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 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.
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 18-26, 37, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Qian et al. (CN 101696328) in view of Laliena Iranzo et al. (WO 2019/122957) as evidenced by China GB 9439 HT300 Gray Cast Iron, https://www.iron-foundry.com/China-GB-9439-HT300-gray-cast-iron.html, accessed 2025. Note: A machine translation is being used for CN 101696328.
Considering Claims 18 and 19: Qian et al. teaches a coated iron work piece comprising a coating comprising a graphite material having a grain size below 140 mesh and a binder that is sodium silicate (¶0004) and a substrate that is HT 300 cast iron (Table). The evidentiary reference shows that HT 300 has a carbon content of 2.8-3.2%, a silicon content below 5 weight percent and a manganese content below 3 weight percent.
Qian et al. does not specify that the graphite is a nanographite. However, Laliena Iranzo et al. teaches using a coating comprising nanographite in the form of graphene nanoplatelets having a lateral size of 1 to 60 microns and sodium silicate binder to a iron substrate (3:12-18). Qian et al. and Laliena Iranzo et al. are analogous art as they are concerned with the same field of endeavor, namely iron substrate treatments. It would have been obvious to a person of ordinary skill in the art to have used a nanographite in the coating of Qian et al., as in Laliena Iranzo et al., and the motivation to do so would have been, as Laliena Iranzo et al. suggests, to reduce decarburization during the heating of the substrate (3:12-18).
Considering Claim 20, 21, and 37: Qian et al. and Laliena Iranzo et al. are silent towards the width and thickness of the nanographite. Laliena Iranzo et al. teaches that the size of the graphite controls the dispersion in the binder and the path of decarburization (3:19-26), and thus the size would be a result effective variable. It would have been obvious to a person of ordinary skill in the art to have optimized the width and thickness through routine experimentation, and the motivation to do so would have been, as Laliena Iranzo et al. suggests, to control the dispersion and decarburization properties of the graphite.
Considering Claims 22-24: Qian et al. teaches the graphite and sodium silicate as being present in a ratio of 1:3-7, and thus the amount of graphite is 14-25% and the amount of silicate is 75 to 86% (¶0004). It would have been obvious to a person of ordinary skill in the art to have selected the amount of graphite and sodium silicate in the overlapping portion of the claimed ranges, and the motivation to do so would have been, as Qian et al. suggests, to control the decarburization of the coating.
Considering Claim 25: Qian et al. is silent towards the thickness of the coating. However, Laliena Iranzo et al. teaches the coating as having a thickness of 10 to 250 microns (4:8-10). It would have been obvious to a person of ordinary skill in the art to have used the thickness of Laliena Iranzo et al. in the coating of Qian et al., and the motivation to do so would have been, it is a suitable thickness to provide the desired protection to the surface.
Considering Claims 26 and 38: Qian et al. does not teach the claimed additives. However, Laliena Iranzo et al. teaches adding alumina/aluminum oxide to the silicate binder (4:12-17). It would have been obvious to a person of ordinary skill in the art to have added alumina to the binder of Qian et al., as in Laliena Iranzo et al., and the motivation to do so would have been, as Laliena Iranzo et al. suggests, to increase the adhesion to the steel substrate (4:12-17).
Claims 26 and 36 are rejected under 35 U.S.C. 103 as being unpatentable over Qian et al. (CN 101696328) in view of Laliena Iranzo et al. (WO 2019/122957) as evidenced by China GB 9439 HT300 Gray Cast Iron, https://www.iron-foundry.com/China-GB-9439-HT300-gray-cast-iron.html, accessed 2025 as applied to claim 18 above, and further in view of Guo et al. (CN 110922797).
Considering Claims 26 and 36: Qian et al. and Laliena Iranzo et al. collectively teach the coated substrate of claim 18 as shown above.
Qian et al. does not teach the claimed additives. However, Guo et al. teaches adding zinc oxide, and magnesium oxide to a graphene coating for metal substrates (Abstract). Guo et al. teaches the coating as comprising 15 to 25 parts of sodium silicate, 2 to 8 parts of zinc oxide, 1 to 5 parts of magnesium oxide, and 15 to 25 parts of graphene (Abstract). As such, the amount of zinc oxide is 2/57 to 8/31, or 3.5 to 26% by weight. Qian et al. and Guo et al. are analogous art as they are concerned with the same field of endeavor, namely coatings for metal substrates. It would have been obvious to a person of ordinary skill in the art to have added the zinc oxide and magnesium oxide of Guo et al. to the coating of Qian et al., and the motivation to do so would have been, as Guo et al. suggests, to provide corrosion resistance to the surface (Abstract).
Response to Arguments
Applicant's arguments filed February 17, 2026 have been fully considered but they are not persuasive, because:
A) The applicant’s argument that Laliena Iranzo et al. teaches applying the coating to a different cast iron substrate with a different composition than claimed is not persuasive. The rationale to support a conclusion that the claim would have been obvious is that a method of enhancing a particular class of devices (methods, or products) has been made part of the ordinary capabilities of one skilled in the art based upon the teaching of such improvement in other situations. One of ordinary skill in the art would have been capable of applying this known method of enhancement to a "base" device (method, or product) in the prior art and the results would have been predictable to one of ordinary skill in the art. "It's enough … to show that there was a known problem … in the art, that [another reference] … helped address that issue, and that combining the teachings of [the two references] wasn't beyond the skill of an ordinary artisan. Nothing more is required to show a motivation to combine under KSR." See Intel Corp. v. PACT XPP Schweiz AG, 61 F.4th 1373, 1380-81, 2023 USPQ2d 297 (Fed. Cir. 2023) (finding that both prior art references "address the same problem and that [the secondary reference’s] cache was a known way to address that problem is precisely the reason that there's a motivation to combine under KSR and our precedent.").
As the coating of Laliena Iranzo et al. is in an improvement with a different cast iron substrate, it would have been obvious to apply the coating to different substrates, including the substrate of Qian et al.
B) The applicant’s argument that Laliena Iranzo et al. does not specifically teach that the width and thickness of the nanographite is a result effective variable is not persuasive. Laliena Iranzo et al. teaches that the size of the graphite controls the dispersion in the binder and the path of decarburization (3:19-26), and thus the size would be a result effective variable. It would have been obvious to a person of ordinary skill in the art to have optimized the width and thickness through routine experimentation, and the motivation to do so would have been, as Laliena Iranzo et al. suggests, to control the dispersion and decarburization properties of the graphite.
While Laliena Iranzo et al. does not specifically mention the width and thickness of the nanographite, these factors would influence the dispersion and the bath of decarburization in a similar way as the lateral size. "A person of ordinary skill in the art is also a person of ordinary creativity, not an automaton." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 421, 82 USPQ2d 1385, 1397 (2007). "[I]n many cases a person of ordinary skill will be able to fit the teachings of multiple patents together like pieces of a puzzle." Id. at 420, 82 USPQ2d 1397. Office personnel may also take into account "the inferences and creative steps that a person of ordinary skill in the art would employ." Id. at 418, 82 USPQ2d at 1396.
C) In response to applicant's argument that Qian et al. and Guo are nonanalogous art, it has been held that a prior art reference must either be in the field of the inventor’s endeavor or, if not, then be reasonably pertinent to the particular problem with which the inventor was concerned, in order to be relied upon as a basis for rejection of the claimed invention. See In re Oetiker, 977 F.2d 1443, 24 USPQ2d 1443 (Fed. Cir. 1992). In this case, Qian et al. and Guo et al. are analogous art as they are concerned with the same field of endeavor, namely coatings for metal substrates.
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.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LIAM J HEINCER whose telephone number is (571)270-3297. The examiner can normally be reached M-F 7:30-5:00.
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/LIAM J HEINCER/ Primary Examiner, Art Unit 1767