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, 11-13 and 17 are amended in view of applicant’s response filed 4/1/2026. Claims 4, 6 and 14 are canceled. Therefore, claims 1-3, 5, 7-13 and 15-20 are currently under examination.
Status of Previous Rejections
The rejection of claims 3-4 and 12-14 under 35 U.S.C. 112(b) or 35 U.S.C. (pre-AIA ), second paragraph, is withdrawn in view of applicant’s claim amendment in the response filed 4/1/2026.
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.
Claim(s) 1-3 and 7-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN103820774A(CN774), and further in view of “SOLAGUMTM: New Thickeners and Emulsifer for Industrial Applications”, SEPPIC, Pages 1-24, July 2022(SOLAGUM).
CN774 teaches a cleaning/pickling and passivating composition comprising 20-40 parts of passivant such as nitric acid, 20-40 parts of inorganic filler such as magnesium fluoride, and 0.5-2 parts of thickening agent, and 10-35 parts of a viscosity regulator such as water [0007, 0012-0013 and 0015-0016].
Regarding claims 1-3 and 7-8, the cleaning/picking passivation composition as taught by CN774 comprises the magnesium fluoride salt and nitric acid in an aqueous medium as claimed. However, CN774 does not explicitly teach that the thickening agent is a water-swellable crosslinked polymer as claimed.
SOLAGUM teaches SOLAGUM SH 210(i.e. a water-swellable crosslinked copolymer) as a good thickener for highly acid aqueous solutions such as nitric acid(page 9, section 5.1). SOLAGUM further teaches that SOLAGUM SH 210 is stable upon aging(pages 9-10). Fig. 5 of SOLAGUM shows that viscosity of a solution comprising 12 wt% of SOLAGUM SH 210 in 10% nitric acid remains the same after 3 months at 20°C.
Therefore, it would have been obvious to one of ordinary skill in the art to have incorporated the 12wt% of SOLAGUM SH 210 into the cleaning/pickling and passivating composition of CN774 in order to achieve the desired thickening of the solution while maintaining viscosity stability over a long period of time as taught by SOLAGUM.
Additionally, CN774 further teaches that the composition is formed by adding magnesium nitrate hexahydrate, and hydrofluoric acid as claimed [0031,0033].
Furthermore, the claimed composition is a product-by-process claim. The amended limitation “wherein the magnesium fluoride salt, and nitric acid and/or a nitrate salt are formed in situ by reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid” are directed to a method of how the claimed magnesium fluoride is made. It is well settled that a product-by-process claim defines a product, and that when the prior art discloses a product substantially the same as that being claimed, the burden falls upon the applicant to show that any process steps associated therewith results in a product materially different from that disclosed in the prior art. See In re Thorpe, (227 USPQ 964), In re Brown, (173 USPQ 685), In re Fessman, (180 USPQ 524) and MPEP 2113. Since the cleaning/pickling and passivation composition of CN774 in view of SOLAGUM comprises the claimed magnesium fluoride salt and nitric acid and/or nitrate salt, the burden falls upon the applicant to show that the claimed “in situ reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid” results in a composition materially different from the cleaning/pickling and passivation composition of CN774 in view of SOLAGUM.
Regarding claim 9, it would have been well within the skills of an ordinary artisan to have stored the cleaning/pickling and passivation composition in a container and use in multiple applications with expected success.
Regarding claim 10, CN774 further teaches that it is widely known that the cleaning passivation composition is typically used by a spraying method[0002].
Claim(s) 5, 11-13, 15-16 and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN774 in view of SOLAGUM, and further in view of Vitomir US 10,280,515 B1(Vitomir).
The teachings of CN774 in view of SOLAGUM are discussed in section 5 above.
However, CN774 in view of SOLAGUM do not explicitly teach the additional sulfamic acid and/or calcined alumina.
Vitomir teaches a pickling and passivation composition comprising magnesium fluoride salts of hydrofluoric acid and nitric acid (col. 2 lines 26-31, 34-55) and a thickener (col. 3 lines 10-13, col. 6 lines 10-17). Vitomir further teaches that the pickling and passivation composition can additionally include sulfamic acid to help prevent the dissociation of the magnesium fluoride salt, which substantially reduces the formation of hydrofluoric acid(col. 2 lines 56-60).
Regarding claim 5, it would have been obvious to one of ordinary skill in the art to have incorporated the sulfamic acid as taught by Vitomir into the cleaning/pickling and passivation composition of CN774 in view of SOLAGUM in order to help prevent the dissociation of the magnesium fluoride salt, which substantially reduces the formation of hydrofluoric acid as taught by Vitomir.
Regarding claims 11-13 and 15-16, CN774 further teaches a method of preparing this cleaning/pickling and passivation composition, comprising
adding magnesium nitrate hexahydrate in water[0031];
adding hydrofluoric acid [0033], which would have reacted with magnesium nitrate hexahydrate to form magnesium fluoride precipitate and nitric acid.
Additionally, CN774 in view of SOLAGUM teaches the addition of SOLAGUM SH 210 thickener(i.e. a water-swellable crosslinked copolymer) to thicken and stabilize the viscosity of the highly acidic cleaning/pickling and passivation composition.
However, CN774 in view of SOLAGUM do not teach the claimed magnesium nitrate hexahydrate amount and that the magnesium nitrate hexahydrate is in molar excess relative to hydrofluoric acid as claimed.
Vitomir additionally teaches that the magnesium fluoride is prepared by an in situ reaction of magnesium nitrate and hydrofluoric acid wherein magnesium nitrate is 15-50 wt% of the coating composition(col. 2 lines 54-55, col. 5 lines 21-22) and magnesium nitrate is in molar excess to hydrofluoric acid(col. 4 lines 10-48, col. 5 lines 1-37).
Therefore, it would have been obvious to one of ordinary skill in the art to have incorporated 15-50 wt% magnesium nitrate and the in situ reaction of magnesium nitrate and hydrofluoric acid to form magnesium fluoride, wherein magnesium nitrate is in molar excess to hydrofluoric acid, as taught by Vitomir into the process of CN774 in view of SOLAGUM in order to prevent magnesium fluoride from dissociating into hydrofluoric acid and to promote passivation of stainless steel to reduce the risk of corrosion as taught by Vitomir(col. 4 lines 29-39, col. 5 lines 31-37).
Furthermore, the amount of magnesium nitrate as taught by CN774 in view of SOLAGUM and Vitomir overlaps the claimed amount of magnesium nitrate hexahydrate. Therefore, a prima facie case of obviousness exists. See MPEP 2144.05(II). The selection of claimed amount of magnesium nitrate from the teachings of CN774 in view of SOLAGUM and Vitomir would have been obvious to one of ordinary skill in the art since CN774 in view of SOLAGUM and Vitomir teach the same utilities in their disclosed magnesium nitrate concentration.
Regarding claim 18, CN774 further teaches applying the cleaning/picking and passivation solution to a surface of a stainless steel as claimed.
Regarding claim 19, CN774 further teaches that its cleaning and passivation composition can be applied to remove the scar of an argon arc welding[0035], which implies that the stainless steel surface comprises a weld.
Regarding claim 20, CN774 further teaches that it is widely known that the cleaning passivation composition is typically used by a spraying method[0002].
Allowable Subject Matter
Claim 17 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Prior art of record does not teach or fairly suggest, either alone or in combination, the claimed method of preparing a pickling and passivation composition comprising dissolving the claimed amount of magnesium nitrate hexahydrate, adding claimed amounts of hydrofluoric acid and water-swellable crosslinked copolymer.
Response to Arguments
Applicant's arguments filed 4/1/2026 have been fully considered but they are not persuasive.
In the remarks, applicant argues that CN774 in view of SOLAGUM do not teach claimed the magnesium fluoride salt, and nitric acid and/or a nitrate salt are formed in situ by reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid.
With respect to product-by-process claim 1, applicant’s argument is not persuasive. The amended limitation “wherein the magnesium fluoride salt, and nitric acid and/or a nitrate salt are formed in situ by reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid” are directed to a method of how the claimed magnesium fluoride is made. It is well settled that a product-by-process claim defines a product, and that when the prior art discloses a product substantially the same as that being claimed, the burden falls upon the applicant to show that any process steps associated therewith results in a product materially different from that disclosed in the prior art. See In re Thorpe, (227 USPQ 964), In re Brown, (173 USPQ 685), In re Fessman, (180 USPQ 524) and MPEP 2113. Since the cleaning/pickling and passivation composition of CN774 in view of SOLAGUM comprises the claimed magnesium fluoride salt and nitric acid and/or nitrate salt, the burden falls upon the applicant to show that the claimed “in situ reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid” results in a composition materially different from the cleaning/pickling and passivation composition of CN774 in view of SOLAGUM.
With respect to process claim 11, the amended “in situ reaction of magnesium nitrate hexahydrate in molar excess with hydrofluoric acid” is addressed in the rejection ground of CN774 in view of SOLAGUM and Vitomir in section 6 above.
Applicant further argues that CN 776 does not teach a composition free of hydrofluoric acid. However, applicant’s argument is not commensurate with the scope of the claims since the instant claims do not exclude the presence of hydrofluoric acid.
Applicant further argues that CN774 teaches direct application of coating composition to stainless steel immediately after it is prepared, and does not teach packaging or storing the composition, and the passivation paste of CN774 in view of SOLAGUM would not be suitable for extended storage and usability.
The examiner does not find applicant’s argument convincing because the cleaning/pickling and passivating composition of CN774 in view of SOLAGUM or CN774 in view of SOLAGUM and Vitomir is significantly similar to the claimed coating composition. One of ordinary skill in the art would have expected the same type of stability performance as claimed cleaning/pickling and passivating composition, absent persuasive evidence to the contrary. Additionally, applicant is reminded that one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). See MPEP 2145 (IV). In this case, the rejection ground is based on CN774 in view of SOLAGUM or CN774 in view of SOLAGUM and Vitomir, wherein SOLAGUM is incorporated into the rejection grounds for its teaching of adding water-swellable crosslinked copolymer to increase coating stability. Therefore, the examiner maintains that the rejection grounds are proper, absent persuasive evidence to the contrary.
Regarding claims 5 and 15, applicant further argues that Vitomir does not teach calcined alumina or formation of NO2 and sulfuric acid.
The examiner does not find applicant’s argument convincing because claims 5 and 15 recites “adding sulfamic acid and/or calcinated alumina”, which indicates that calcinated alumina is an optional ingredient in the cleaning/pickling and passivating composition. Therefore, the examiner maintains that the sulfamic acid present in the cleaning/pickling and passivating composition of CN774 in view of SOLAGUM and Vitomir is sufficient to read on the claims 5 and 15. Additionally, since the composition of CN774 in view of SOLAGUM and Vitomir contains sulfamic acid, nitric acid and magnesium nitrate, one of ordinary skill in the art would have expected that the nitric acid and the sulfamic acid to react and form NO2 and sulfuric acid with expected success as recited in claim 15.
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 LOIS L ZHENG whose telephone number is (571)272-1248. The examiner can normally be reached Mon-Fri 8:15-4:45.
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LOIS ZHENG
Primary Examiner
Art Unit 1733
/LOIS L ZHENG/Primary Examiner, Art Unit 1733
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