Response to Amendment
This action is in response to applicants’ amendment of 23 June 2026. The amendments to claims 1 and 8 have overcome the 35 USC 112(a) rejection and the art rejections. However, upon further consideration, a new grounds of rejection is made in view of the amendment to claim 5 and a reference cited in the information disclosure statement of 16 June 2026.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 5 and 6 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 5 and 6 teach an oxide film configured to cover a surface a particle of the particles bodes that make up the magnetic metal particles. This wording means the fluid contains an oxide film is suitable to cover the particles; not that the individual particles have an oxide film thereon. In addition, the amendment makes it unclear if at least one of the particle bodies have a surface covered by the film or if all the bodies have a surface covered by the film. Thus the claims are indefinite. It is suggested to rewrite claim 5 so that it is clear that the fluid further comprises an oxide film covering a surface of each or at least one of the particles bodies.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-4 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over CN 2008-282929.
This reference teaches a magnetorheological fluid comprising a dispersion medium and magnetic particles dispersed in the medium and a vibration dampening device comprising the taught magnetorheological fluid. The taught magnetic particles are composed of iron based metal and have a coercive force of 5 Oe or less. Thus the taught particles meet the compositional requirements of claims 1 and 4. The taught particles have an average particle size of about 0.1-25 microns, which overlaps the range of claim 3 and a maximum size (99.9% of the particle have this size or less) of 50 microns or less. The ratio of maximum size, which include D90 size values, to average size, which corresponds to the claimed D50 size, is 2-500, which overlaps the range in claim 1. Product claims with numerical ranges which overlap prior art ranges were held to have been obvious under 35 USC 103. In re Wertheim 191 USPQ 90 (CCPA 1976); In re Malagari 182 USPQ 549 (CCPA 1974); In re Fields 134 USPQ 242 (CCPA 1962); In re Nehrenberg 126 USPQ 383 (CCPA 1960). Also see MPEP 2144.05. Since the taught fluid has the same composition has that set forth in claim 1 and an average particles size range and D90/D50 size range that overlaps those claimed, one of ordinary skill in the art in the article would expect the taught magnetic fluid to inherently have the properties set forth in claims 1 and 2 in the overlapping the size and size ratio ranges, absent any showing to the contrary. "Products of identical chemical composition cannot have mutually exclusive properties." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. Id. See MPEP 2112.01(II).
The taught device comprises a container configures to the store the fluid and a magnetic field forming, or generation, means, or unit, that applied a magnetic field to the fluid. This device has the same configuration as that of claim 9. The reference suggests and makes obvious the claimed magnetorheological fluid and device.
Allowable Subject Matter
Claim 8 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.
Claims 5 and 6 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action.
There is no teaching or suggestion in the art of record of a magnetorheological fluid comprising a dispersion medium and magnetic particles dispersed in the dispersion medium wherein the particles have a coercive force of 398 A/m or less and the precipitation inhibitor defined in claim 8; and wherein the fluid has a shear yield stress τA measured at a shear rate of 0.01/s after a magnetic field of 0.5 T is continuously applied for 480 second and the magnetic field is removed is less than 2.0 time a shear yield stress τB measured at a shear rate of 0.01/s before the magnetic field is applied.
There is no teaching or suggestion in the art of record of a magnetorheological fluid comprising a dispersion medium and oxide coated magnetic particles dispersed in the dispersion medium wherein the particles have a coercive force of 398 A/m or less; and wherein the fluid has a shear yield stress τA measured at a shear rate of 0.01/s after a magnetic field of 0.5 T is continuously applied for 480 second and the magnetic field is removed is less than 2.0 time a shear yield stress τB measured at a shear rate of 0.01/s before the magnetic field is applied.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to C. MELISSA KOSLOW whose telephone number is (571)272-1371. The examiner can normally be reached Mon-Tues:7:45-3:45 EST;Thurs-Fri:6:30-2:00EST; and Wed:7:45-2:00EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Johnson can be reached at 571-272-1177. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/C Melissa Koslow/Primary Examiner, Art Unit 1734
cmk
7/16/26
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