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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 October 15, 2025 has been entered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-5, 15, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over US 2005/0188788 of Ogi in view of JP 2007-084860 of Fujimoto further in view of CN107186218 of Wang.
Claim 1 requires a method of producing a silver powder comprising: a first surface smoothing step of causing fine silver particles having internal voids to mechanically collide with one another; a fine powder removal step of dispersing fine silver particles present after the first surface smoothing step using high-pressure airflow having a supply pressure of not less than 0.2 MPa and not more than 1.0 MPa while removing fine powder; and a second surface smoothing step of causing fine silver particles present after the fine powder removal step to mechanically collide with one another, wherein the first surface smoothing step is performed such that the cumulative power imparted per 1 kg of the silver powder is not less than 10 Wh/kg and not more than 300 Wh/kg.
Ogi discloses a silver powder and method for producing the same in the same field of endeavor as the claimed invention, that includes surface smoothing by putting silver powder into an apparatus that mechanically causes particles of the silver powder to collide with each other, Para[0027]. Ogi teaches a classification step, preferably an air classification step for separating particles by air flow which removes particles of a desired size, Para[0028]. Ogi also discloses that the input amount of the silver powder, the revolving speed and type of blades of the mixer or mill, and the processing time may be controlled to adjust the fluidization of particles and the smoothing of the shape of the surface due to collision. Ogi teaches that by this surface smoothing process, it is possible to smooth irregularities and angular portions on the surface of particles of the silver powder to decrease the viscosity of a conductive paste using the silver powder without substantially changing the particle diameter and particle size distribution of the silver powder. By this surface smoothing process, it is also possible to greatly improve the sensitivity of a photosensitive paste using the silver powder, Para[0027].
The fundamental equation linking power and rotational speed is known to be P = τω, where P is power, τ is torque, and ω is angular speed (or rotational/revolving speed). As such, it would be obvious to one of ordinary skill in the art that cumulative power imparted on the particle would be proportional to the rotation speed of the rotating blades. Therefore, based on the teachings of Ogi, it would be obvious to one of ordinary skill in the art to increase the speed of the rotating blade, thus increasing the cumulative power imparted on the particle to adequately smooth the shape of the surface of the resulting powder, and thus decreasing the viscosity of the conductive paste. It is also noted that in the instant specification, applicant states that the rotation speed of the rotating blade and the processing time in the first smoothing device 11 should be arbitrarily set such that power is imparted to the silver powder in the way in which it is claimed, Para[0045]. As with the Ogi reference, this similarly directly relates applicant’s cumulative power imparted limitation in claim 1 to the angular speed of the rotating blades.
While the prior art does not specify the numerical limitation for power imparted recited in claim 1, the prior art suggests a method involving the same steps using the same materials as that claimed. It therefore is a reasonable assumption that the resulting material would possess substantially the same physical properties in both instances, see MPEP 2112.01.
Ogi does not teach an airflow pressure or a second surface smoothing step as recited in claim 1.
Wang discloses a preparing method for modified ultrafine noble metal powder in a similar field of endeavor as the claimed invention. Wang teaches airflow pulverization and screening using an air pressure between 0.1 and 1.2 MPa, Para[0032]. This encompassed the claimed range of 0.2 to 1.0 MPa. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Wang discloses that this improves the dispersibility and tap density of the powder, Para[0013].
Fujimoto discloses a method for producing flake silver powder and flake silver powder produced by the method in the same field of endeavor as the claimed invention. Fujimoto teaches a pulverization treatment such that particles collide with each other in order to smooth the surface of the particles, and that the pulverization process can be repeated a plurality of times as necessary, and the level of the pulverization process can be arbitrarily selected according to the required quality, Para[0031].
Thus, it would be obvious to one of ordinary skill in the art to carry out a first smoothing step and a removal step disclosed in Ogi under the airlow supply pressure conditions taught in Wang to improve the dispersibility and tap density of the powder. It would also be an obvious variant of the method disclosed in Fujimoto to carry out a second smoothing step following the method set forth in Ogi in order to obtain particles of the required quality.
Therefore, Ogi in view of Fujimoto further in view of Wang reads on all limitations of claim 1.
Claim 2 further limits claim 1 by requiring a coarse powder classification step of removing coarse powder after the second surface smoothing step.
Ogi discloses a classification step for removing large silver particles, Para[0028]. Ogi teaches that any one of such commercially available apparatuses may be suitably chosen in accordance with the desired size of particles to be removed, the particle size distribution of particles after removing agglomerates, the classification speed, the yields of the silver powder and so forth, Para[0028]. Thus, it would be obvious to one of ordinary skill in the art to carry out the classification step disclosed in Ogi after the second surface smoothing step in order to remove the desired size particle. Therefore, Ogi in view of Fujimoto further in view of Wang reads on all limitations of claim 2.
Claim 3 further limits claim 1 by stating that the fine powder removal step includes: a separation and dispersion step of causing the fine silver particles to flow while continuously dispersing the fine silver particles using the high-pressure airflow and separating the fine powder from the fine silver particles; and a fine powder classification step of classifying the fine silver particles that have undergone the separation and dispersion step to remove the fine powder.
Ogi discloses that any number of apparatuses may be used in the classification step, Para[0028], including, for instance, those based on centrifugal force as well as combinations of such apparatuses suggest the use of an apparatus which will cause the silver particles to flow while continuously dispersing them using the airflow. Further the term "classification" implies that one is separating particles of different sizes, the smaller of which can be defined as "fine powder". Thus, Ogi in view of Wang further in view of Fujimoto reads on all limitations of claim 3.
Claim 4 further limits claim 1 by stating that the second surface smoothing step is continued until surfaces of the fine silver particles have an arithmetic average roughness of 3 nm or less in profile roughness measurement.
Fujimoto teaches that the pulverization process can be repeated a plurality of times as necessary, and the level of the pulverization process can be arbitrarily selected according to the required quality, Para[0031]. Therefore, it would be obvious to one of ordinary skill in the art to conduct the process conducted in Fujimoto until particles of the claimed quality were obtained.
While the prior art does not specify the numerical limitation for average roughness recited in claim 4, the prior art suggests a method involving the same steps using the same materials as that claimed. It therefore is a reasonable assumption that the resulting material would possess substantially the same physical properties in both instances, see MPEP 2112.01. Thus, Ogi in view of Fujimoto further in view of Wang reads on all limitations of claim 4.
Claim 5 further limits claim 1 by stating that silver powder present after the second surface smoothing step has an apparent density of 9.8 g/cm3 or less.
Fujimoto teaches that the pulverization process can be repeated a plurality of times as necessary, and the level of the pulverization process can be arbitrarily selected according to the required quality, Para[0031]. Therefore, it would be obvious to one of ordinary skill in the art to conduct the process conducted in Fujimoto until particles of the claimed quality were obtained.
While the prior art does not specify the numerical limitation for apparent density recited in claim 5, the prior art suggests a method involving the same steps using the same materials as that claimed. It therefore is a reasonable assumption that the resulting material would possess substantially the same physical properties in both instances, see MPEP 2112.01. Thus, Ogi in view of Fujimoto further in view of Wang reads on all limitations of claim 5.
Claim 15 further limits claim 1 by stating that the second surface smoothing step is continued until surfaces of the fine silver particles have an arithmetic average roughness of 4.9 nm or less in surface roughness measurement of a 500 nm x 500 nm area.
Fujimoto teaches that the pulverization process can be repeated a plurality of times as necessary, and the level of the pulverization process can be arbitrarily selected according to the required quality, Para[0031]. Therefore, it would be obvious to one of ordinary skill in the art to conduct the process conducted in Fujimoto until particles of the claimed quality were obtained.
While the prior art does not specify the numerical limitation for average roughness recited in claim 15, the prior art suggests a method involving the same steps using the same materials as that claimed. It therefore is a reasonable assumption that the resulting material would possess substantially the same physical properties in both instances, see MPEP 2112.01. Thus, Ogi in view of Fujimoto further in view of Wang reads on all limitations of claim 15.
Claim 16 further limits claim 1 by stating that the second surface smoothing step is performed such that the cumulative power imparted per 1 kg of the silver powder is 60 Wh/kg or more.
Fujimoto teaches that the pulverization process can be repeated a plurality of times as necessary, and the level of the pulverization process can be arbitrarily selected according to the required quality, Para[0031]. Therefore, it would be obvious to one of ordinary skill in the art to conduct the process conducted in Fujimoto until particles of the claimed quality were obtained.
While the prior art does not specify the numerical limitation for cumulative power imparted recited in claim 16, the prior art suggests a method involving the same steps using the same materials as that claimed. It therefore is a reasonable assumption that the resulting material would possess substantially the same physical properties in both instances, see MPEP 2112.01. Thus, Ogi in view of Fujimot further in view of Wang reads on all limitations of claim 16.
Response to Arguments
Applicant’s remarks filed October 15, 2025 have been fully considered, with the following effect:
With regard to the prior art rejections, applicant asserts that the prior art previously applied (Ogi, Fujimoto, Wang) does not teach a cumulative power imparted per 1 kg of silver powder in the range of 10 Wh/kg to 300 Wh/kg. In response, the examiner submits that the prior art previously applied, specifically Ogi, teaches adjustment of the rotation speed of the blade resulting in the optimization of the cumulative power imparted, rendering the claimed range of cumulative power obvious to one of ordinary skill in the art, for reasons detailed in the grounds of rejection above.
Applicant also asserts that the tap density of Example 1 is an unexpected result because it is significantly higher than the tap density of Comparative Example 2. Applicant asserts that this demonstrates that applying the cumulative power more than 300 Wh/kg, which falls outside the claimed range, in a single smoothing step, does not lead to the desired effect. In response, the examiner asserts that both Example 1 and Comparative Example 2 have a cumulative power imparted above 300 Wh/kg, which falls outside the claimed range. Therefore, these examples cannot be used to show unexpected results of the claimed invention as they fall outside of its scope.
Examiner also submits that the prior art previously applied, specifically Ogi, teaches several examples showing an increase in tap density that results from the disclosed surface smoothing process. In paragraphs [0047] – [0051], Ogi discloses one example in which the smoothing process is carried out, and another example where the pulverization is carried out by a different means. The example that carried out the smoothing process achieved a tap density of 5.4 g/ml, Para[0048], while the non-smoothing example achieved a tap density of 4.7 g/ml, Para[0051]. This shows that the significantly higher tap density achieved through the surface smoothing process would be obvious to one of ordinary skill in the art, and therefore is not an unexpected result.
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 JACOB BENJAMIN STILES whose telephone number is (571)272-0598. The examiner can normally be reached Monday-Friday 7:30am - 5:00pm.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/JACOB BENJAMIN STILES/ Examiner, Art Unit 1733