in order to maximize OSC performance (see MPEP 2144.04 II A and B regarding routine optimization).
Suzuki et al. and Chinzei et al. ‘900 do not teach the specific distribution of low and medium SSA OSC materials within the upstream and downstream coating layers as instantly claimed (as per lines 18-21 of claim 1). However, Suzuki et al. teaches that when the upper catalyst layer contains an OSC material with a large SSA, the NOx purification rate is increased, while the inclusion of an OSC material with a low SSA can suppress a pressure loss [0018]. The combination of high and low SSA OSC materials suggests that the amount and distribution of OSC materials contained in the catalyst is a results-effective variable. As discussed, prior, Suzuki et al. teaches the use of two OSC materials of high and low SSAs with property ranges which overlap the ranges of the instant application’s high, medium, and low SSA OSC materials. As such, it would be obvious to add a third material in the taught range to increase the variety of SSAs and impede metal alloying.
In regard to claim 2, Suzuki et. al. teaches that the OSC materials used (with larger or smaller SSAs) may be ceria-zirconia-based composite oxides as instantly claimed.
In regard to claim 5, Suzuki et al. does not teach the claimed lengths of a downstream and
upstream coating layer or the first coating layer. However, Chinzei et al. ‘900 teaches that the first catalyst layer, 20, corresponding to the downstream coating layer, may be 15-50% of the length of the substrate overlapping the instantly claimed range of 20-50% [0023]. Further, the second catalyst layer, 30, may be 40-70% of the length of the length of the substrate, which overlaps the instantly claimed range of 30-70% [0047]. Further, the third catalyst layer, 40, corresponding to the upstream coating layer, may be 40-70% of the length of the substrate which overlaps the instantly claimed range of 30-70%. Overlapping ranges are prima facie obvious (see MPEP 2144.05 I). It would have been obvious to a person having ordinary skill in the art at the time of the creation of the invention to apply the taught length of the layers of Chinzei et al. ‘900 to the device of Suzuki et al. in order to maximize catalytic efficiency while preventing the alloying of the two catalytic metals from layer overlap.
In regard to claim 7, Suzuki et al. teaches that the first catalyst layer (i.e. Pt-containing lower layer) is disposed between the Rh-containing upper catalyst layer [0017] which corresponds to the upstream and downstream coating layers of the present application, and the substrate.
In regard to claim 9, Suzuki et al. does not teach the weight% loadings of the high, medium, and low SSA OSC materials within the upstream coating layer, downstream coating layer, and second catalyst coating layer. However, Chinzei et al. ‘900 teaches that the substrate has a finite loading capacity [0039], [0052], & [0056]. It would be obvious to optimize the distribution of different OSC to maximize oxygen storage efficiency while not exceeding the finite loading capacity of the substrate. As such, one of ordinary skill in the art at the relevant time would have found it obvious to have optimized the ratio of the OSC materials used with respect to each other in the different catalyst coating layers in order to maximize OSC performance (see MPEP 2144.04 II A and B regarding routine optimization). It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed ranges through process optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 10, Suzuki et al. does not teach that the catalyst particles in the first catalyst layer are palladium. However, Chinzei et. al. ‘900 teaches that the catalyst particles in the first catalyst layer may be palladium [0030]. It would have been obvious to one having ordinary skill in the art at the time the invention was made to exchange the platinum particles of Suzuki et al. for the palladium particles of Chinzei et al. ‘900 as both platinum and palladium are known for having hydrocarbon oxidation activity [0005] and the catalyst device of Chinzei et al. ‘900, which contained Pd particles, exhibited high hydrocarbon conversion rates (Example 1, [0097], & Table 1). A person of ordinary skill in the art at the time of the creation of the invention would recognize the equivalency of Pt and Pd as catalyst for hydrocarbon conversion and see a benefit to using Pd over Pt for increased conversion as suggested by Chinzei et al. ‘900.
In regard to claim 11, the claim recites an intended use which is not considered to limit the scope of the claim. The combined teachings of Suzuki et al. and Chinzei et al. ‘900 teach the structure of the invention as claimed and thus it is capable of performing the intended use.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et. al. and Chinzei et al. ‘900 as applied to claim 2 above and further in view of Chinzei et al. ‘248 (U.S. Patent Pub. No. US-2019126248A1).
Suzuki et al. does not teach that the OSC materials must have a pyrochlore structure. Chinzei et al. ‘248 teaches that the use of an OSC material with a pyrochlore-type structure in the upper layer of a catalyst coating layer provides improved exhaust gas purifying performance, OSC performance, and pressure loss of an exhaust gas purification catalyst [0011]. The taught OSC material with a pyrochlore structure is taught to have a SSA of less than 10 m2/g and preferably 1-5 m2/g, which overlaps the range of the low SSA OSC material of the instant application [0032].
It would have been obvious to one of ordinary skill, in the art at the time, to modify the upper catalyst coating layer of Suzuki et al. by replacing the ceria-zirconia-based composite oxides used as a low SSA OSC material with the ceria-zirconia-based composite oxide comprising a pyrochlore structure taught in Chinzei et al. ‘248 to yield the claimed invention of the instant application. Both pieces of art are related to two-layer exhaust gas purification catalysts and one of ordinary skill in the art would recognize the material advantage of the OSC materials described in Chinzei et al. ‘248 when applied to Suzuki et al. Therefore, it would have been obvious to one of ordinary skill, in the art at the time, to replace the OSC material with a lower specific surface area taught in Suzuki et al. with the OSC material with a pyrochlore structure as taught in Chinzei et al. ‘248 to improve the performance of an exhaust gas purification catalyst.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al. and Chinzei et al. ‘900 as applied to claim 1 and further in view of Miyoshi et al. (Japanese Patent Pub. No. JP-2010201284A).
In regard to claim 6, Suzuki et al. teaches that the first catalyst layer is disposed between the Rh-containing upper catalyst layer [0017], which corresponds to the upstream and downstream coating layers of the present application, and the substrate. Suzuki et al. does not teach that the lower catalyst layer (i.e. first catalyst coating layer) is disposed on the upper catalyst layer (i.e. upstream coating layer). Miyoshi et al. teaches an exhaust gas purification catalyst where rhodium is supported in the first catalyst layer, closest to the substrate, while platinum and palladium is supported in the second catalyst layer which is farther from the substrate [0010]. Miyoshi further teaches that supporting rhodium in the first layer of the catalyst shields the rhodium from a lean oxygen environment, where it is sensitive to thermal grain growth which impedes catalyst performance [0007]. Therefore, it would have been obvious to apply the teachings of Miyoshi et al. to the modified teachings of Suzuki et al. and Chinzei et al. ‘900 to reverse the layer composition of the catalyst to prevent Rh particle grain growth which negatively impacts catalyst performance.
Claims 12, 14, & 15 are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al.
In regard to claim 12, Suzuki et al. teaches an exhaust gas purification catalyst comprising a substrate [0019], a catalyst layer formed on a cell wall of the substrate [0020], a first (i.e. lower) catalyst layer carrying platinum [0021], and a second (i.e. upper) catalyst layer carrying rhodium [0018]. Suzuki et al. further teaches that the first layer is formed from the upstream end of the substrate and that the second layer is formed from a downstream end of the substrate with respect to gas flow [0027]. Suzuki et al. teaches that the second catalyst layer comprises a larger SSA OSC material (i.e. ceria-zirconia-based composite oxides) with a SSA greater than or equal to 40 m2/g [0022], which overlaps the claimed high SSA material with a SSA of 60-90 m2/g and medium SSA OSC material with a SSA of 30-40m2/g, and a smaller SSA OSC material with a SSA less than or equal to 4 m2/g [0022], which overlaps the claimed low SSA OSC material with a SSA of 0.5-2.0 m2/g. Suzuki et al. teaches that the larger SSA OSC material may be loaded in the catalyst layer in an amount greater than or equal to 12 g/L, which overlaps the loading of the high and medium SSA OSC material loadings of 20-40 g/L, and the smaller SSA OSC material may be loaded in the catalyst layer in an amount greater than or equal to 8 g/L, which overlaps the claimed loading of the low SSA OSC material of 10-30 g/L [0022]. Suzuki et al. states that an optimum loading of both the high and low SSA OSC materials can lead to a suppression of a pressure loss alongside excellent OSC performance [0024] & [0064], suggesting that the loading of the various OSC materials is a results-effective variable.
With respect to the encompassing and overlapping ranges previously discussed, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time of invention to select the portion of the prior art’s range which is within the range of the applicants’ claims because it has been held prima facie case of obviousness to select a value in a known range by optimization for the results. In re Aller, 105 USPQ 233. Additionally, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time invention was made to have selected the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
Suzuki et al. does not teach the inclusion of a third, medium specific surface area OSC material as a part of the second layer composition. Suzuki et al. identifies that at higher loadings, the addition of further OSC material of a certain SSA leads to a saturated effect on the overall OSC performance, and that there is a synergistic effect between including both a larger and smaller SSA OSC material [0064]. Therefore, it would have been obvious to one of ordinary skill to employ an additional OSC material with a SSA different from those of the low and high SSA OSC materials taught in order to overcome said saturation barrier. Furthermore, the range of the composite material with a larger SSA (≥40 m2/g) encompasses the range of the high SSA material of the instant application (60-90 m2/g), and overlaps the range of the medium SSA material (30-40 m2/g). Overlapping ranges are prima facie obvious (see MPEP 2144.05 I). As such, one of ordinary skill in the art at the relevant time would have found it obvious to have optimized the composition of the OSC materials to include a third material between SSA of the taught larger and smaller SSA OCS materials used in order to maximize OSC performance of the catalyst (see MPEP 2144.04 II A and B regarding routine optimization).
In regard to claim 14, Suzuki et al. teaches that the first catalyst layer comprises platinum particles as a catalytic metal as instantly claimed [0020].
In regard to claim 15, the claim recites an intended use which is not considered to limit the scope of the claim. Suzuki et al. teaches the structure of the invention as claimed and thus it is capable of performing the intended use.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al. as applied to claim 12 above in view of Chinzei et al. '900.
In regard to claim 13, Suzuki et al. teaches that the second catalyst layer has a width of 65-95% the whole length of the catalyst substrate as instantly claimed. Suzuki et al. does not teach that the first catalyst layer has a width of 15-50% the whole length of the catalyst substrate, instead teaching 65-95%.
However, Chinzei et al. ‘900 teaches that the preferably platinum or palladium-containing first catalyst layer has a width of 15-50% the length of the substrate [0023] as instantly claimed. At this length, the first catalyst layer has effective at oxidizing and removing hydrocarbons before the exhaust gas contacted the rhodium-containing second and third catalyst layers (equivalent to the instantly claimed second catalyst layer) in order to boost the NOx conversion of the catalyst overall ([0030], [0031], see Table 1 Examples 1-4) while decreasing the required precious metal via a coating length shorter than those of Suzuki et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to decrease the length of the first catalyst layer taught by Suzuki et al. (65-95%) to be 15-50% the length of the substrate as suggested by Chinzei et al. ‘900 to achieve a comparable NOx conversion with less platinum/palladium.
Claims 1, 5, 7, 9, 10, and 11 under 35 U.S.C. 103 as being unpatentable over Suzuki et al. and in view of Tanaka (Int’l Pub No. WO2020241248A1, English equivalent US20220234030A1 cited herein) and Onoe et al. (Int’l Pub No. WO2021261209A1).
In regard to claim 1, Suzuki et al. teaches an exhaust gas purification catalyst comprising a substrate [0019], a catalyst layer formed on a cell wall of the substrate [0020], a first (i.e. lower) catalyst layer carrying platinum [0021], and a second (i.e. upper) catalyst layer carrying rhodium [0018]. Suzuki et al. further teaches that the first layer is formed from the front edge of the substrate, corresponding to an end portion on the upstream side of the substrate described in the instant application [0044] (corresponding to lines 1-8 of claim 1).
Suzuki et al. does not teach that the second catalyst layer is comprised of an upstream coating layer formed from an upstream portion of the substrate and a downstream coating layer formed from a downstream portion of the substrate (as per lines 9-13 of claim 1). However, Tanaka teaches an exhaust gas purification catalyst comprising a substrate and catalyst layer with a first section located upstream and a second section located downstream with respect to exhaust gas flow. Both the first section, V1, and second section, V2, are made up by a multilayer structure, which corresponds to the first and second catalyst coating layers of the present application [0021]. The second catalyst layer, 14, of the first section is laminated from the upstream side of the substrate, 111, which corresponds to the formation of an upstream coating layer from an end portion of an upstream side of the substrate in the present application [0021]. Similarly, Tanaka teaches that a fourth catalyst later, 16, is laminated onto the substrate from side 112 of the substrate, which corresponds to the formation of a downstream coating layer formed from an end portion in a downstream side of the substrate in the present application [0022]. Tanaka teaches that the third and fourth catalyst layers contain rhodium [0037], [0068] and contain an OSC material with a SSA between 30-210 m2/g ([0039], [0069]-[0070], see [0029] for a discussion of acceptable OSC materials). Tanaka suggests that sectioning the catalyst into an upstream and downstream component which differ in composition can drastically improve catalytic performance by effectively preventing catalyst poisoning [0017]. Therefore, it would have been obvious to one of ordinary skill, in the art at the time, to modify the upper catalyst layer of Suzuki et al. to create two sections with varied compositions as taught by Tanaka in order to yield the upstream and downstream coating layers of claim 4. Both Suzuki et al. and Tanaka relate to exhaust gas purification catalysts and one of ordinary skill in the art would be capable of applying the teachings of Tanaka to Suzuki et al. It would further have been obvious to one of ordinary skill in the art at the time the invention was made to replace the continuous upper catalyst layer of Suzuki et al. with two sections of different composition as taught in Tanaka in order to finely control the ratio of catalytic components in the coating layer to decrease catalyst poisoning by phosphorus and increase catalytic activity.
Suzuki et al. teaches that the upper layer contains two types of ceria-zirconia-based oxides with different specific surface areas (SSAs) and may further contain alumina [0021]. The ceria-zirconia-based composite material with a larger SSA has a SSA of greater than or equal to 40 m2/g and the ceria-zirconia-based composite material with a smaller SSA has a SSA of less than or equal to 4 m2/g, both of which read onto the OSC materials recited [0022]. Suzuki et al. does not teach the inclusion of a third, medium specific surface area OSC material as a part of the second layer composition (as per lines 14-19 of claim 1). The range of the composite material with a larger SSA encompasses the range of the high SSA material of the instant application, an area of more than 40 m2/g, and overlaps the range of the medium SSA material 4-40 m2/g inclusive. The range of the composite material with a smaller SSA encompasses the range of the low SSA OSC material, less than 4 m2/g, and overlaps the range of the medium SSA OSC material of the instant application, 4-40 m2/g inclusive. Overlapping ranges are prima facie obvious (see MPEP 2144.05 I). Suzuki et al. identifies that the inclusion of these materials can suppress a pressure loss in the cell and generate improved OSC performance [0049], which suggests that the composition and SSAs of the OSC in the catalyst composition taught by Suzuki et al. are results-effective variables. As such, one of ordinary skill in the art at the relevant time would have found it prima facie obvious to have optimized the composition of the OSC materials used in order to maximize OSC performance (see MPEP 2144.04 II A and B regarding routine optimization).
Suzuki et al. and Tanaka do not teach the specific distribution of low and medium SSA OSC materials within the upstream and downstream coating layers as instantly claimed (as per lines 18-21 of claim 1). However, Suzuki et al. teaches that when the upper catalyst layer contains an OSC material with a large SSA, the NOx purification rate is increased, while the inclusion of an OSC material with a low SSA can suppress a pressure loss [0018]. The combination of high and low SSA OSC materials suggests that the amount and distribution of OSC materials contained in the catalyst is a results-effective variable. As discussed prior, Suzuki et al. teaches the use of two OSC materials of high and low SSAs with property ranges which overlap the ranges of the instant application’s high, medium, and low SSA OSC materials. As such, it would have been obvious to add a third material in the taught range to increase the variety of SSAs and impede metal alloying.
Onoe et. al. teaches that both upper layers of the catalyst should include an OSC material with a low SSA (about 40-60 m2/g) and may include a conventional SSA (>60 m2/g, [0025]). Inclusion of the low SSA OSC material is imperative to catalyst longevity as OSC materials with lower SSAs are less likely to lose specific surface area over time, suppressing grain growth of the catalytic metal and catalyst deterioration [0028]. Further, the low SSA OSC material may be added to the rear portion in a greater amount than in the front section to finely control the initial OSC and improve catalyst longevity [0036]. As such one of ordinary skill in the art at the relevant time would have found it prima facie obvious to have optimized the composition of the OSC materials used in order to maximize OSC performance (see MPEP 2144.04 II A and B regarding routine optimization). It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed ranges through process optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 5, Suzuki et. al. does not teach the claimed lengths of a downstream and upstream coating layer or the first coating layer. Tanaka teaches that the lower catalyst layer may be comprised of two portions, an upstream first catalyst layer [0021] and a downstream third catalyst layer [0022], which may have the same or different compositions [0065]. The first catalyst layer may have a length of 20-70% the length of the substrate [0077], which overlaps the claimed length of the first coating layer (20-50% of substrate). Tanaka teaches that an upper catalyst layer may contain two portions, the second catalyst layer [0021], and the fourth catalyst layer [0022], with lengths L1 and L2. Tanaka further teaches that the second catalyst layer with length L1 may have a length of 20-70% the length of the substrate [0077], which overlaps the claimed range of the upstream coating layer (30-70% length of substrate). It is then understood that the fourth catalyst layer has a length of 30-80% of the substrate which overlaps the claimed range of the downstream coating layer (30-70% length of substrate). Tanaka teaches that controlling the length ratio of the first section to the second section can enhance performance during start-up and simplify manufacture [0077]. Overlapping ranges are prima facie obvious (see MPEP 2144.05 I). It would have been obvious to a person having ordinary skill in the art at the time of the creation of the invention to apply the taught length of the layers of Tanaka to the device of Suzuki et. al. to maximize performance during start-up and high-speed operation [0077].
In regard to claim 7, Suzuki et. al. teaches that the Pt-containing lower catalyst layer, which corresponds to the first catalyst layer of the present application, is disposed between the Rh-containing upper catalyst layer [0017] which corresponds to the upstream and downstream coating layers of the present application, and the substrate.
In regard to claim 9, Suzuki et al. does not teach the specific weight% loading on the high, medium, and low SSA OSC materials in the catalyst composition. However, Onoe et al. teaches that both upper layers of the catalyst should include an OSC material with a low SSA (about 40-60 m2/g) and may include a conventional specific surface area (>60 m2/g, [0025]). Inclusion of the low SSA OSC material is imperative to catalyst longevity as OSC materials with lower SSAs are less likely to lose specific surface area over time, suppressing grain growth of the catalytic metal and catalyst deterioration [0028]. Further, the low SSA OSC material may be added to the rear portion in a greater amount than in the front section to finely control the initial OSC and improve catalyst longevity (paragraph [0036]). As such one of ordinary skill in the art at the relevant time would have found it prima facie obvious to have optimized the composition of the OSC materials used in order to maximize OSC performance (see MPEP 2144.04 II A and B regarding routine optimization). It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed ranges through process optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 10, Suzuki et al. teaches that the catalyst particles in the first layer are platinum. Suzuki et al. does not teach that the catalyst particles in the first catalyst layer are palladium. However, Tanaka teaches that the catalyst particles in the first catalyst layer (corresponding to the first catalyst coating layer of the present application) may be palladium [0017]. It would be obvious to one having ordinary skill in the art at the time the invention was made to exchange the platinum particles of Suzuki et al. for the palladium particles of Tanaka as both platinum and palladium are known for having hydrocarbon oxidation activity (Tanaka, [0026]) and palladium may be superior for its low-temperature activity (Tanaka, [0009]). A person of ordinary skill in the art at the time of the creation of the invention would have recognized the equivalency of Pt and Pd as catalyst metals for hydrocarbon conversion and see a benefit to using Pd over Pt for increased conversion as suggested by Tanaka.
In regard to claim 11, the claim recites an intended use which is not considered to limit the scope of the claim. Suzuki et. al. and Tanaka teach the structure of the invention as claimed and thus it is capable of performing the intended use.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al., Tanaka, Onoe et al., and further in view of Miyoshi et. al.
In regard to claim 6, Suzuki et. al. teaches that the Pt-containing lower catalyst layer, which
corresponds to the first catalyst layer of the present application, is disposed between the Rh-containing
upper catalyst layer [0017] which corresponds to the upstream and downstream coating
layers of the present application, and the substrate. Suzuki et. al. does not teach that the lower catalyst
layer (i.e. first catalyst coating layer) is disposed on the upper catalyst layer (i.e. upstream coating layer).
Miyoshi et. al. teaches an exhaust gas purification catalyst where rhodium is supported in the first
catalyst layer, closest to the substrate, while platinum and palladium is supported in the second catalyst
layer which is farther from the substrate [0010]. Miyoshi further teaches that supporting rhodium in the first layer of the catalyst shields the rhodium from a lean oxygen environment, where it is sensitive to thermal grain growth which impedes catalyst performance [0007]. It would have been obvious to apply the teachings of Miyoshi et. al. to the modified teachings of Suzuki et al., Tanaka, and Onoe et al. to reverse the layer composition of the catalyst to prevent Rh particle exposure to a lean oxygen environment, and subsequent grain growth, which negatively impacts catalyst performance.
The rejection of claim 13 under 35 U.S.C. 103 over Suzuki et al. in view of Tanaka is hereby withdrawn in light of the amendments made to claims 12 and 13, wherein claim 13 no longer depends from claim 1.
Response to Arguments
Applicant's arguments filed 24 April 2026 have been fully considered but they are not persuasive.
Applicant traverses the rejection of claims 1-2, 12, 14, & 15 under U.S.C. 103 as being unpatentable over Suzuki et al. because Suzuki et al. does not teach the features of claims 4 and 8 incorporated into claim 1 wherein the catalyst comprises a second catalytic layer made of two separate layers in an upstream and downstream position, and that the two layers vary in composition with respect to the materials comprised therein. The examiner acknowledges that Suzuki et al. on its own does not disclose a second catalytic coating layer comprised of two different coating layers with varied composition. For this reason, Chinzei et al. ‘900 was included in the rejection of the limitations of original claims 4 and 8, now incorporated into claim 1. The catalyst of Chinzei et al. ‘900 has been reproduced below as Reference Figure B, wherein layers 30 and 40 are Rh-containing catalyst coating layers which also contain OSC materials [0056] & [0068]. As noted above in the rejection of claim 1 over Suzuki et al. in view of Chinzei et al. ‘900, a person of ordinary skill in the art at the time the invention was made would readily envision from the combination of the catalyst of Suzuki et al. and the catalyst of Chinzei et al. ‘900 a second catalytic coating layer which is comprised of two different coating layers. The limitation that the second catalytic coating later is formed on (or in contact with) the substrate is outside the scope of claim 1.
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Reference Figure A. Reproduced Fig. 3 of Suzuki et al.
Reference Figure B. Reproduced Fig. 1 of Chinzei et al. ‘900.
Reference Figure C. Reproduced Fig. 1 of the instant application.
Applicant further argues that Suzuki et al. does not teach the specific composition of OSC materials within the second layer. However, as stated above, the SSA ranges of the two OSC materials disclosed by Suzuki et al. overlap or encompass the SSA ranges of the instantly claimed high, medium, and low SSA OSC materials. Further, as previously stated, Suzuki et al. teaches that the SSA of the OSC materials employed and the overall composition of OSC materials in the second catalyst layer are important to the properties of the final catalyst, and a person of ordinary skill in the art at the time the invention was made would be motivated to optimize the composition of the second catalyst layer for best performance.
Applicant further argues that the combination of Suzuki et al. and Chinzei et al. ‘900, as discussed in the previous office action, does not remedy the deficiencies of Suzuki et al. because Chinzei et al. ‘900 does not disclose an upstream coating layer which incorporates the high specific surface area OSC material and the low specific surface area OSC material, and a downstream layer which comprises the medium specific surface area material and the low specific surface area OSC material. The examiner acknowledges that the reference on its own does not teach the recited limitation. However, the combined teachings of Suzuki et al., which teaches the use of two OSC materials which have SSA ranges which overlap the high, medium, and low SSA OSC material ranges, with Chinzei et al. ‘900, which teaches a two-layer second catalyst layer, and the evidence within both references that demonstrates that the position and composition of OSC materials with varied SSAs deposited on the catalyst are results-effective variables (see above rejection), for many of the reasons which applicant cites, the limitations of claim 1 would have been obvious to a person of ordinary skill in the art at the time the invention was made through routine experimentation and process optimization.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Further with regard to claim 1 (first embodiment), applicant also states that the structure, composition, and placement of the different catalytic coating layers are important to the device’s function, and the examiner agrees with this statement. However, applicant’s claim echoes the findings of the prior art. Applicant further argues that the NOx conversion rate in a rich atmosphere, the OSC at a low temperature, and OSC at a high temperature in the provided Examples 1-5, as compared to catalysts lacking the three different SSA OSC materials (Comparative Examples 1-3) were markedly improved as a direct result of the inclusion of the medium SSA OSC material (Applicant Remarks pp. 4-7). While applicant does not explicitly state that the cited data are unexpected results, the remarks have been treated as such.
Firstly, the remarks by applicant are not commensurate with the scope of claim 1. Examples 1-5 and Comparative Examples 1-3 were conducted using a 65 m2/g ACZ composite oxide, 35 m2/g ACZ composite oxide, and 1.5 m2/g pyrochlore CZ composite oxide while claim 1 broadly recites OSC materials with >40 m2/g, 4-40 m2/g, and <4 m2/g surface areas. The conclusions drawn about the increased performance under the tested conditions do not necessarily provide a basis that the inclusion of a medium SSA OSC material, as argued by applicant, would necessarily lead to an unpredictably superior result in all materials covered by the broad scope of claim 1.
Secondly, applicant has passively stated that the inclusion of the high, medium, and low SSA OSC materials enabled both high NOx and OSC performance, irrespective of the configuration of the materials (Applicant Remarks pp. 5 & 7). Applicant has not presented an argument as to why said result would have been unexpected to a person of ordinary skill in the art upon review of the relevant teachings of the prior art cited. Suzuki et al. teaches OSC materials with SSA in the three instantly claimed ranges [0022]. Suzuki et al. identifies that the inclusion of these materials can suppress a pressure loss in the cell and generate improved OSC performance [0049], and that when the upper catalyst layer contains an OSC material with a large SSA, the NOx purification rate is increased, while the inclusion of an OSC material with a low SSA can suppress a pressure loss [0018]. The compensatory effect of mixing materials with different SSAs is explicitly discussed as well [0064]. The addition of a third material which had a SSA that overlaps the taught ranges of Suzuki et al. and the medium SSA range instantly claimed would have been obvious to one of ordinary skill, and could have predictably improved performance by mixing the properties of the low SSA material (which experimentally was shown to reduce pressure losses), and the higher SSA material (shown to better release oxygen and overall improve OSC performance) [0064].
With regard to claims 12, 14, and 15, claim 12 has been amended to no longer depend from claim 1, and does not recite that the catalyst disclosed comprises a second catalytic coating layer which is comprised of two different coating layers formed on the substrate. Therefore, the argument presented is moot. No further argument specific to claims 14 and 15, which depend from claim 12, are presented.
Applicant traverses the rejection of claim 3 over Suzuki et al. in view of Chinzei et al. ‘248 on the grounds that Chinzei et al. ‘248 does not remedy the deficiencies identified in regard to claims 1 and 2. Applicant's argument is not considered persuasive for the same reasons as detailed with regard to claims 1, 2, 12, 14, & 15.
Applicant traverses the rejections of claims 4-5, 7-11, and 13 over Suzuki et al. in view of Chinzei et al. ‘900 and Chinzei et al. ‘248 via their dependence on claim 1. The traversal of the rejection of claim 13 on the grounds of its dependency on claim 1 is moot as claim 13 has been amended to depend from independent claim 12, not claim 1. The traversal of the rejection of claims 4 and 8 are moot as the claims have been canceled. Applicant's argument with regard to the remaining claims is not considered persuasive for the same reasons as detailed with regard to claims 1, 2, 12, 14, & 15.
Applicant traverses the rejection of claim 6 over Suzuki et al. in view of Miyoshi et al. on the grounds that Miyoshi et al. does not remedy the deficiencies identified in regard to claims 1. Applicant's argument is not considered persuasive for the same reasons as detailed with regard to claims 1, 2, 12, 14, & 15.
Applicant traverses the rejection of claims 4-5, 7-11, & 13 over Suzuki et al. in view of Tanaka because Suzuki et al. does not teach a second catalytic coating layer which is comprised of two different coating layers or that the upstream coating layer incorporates the high and low specific surface area OSC materials and that the downstream coating layer incorporates the medium and low specific surface area OSC materials. Applicant further argues that Tanaka does not remedy the deficiencies of Suzuki et al. Applicant’s arguments against the rejection of claim 4 are moot as claim 4 has been canceled. Applicant’s arguments against claim 13 are moot as the rejection of claim 13 over Suzuki et al. in view of Tanaka has been withdrawn. With respect to remaining claims 5, 7, 9, 10, and 11, the examiner disagrees with applicant’s characterization of the content of Tanaka. As discussed above in the rejection of amended claim 1 over Suzuki et al. in view of Tanaka, Tanaka teaches an exhaust gas purification catalyst comprising a substrate and catalyst layer with a first section located upstream and a second section located downstream with respect to exhaust gas flow. Both the first section, V1, and second section, V2, are made up by a multilayer structure, which corresponds to the first and second catalyst coating layers of the present application [0021]. The second catalyst layer, 14, of the first section is laminated from the upstream side of the substrate, 111, which corresponds to the formation of an upstream coating layer from an end portion of an upstream side of the substrate in the present application [0021]. Similarly, Tanaka teaches that a fourth catalyst later, 16, is laminated onto the substrate from side 112 of the substrate, which corresponds to the formation of a downstream coating layer formed from an end portion in a downstream side of the substrate in the present application [0022]. Tanaka teaches that the third and fourth catalyst layers contain rhodium [0037], [0068] and contain an OSC material with a SSA between 30-210 m2/g ([0039], [0069]-[0070], see [0029] for a discussion of acceptable OSC materials). The device of Tanaka is reproduced below as Reference Figure D.
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Reference Figure D. Reproduced Fig. 2 of Tanaka.
Tanaka clearly teaches a second catalytic coating layer which is comprised of two different coating layers with varied compositions, and applicant has not presented arguments that the aforementioned reason for combining Suzuki et al. and Tanaka is flawed. Thus, the argument that Tanaka does not teach a second catalytic coating layer which is comprised of two different coating layers is unpersuasive.
Tanaka teaches that the upstream and downstream second catalyst layers may include an OSC material with a SSA of 30-210 m2/g, and that said second catalyst layers comprise two OSC materials with a low (<4 m2/g) and high (>40 m2/g) SSA (claim 4). Tanaka alone does not teach that the upstream coating layer incorporates a high and low SSA OSC material and the downstream coating layer comprises a medium and low SSA OSC material.
In response to applicant's arguments against Suzuki et al. and Tanaka individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
As previously stated, Suzuki et al. teaches that the SSA of the OSC materials employed and the overall composition of OSC materials in the second catalyst layer are important to the properties of the final catalyst, and a person of ordinary skill in the art at the time the invention was made would be motivated to optimize the composition of the second catalyst layer for best performance. Tanaka further teaches that preferable configurations of the device include where pore volume, which is directly related to the SSA of composite oxides, is higher in the upstream layer as compared to the downstream layer to maximize the purification effect during high-speed operation [0076]. Therefore, a person of ordinary skill would have been motivated to place high SSA OSC materials in the upstream portion of the second layer.
Furthermore, Suzuki et al. teaches that when the upper catalyst layer contains an OSC material with a large SSA, the NOx purification rate is increased, while the inclusion of an OSC material with a low SSA can suppress a pressure loss [0018]. The combination of high and low SSA OSC materials suggests that the amount and distribution of OSC materials contained in the catalyst is a results-effective variable. As discussed prior, Suzuki et al. teaches the use of two OSC materials of high and low SSAs with property ranges which overlap the ranges of the instant application’s high, medium, and low SSA OSC materials. As such, it would have been obvious to add a third material in the taught range to increase the variety of SSAs to balance decreased pressure loss with increased OSC performance.
As such, through the combination of the teachings of Suzuki et al. and Tanaka, the limitations of claims 4 and 8, now imported into amended claim 1, would have been obvious to one of ordinary skill after routine experimentation and process optimization. Therefore, applicant’s arguments against the rejection of claims 4 and 8, now amended claim 1, are not considered persuasive. Applicant further argues that claims 7-11 and 13 are allowable via their dependence on claim 1 without further explanation of how the specific limitations of the claims overcome the prior art cited. As such, these arguments are not considered persuasive. Applicant’s argument that claim 13 is allowable by virtue of its dependence of claim 1 is considered moot as claim 12, from which claim 13 depends, has been amended to be independent of claim 1, and thus the argument is moot.
Applicant traverses the rejection of claim 6 over Suzuki et al. in view of Tanaka and Miyoshi et al. on the grounds that Tanaka and Miyoshi et al. do not remedy the deficiencies of Suzuki et al. As discussed above, applicant’s arguments with respect to amended claim 1, which incorporates the limitations of claims 4 and 8, are not persuasive as the limitations are rendered obvious by Suzuki et al. in view of Tanaka and Onoe et al. Applicant does not present further arguments as to how the limitations of claim 6 overcome the prior art presented, and thus the arguments are considered not persuasive.
Applicant traverses the rejection of claims 8 and 9 over Suzuki et al. in view of Tanaka and Miyoshi et al. on the grounds that Tanaka and Miyoshi et al. do not remedy the deficiencies of Suzuki et al. As discussed above, applicant’s arguments in favor of claim 8 are moot as claim 8 has been canceled. With regard to claim 9, applicant’s arguments with respect to amended claim 1, which incorporates the limitations of claims 4 and 8, are not persuasive as the limitations are rendered obvious by Suzuki et al. in view of Tanaka and Onoe et al. Applicant does not present further arguments as to how the limitations of claim 6 overcome the prior art presented, and thus the arguments are considered not persuasive.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MORDECAI M LEAVITT whose telephone number is (571)272-6637. The examiner can normally be reached Monday-Friday 8AM-5PM.
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/MORDECAI M LEAVITT/Examiner, Art Unit 1742 /CHRISTINA A JOHNSON/Supervisory Patent Examiner, Art Unit 1742
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