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 .
Disposition of Claims
Claims 1-19 are pending in the application. Claims 5-11 are withdrawn from consideration due to Applicant’s elections.
Amendments to claims 1-8, and new claims 12-19, filed on 9/2/2025, have been entered in the above-identified application.
Claim Rejections - 35 USC § 102 or 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 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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed 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.
Claim(s) 1 is/are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Gan (CN 110079266 A1, see attachment).
Regarding claim 1, Gan teaches a high-thermal-conductivity conductive adhesive prepared from nano-silver modified carbon nanotubes (Abstract). According to a method, carbon nanotubes modified with nano-silver are added to a silver adhesive, heat conducting bridge linking is formed among micro-silver particles, nano-silver on surfaces of the carbon nanotubes and silver particles are sintered and linked, a large number of heat conducting paths are established, the carrier transport potential barrier among filler is reduced, and the transport efficiency of phonons and electrons among filler interfaces is substantially improved (Abstract). The silver powder is composed of one or two kinds of flakes and spherical silver powders (page 5, lines 3-4).
The SEM image of a highly thermally conductive paste prepared in Example 1 is shown in FIGS. 2 and 3 (page 6, lines 34-35). Gan teaches that it can be seen from Fig. 2 that the nano-silver on the surface of the carbon nanotube has a low-temperature sintering activity and can be sintered with silver powder (page 6, lines 36-38). The silver powder is in the form of a sheet (flakes, as claimed) and has an average particle diameter of 4.0 to 6.1 µm (page 6, lines 22-25). The examiner notes that, in FIGS. 2-3, contours of the individual silver flakes are microscopically visually confirmable within the sintered layer, and it can be seen that the sintered layer includes spaces surrounded by the silver flakes.
Claim 1 includes a product-by-process limitation. The product being claimed appears to be the same as or obvious over the prior art product, in which case differences in process are not considered to impart patentability. Thus, the burden is shifted to Applicant to show that any differences in process would result in a difference between the claimed product and the prior art product.
Claim(s) 1-4 is/are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Zhang et al. (“Metallic conductivity transition of carbon nanotube yarns coated with silver particles,” attached 6/17/2025).
Regarding claims 1-3, Zhang teaches that dry spun carbon nanotube yarns made from vertically aligned multiwalled carbon nanotube forests possess high mechanical strength and behave like semiconductors with electrical conductivity of the order of 4 × 104 S m−1 (Abstract). Coating a submicron-thick film of silver particle-filled polymer on the surface increased the electrical conductivity of the carbon nanotube yarn by 60-fold without significantly sacrificing its mechanical strength (Abstract). Acetone-pretreated CNT yarns were immersed in an as received conducting silver paste or in its dilutions in dimethyformimide (DMF) and then passed through a furnace set to 120 °C to remove reagents and cure the polymers (Section 2.3). The backscattered SEM micrograph in figure 5(b) shows that silver particles overlapped with each other and formed conducting paths (a sintered layer as claimed) (Section 3.4). Energy-dispersive x-ray spectroscopy confirmed that elemental composition of the bright white particles was principally silver (Section 3.4, and FIGS. 2, 5 and 7). The silver particles were thin plates (estimated thickness 0.1–0.2 µm) with surface sizes from submicron to about 5 µm across (silver flakes as claimed) (Section 3.4, and FIGS. 2, 5 and 7). Because polymer solutions do not infiltrate CNT yarns very well [17], the final composite yarn has a dry pure CNT core and a thin polymer sheath filled with silver particles (Section 3.6). CNTs in the spinnable forests had an outer diameter of approximately 10 nm, an inner diameter of about 4 nm, and a length of approximately 350 µm (a plurality of carbon nanotubes as claimed in claim 3) (Section 2.1, and FIGS. 2, 5 and 7).
The examiner notes that, in FIGS. 5(a), 5(b) and 7(a), contours of the individual silver flakes are microscopically visually confirmable within the sintered layer, and it can be seen that the sintered layer includes spaces surrounded by the silver flakes.
Claims 1-3 include a product-by-process limitation. The product being claimed appears to be the same as or obvious over the prior art product, in which case differences in process are not considered to impart patentability. Thus, the burden is shifted to Applicant to show that any differences in process would result in a difference between the claimed product and the prior art product.
Regarding claim 4, Zhang remains similarly as applied above to claims 1-3.
Zhang further teaches that CNTs in the spinnable forests had an outer diameter of approximately 10 nm, an inner diameter of about 4 nm, and a length of approximately 350 µm (Section 2.1). In the production of CNT yarns, the forests were attached to a rotating spindle and the CNTs were drawn from the CNT forests in the form of a continuous web (wherein the yarn includes a plurality of filaments, and each of the filaments includes a carbon nanotube, as claimed) (Section 2.1 and FIGS. 2, 5 and 7).
Zhang does not explicitly disclose a second sintered layer attached to a surface of the yarn and a first sintered layer attached to a surface of the carbon nanotube, wherein each of the first sintered layer and the second sintered layer includes a plurality of silver flakes.
However, Zhang teaches that energy-dispersive x-ray spectroscopy confirmed that elemental composition of the bright white particles was principally silver (Section 3.4, and FIGS. 2, 5 and 7). The silver particles were thin plates (estimated thickness 0.1–0.2 µm) with surface sizes from submicron to about 5 µm across (Section 3.4). The examiner notes that individual patches of silver can be seen in FIG. 7 that would each correspond to sintered layers made up of overlapping silver plates (i.e., silver flakes).
It would have been obvious to one having ordinary skill in the art prior to the effective filing date of the invention to have expected that the silver patches (i.e., the sintered layers) on the surface of the carbon nanotube yarns would comprise a plurality of silver plates (flakes) because Zhang teaches that the silver plates overlap with each other and that the silver plates range from submicron surface sizes up to 5 µm across, and because the sizes of some of the silver patches shown in Zhang’s FIG. 7 are on the order of 20 to 50 microns across (see Section 3.4).
Claim Rejections - 35 USC § 103
Claim(s) 1-4 and 12-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Huynh (US 2019/0218099 A1) in view of Lee et al. (US 2016/0001362 A1).
Regarding claims 1-2, Huynh teaches wherein nanofiber sheet assemblies include at least one nanofiber sheet and at least one nanofiber grid or web that is used to improve the physical durability of the nanofiber sheet within the assembly (Abstract). The terms "nanofiber" and "carbon nanotube" encompass both single walled carbon nanotubes and/or multi-walled carbon nanotubes in which carbon atoms are linked together to form a cylindrical structure ([0147]-[0148]). Huynh teaches techniques that include the use of solutions of solvents that can produce nanofiber grids having selectable bundle diameters and gap widths ([0103]).
Optionally, nanoparticles may be added 312 to a solution of water and an organic solvent ([0116]). Illustrative examples of nanoparticles that can be added 312 to the solution include nano flakes, nano rods, and spherical nano particles of any of a variety of metals including, but not limited to silver, copper, gold, iron, nickel, neodymium, platinum, palladium, graphene, graphene oxide, fullerenes, small organic molecules, polymers, oligomers, ceramic sol gel precursors, among others ([0116] and end of [0129]). In some examples, in situ reactions (including those involving strong acids, bases, and/or temperatures up to 350° C.) can be performed on and/or within nanofiber sheets to form coatings and/or nanoparticles on and/or within the nanofiber sheet (a sintered layer attached to a surface of the carbon nanotube(s), wherein the sintered layer includes a plurality of silver flakes, and wherein the silver flakes are bonded to each other by sintering, as claimed) ([0117]; also see [0109] and [0131]). The examiner notes that silver flakes would retain their flake shape in the disclosed temperature range of up to 350° C. (In addition, as applied below, Lee teaches a sintered layer in which silver flakes retain their flake shape).
Huynh does not explicitly disclose wherein the sintered layer includes spaces surrounded by the silver flakes.
However, Lee teaches fine particles 2 that are flake-like (Abstract and FIG. 1). A main component of the fine particles 2 is an electrically conductive metal (Abstract). A representative metal is silver (Abstract). The examiner notes that Lee teaches an electrically conductive paste comprising the fine particles ([0011]). With the paste, sintering is achieved through heating for a short period of time ([0015]). With the paste, sintering is achieved through heating at a low temperature ([0015]). In a pattern after sintering, the fine particles overlap with each other with a large contact surface area ([0016]). Thus, the pattern can easily conduct electricity ([0016]). The fine particles are also superior in electrical conductivity ([0016]). FIGS. 2 and 3 are microscope pictures showing fine particles according to Example 1 ([0018]-[0019]). The examiner notes that, in FIGS. 2 and 3, contours of the individual silver flakes are microscopically visually confirmable within the sintered layer, and it can be seen that the sintered layer includes spaces surrounded by the silver flakes as claimed.
It would have been obvious to one having ordinary skill in the art prior to the effective filing date of the invention to have applied the particles of Huynh as a sintered paste of fine silver flake-like particles having the structure shown by Lee in FIGS. 2 and 3, including spaces surrounded by the silver flakes, in order to provide a pattern of conductive particles that can easily conduct electricity due to the existence of a large overlap contact surface area, thus providing both superior electrical conductivity and thermal conductivity, as suggested by Lee (Abstract and [0014]-[0015]).
Claims 1-2 include a product-by-process limitation. The product being claimed appears to be the same as or obvious over the prior art product, in which case differences in process are not considered to impart patentability. Thus, the burden is shifted to Applicant to show that any differences in process would result in a difference between the claimed product and the prior art product.
Regarding claim 3, Huynh remains similarly as applied above to claims 1-2. With respect to a yarn as claimed, Huynh teaches that in other techniques of the disclosure, a nanofiber assembly can be fabricated by "scoring" lines in a nanofiber forest or strips in the nanofiber forest that cannot be spun into nanofiber yarn ([0092]). This scoring can be performed by, for example, using a laser or a mechanical or thermal treatment of the forest. These "unspinnable" regions separate regions of nanofiber forest that can be spun into nanofiber yarns ([0092]). This technique can be used to control width of the nanofiber bundles resulting from the spinnable strips as well as the spacing (or "pitch") between nano fiber bundles in a nanofiber assembly ([0092]).
Regarding claim 4, Huynh remains similarly as applied above to claims 1-3, teaching a yarn comprising filaments each including nanofibers (i.e., carbon nanotubes). Huynh does not explicitly disclose a second sintered layer attached to a surface of the yarn and a first sintered layer attached to a surface of the carbon nanotube as claimed. However, as applied above to claims 1-2, Huynh teaches that, in some examples, in situ reactions (including those involving strong acids, bases, and/or temperatures up to 350° C.) can be performed on and/or within nanofiber sheets to form coatings and/or nanoparticles on and/or within the nanofiber sheet ([0117]). It would have been obvious to one having ordinary skill in the art prior to the effective filing date of the invention to have provided the coatings and/or nanoparticles on and/or within the nanofiber yarns of the sheet in order to provide coatings and/or nanoparticles distributed on and/or within the nanofiber sheet as desired ([0117]).
Regarding claims 12-19, Lee teaches that the structure of the metal is monocrystalline (Abstract). Preferably, a median size (D50) of the powder is not smaller than 0.1 μm but not larger than 20 μm ([0010]). Preferably, an aspect ratio (D50/Tave) of the powder is not lower than 20 but not higher than 1000 ([0010]). An arithmetical mean roughness Ra of the surface of the fine particles 2 is not larger than 10 nm (Abstract).
Response to Arguments
Applicant's arguments filed 9/2/2025 have been fully considered but they are not persuasive.
Applicant contends that Zhang cures polymers at 120 °C, without true sintering or flake shape retention.
Regarding this contention, Zhang teaches that the network of silver particles in the thin silver/adhesive film deposited on the yarn surface must have formed electrical percolation paths (page 4, end of second par. in Section 3.3). The metallic conducting elements (silver particles) of these paths are either making physical contact among themselves or are separated by very small distances across which electrons can tunnel [11] (page 4, end of second par. in Section 3.3). The backscattered SEM micrograph in figure 5(b) shows that silver particles overlapped with each other and formed conducting paths (page 4, first par. in Section 3.4). Energy-dispersive x-ray spectroscopy confirmed that elemental composition of the bright white particles was principally silver (page 4, first par. in Section 3.4). Figure 7 presents four SEM images of treated CNT yarns with silver contents around the percolation threshold (page 5, second to last par. on right). At 10.9 wt% silver content, we can observe many contacts between silver platelets (same par. and FIG. 7a). The examiner notes that the formation of these interfaces between the silver particles in the conducting shell of the conductor-insulator mixture on the CNT yarn, which form a network of electrical percolation paths, would meet the claimed limitation “the silver flakes are bonded to each other by sintering.”
Applicant contends that Huynh describes coatings formed via in situ reactions up to 350 °C, with no teaching of sintering or preserved morphology.
Regarding this contention, Huynh teaches that an aerosol of the silver nitrate solution can be contacted with the nanofiber sheet, depositing the silver nitrate on the nanofibers ([0117]). Silver nitrate can then be reacted in situ to produce, for example, metallic silver ([0117]). In some other examples, in situ reactions, including those involving strong acids, bases, and/or temperatures up to 350° C., can be performed on and/or within nanofiber sheets to form coatings and/or nanoparticles on and/or within the nanofiber sheet ([0117]). The examiner notes that a coherent mass of the nanoparticles can therefore be formed by heating without melting, which would meet the claimed limitation “the silver flakes are bonded to each other by sintering.” The examiner also notes that silver flakes would retain their flake shape in the disclosed temperature range of up to 350° C. In addition, as applied above, Lee teaches wherein, with a paste comprising fine flake-like particles of silver, sintering is achieved through heating for a short period of time and through heating at a low temperature (Abstract, [0011] and [0015]).
Applicant contends that Gan mentions sintering in a resin-based adhesive for thermal conduction, but does not disclose flake contour retention or internal porosity, and suggests more complete fusion.
Regarding this contention, Gan teaches that an SEM image of a highly thermally conductive paste prepared in Example 1 is shown in FIGS. 2 and 3 (page 6, lines 34-35). The examiner notes that, in FIGS. 2-3, contours of the individual silver flakes are microscopically visually confirmable within the sintered layer, and it can be seen that the sintered layer includes spaces surrounded by the silver flakes, as claimed.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 10,446,518 B2 teaches a sinterable bonding material comprising a silver filler and resin particles, wherein the silver filler comprises a flake-shaped filler having an arithmetic average roughness (Ra) of 10 nm or less, preferably a central particle diameter (D50) of 0.05 μm or more and 20 µm or less, and preferably an aspect ratio of preferably 20 or more and 1000 or less (Abstract, cols. 4-5, lines 66-9, and col. 5 lines 30-36).
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 Kevin Worrell whose telephone number is (571)270-7728. The examiner can normally be reached Monday-Friday.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Marla McConnell can be reached at 571-270-7692. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Kevin Worrell/Examiner, Art Unit 1789
/MARLA D MCCONNELL/Supervisory Patent Examiner, Art Unit 1789
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