DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 March 30th, 2026 has been entered.
Response to Amendment
Applicant's amendment filed March 30th, 2026 has been entered. Claims 1, 11, and 17-18 have been amended. Claim 5 has been cancelled.
The Section 103 rejections over Bai as the primary reference have been withdrawn due to Applicant’s amendment. However, upon further consideration, a new ground(s) of rejection has been made.
The Section 103 rejections over Mishiro as the primary reference have been withdrawn due to Applicant’s amendment. However, upon further consideration, a new ground(s) of rejection has been made.
The Section 103 rejections over Gao as the primary reference have been withdrawn due to Applicant’s amendment and arguments being persuasive.
Response to Arguments
Applicant’s arguments filed March 30th, 2026 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. However, the Examiner wishes to address a few points.
In response to Applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Applicant argues that Bai does not teach the use of pyrolytic graphite sheets because of a semantics issue. The Examiner disagrees.
Bai teaches the graphite film being the result of high-temperature graphitization of polyimide or by heat treatment of graphene oxide (or by hot pressing expandable graphite) [0011], both of which would form pyrolytic graphite. However, as currently claimed, Bai does not teach “the pyrolytic graphite comprises overlays of a plurality of graphene sheets, wherein portions of the graphene sheets extend transverse to the plane.”
Therefore, Yaun et al. (Polyimide-Derived Graphite Films with High Thermal Conductivity) teach and motivate the use of polyimide to form pyrolytic graphite films having a high thermal conductivity of 500-2,000 W/m·K (abstract), wherein using polyimide as the precursor to form highly oriented pyrolytic graphite is the preferred option, among forming highly oriented pyrolytic graphite via chemical vapor deposition, graphite formed from pressed worms (flakes) of graphite, and reductions of graphene oxide, wherein the industrialization of polyimide-derived graphite films offers a significant advantage in combination with its comparatively lower productions costs in comparison with other highly oriented graphite, its flexible nature, and high thermal conductivity of 700-1950 W/m·K such as with PGS from Panasonic, wherein graphitization becomes a significant factor at 2,000 °C, the ordered graphene layer structure appearing at around 2,400 °C, and a more ideal structure increasingly presents as the temperature increases up to 3,000 °C, wherein each of the films graphitized at 2,400 °C and 3,000 °C contain portions of the graphene sheets extending perpendicular to the plane (textured/corrugated surfaces and extensions/bumps, respectively) even when formed under pressure [Figs. 10-11], wherein the electrical resistivity of the 3,000 °C graphitized film nearly matches the theoretical value, wherein excellent thermal conductivity is attributed to the ordered three-dimensional structure of stacked (overlays of) graphene layers, wherein one of ordinary skill in the art comprising graphitizing polyimide films to obtain highly ordered pyrolytic graphite comprising a stack of graphene layers, wherein portions of the graphene layers extend transverse to the plane surface(s).
Furthermore, Bai teaches the holes in the graphite film are made via perforation with a needle (or an equivalent Z-pin), which should inherently form a portion of the graphene sheets adjacent the internal edge of the perforated holes, extending transverse to the plane of the pyrolytic graphite film due to its flexibility as demonstrated in Li et al. (Thermal conductivity enhancement and heat transport mechanism of carbon fiber z-pin graphite composite structures) [Figs. 6-7].
Applicant also mischaracterizes both disclosure and the Examiner’s reasoning regarding the carbon fibers. Applicant compared the carbon fiber of the reinforcement layers with the thermal conductivity of the heat conduction layers. However, these two aspects are completely different, wherein the heat conduction layer comprises the graphite film, which can be PGS from Panasonic, wherein the pitch fibers can further assist in the thermal conductivity of the composite. The “separate sheet of material” is already accounted for in both Bai and Mashiro, and Suzuki is a teaching reference regarding pitch carbon fibers in a carbon fiber reinforcement layer adjacent a heat conducting pyrolytic graphite film heat conduction layer in a heat conducting laminated composite. This is the exact same context that it is taught in Bai. Applicant’s misconstruing of this is confusing.
However, regarding the “porous layer” or any other aspects does not disclose all the features of the present claimed invention, Suzuki is used as teaching reference (teaching the concept of using pitch-based continuous carbon fibers rather than PAN-based, when choosing between the two most popularly used carbon fibers, wherein the choice of pitch would assist in thermal conduction adjacent a thermally conductive graphite layer), and therefore, it is not necessary for this secondary reference to contain all the features of the presently claimed invention, In re Nievelt, 482 F.2d 965, 179 USPQ 224, 226 (CCPA 1973), In re Keller 624 F.2d 413, 208 USPQ 871, 881 (CCPA 1981).
The Examiner is not disregarding the other teachings of Suzuki but rather understanding them in the context with which they are written. Applicant is simply picking apart the reference to misconstrue the teachings. The porous layer is not required to be structurally integrated into Bai.
Then Applicant tumbles into a rant about claim 14 when frankly claim 14 should be rejected over 112, 2nd paragraph and possibly 112, 1st paragraph. The specification teaches that “the composite should have a thermal conductivity than that of only carbon fibers”. Which direction is this referencing, the in-plane or out-of-plane direction? Does “than that of only carbon fibers” mean a composite only having carbon fibers or just the carbon fibers themselves? Is it the same carbon fibers as those used in the composite or any carbon fibers. It’s not a very good claim, to be honest.
Applicant assumes that any out-of-plane conductivity in Mashiro would result in the “burns” intended to be avoided thereby. However, the Examiner disagrees.
While Mashiro does emphasize in-plane thermal conductivity, it does not provide a limit or maximum value or a lack of through-thickness/out-of-plane conductivity such that burns will happen, but merely that some anisotropy is desired. Furthermore, Mashiro teaches that holes in the graphite film are present for strength and delamination prevention purposes [0027], but then demonstrates that the thermal conductivities of equivalent graphite composite films (examples 9 vs 12 & 16 vs 20) comprise lower in-plane thermal conductivities.
Duan teaches that not only does vertical conductivity increase due to the inclusion of the fillers extending and penetrating through the artificial graphite layers, but also mechanical strength and horizontal conductivity also increase thereby, even with an increase in thickness [n0040, 0043, n0065, n0085]. This may be explained by the fillers bridging the gaps created by the holes.
This is further corroborated by Chung (Processing-structure-property relationships of continuous carbon fiber polymer-matrix composites), which teaches that some important but mostly modest gains are made by incorporating carbon nanotubes into continuous carbon fiber composites, of either unidirectional carbon fiber laminates or woven carbon fiber laminates, for purposes of thermally conductivity, electrical conductivity (for EMI shielding purposes) usable in portable device electronics such as computers and cellular phones [pg. 11, 4.5.4.], and strength increasing purposes [pg. 13, 4.9], wherein the thermal conductivity can be enhanced in the through-thickness (out-of-plane) direction and at an even greater magnitude by in the in-plane direction by growing the carbon nanofibers on the continuous carbon fibers before incorporation into the resin matrix [pg. 16, 4.9.9.], wherein the thermal conductivity in both directions of the composite is largely governed by the fiber choice and in the thickness direction by the matrix material and to a lesser extent the fiber choice, wherein a pitch-based continuous carbon fiber epoxy matrix composite exhibits an in-plane thermal conductivity of 330 W/m·K and an out-of-plane thermal conductivity of 3-10 W/m·K and an intermediate modulus PAN-based continuous carbon fiber epoxy matrix composite exhibits an in-plane thermal conductivity of 6 W/m·K and an out-of-plane thermal conductivity of 0.5 W/m·K [pg. 10, 4.5.2.], and wherein the in-plane thermal conductivity can also be greatly increased by the incorporation of a highly oriented (pyrolytic) graphite film made by graphitizing a polymer film at a high temperature and having an in-plane direction thermal conductivity of 700 W/m·K and a through thickness direction conductivity thermal conductivity of 15 W/m·K, wherein the effect of incorporating a graphite film to a surface of a carbon fiber laminate is an increase of the in-plane thermal conductivity from 1 to 51 W/m·K or from 30 to 119 W/m·K for PAN-based fibers [pg. 22, 4.15.2.].
Also, Han et al. (Increasing the through-thickness thermal conductivity of carbon fiber polymer matrix composite by curing pressure increase and filler incorporation), teach that both in-plane heat spreading and through-thickness heat removal are important for heat dissipation especially as applied to heat sink in aircraft, wherein of the incorporation of carbon nanofibers and carbon nanotubes work more effectively than carbon black, especially at higher curing pressures which decrease interlaminar interface distance which can also be used with carbon woven fabric layered composites [Abstract, Introduction, Conclusion].
However, a new ground(s) of rejection has been made.
Applicant argues that Shar does not disclose thermal conductivity in relation to the carbon nanotubes. This is explicitly contradicted by the reference that, while electromagnetic shielding is emphasized, Shar teaches that thermal and/or electrical conductivity can be targeted by the addition of carbon nanotubes to the resin of the prepreg [0021-0022, 0061-0062]. Applicant is implored to fully read the references as they are being applied. Furthermore, the carbon nanotubes also increase shear strength
Applicant argues that Guo does not teach a CNT-infused carbon fiber/epoxy resin or a ratio of solar absorptivity to thermal emissivity, eliminating the need for a thermal coating/reflector. This feature is not claimed (at least in claim 1 or claims 17-18).
In response to Applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which Applicant relies (i.e. as recited above) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
The claim must be commensurate in scope with any proven and persuasive unexpected results. See MPEP 716.02(d). For instance, any of the PGS sheet (such as ones having a thickness of 25 µm or greater) in the prior art (and any composite comprising at least one PGS sheet) would inherently comprise a thermal emissivity and solar absorptivity within the claimed ranges according to Applicant’s results, and as such, the claimed invention is not commensurate in scope with any unexpected results.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
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.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 1-4, 6-7, 10-12, and 14-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claims 1 and 11, the only disclosure of “portions of the graphene sheets extend transverse to the plane” is available in the images, specifically Figs. 4c-4d, and is not described anywhere in the specification. However, it is unclear from the images how the plane is defined by the first substrate and therefore how the graphene sheet portions extend transversely thereto. Is the plane a central axis within the thickness or defined between the first and second sides. While the graphene sheets do seem to have a corrugated shape and/or portions deflecting in a non-linear manner, it appears that they extend within the thickness defined by the plane and therefore would be non-parallel to a plane defined by the first definition but would be parallel to a plane defined by the second definition, wherein it would be unclear to both definitions whether a plane is intersected or not (if it is required to be intersected).
Since images taken of the material in Applicant’s disclosure is a known product, PGS from Panasonic, it will be assumed for purposes of rejection that any prior art reference comprising the same product would inherently comprise the same features defined by the product and/or any prior art depictions of a product similar to the depictions set forth in the specification would impart the same features upon use or modification of a primary prior art reference.
Furthermore, it is unclear if the entire ranges of “at least 0.05 W/m·K” and “at least 20 W/m·K” are taught as both as disclosed as having endpoints [PGPub, 0106]. It is unclear if a composite having an in-plane conductivity of, for instance, 3,000 W/m·K would have been conceived at the time of invention.
Lastly, it is unclear if the plane of the composite (in-plane and out-of-plane conductivity) is related to the plane of the first substrate or is different but related thereto? They should be defined in relation to the composite as a whole.
Claim 12 is 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.
Regarding claim 12, it is unclear whether the comparison of the thermal conductivity is in the in-plane or out-of-plane direction.
Furthermore, it is unclear as claimed and as disclosed if the comparison is being made to a composite comprising only the carbon fibers or the carbon fibers themselves.
Claims 15-16 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.
AND
Claims 15-16 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Regarding claims 15-16, the composite of claim 1 now requires an in-plane thermal conductivity of “at least 20 W/m·K” and an out-of-plane thermal conductivity of “at least 0.5 W/m·K” but claims 15-16 are directed to ranges having lower boundaries of “about 20 W/m·K” and “about 0.5 W/m·K” which are broader ranges.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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, 6-11, 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Bai et al. (CN 108410136 A) (hereinafter “Bai”) in view of Yaun et al. (Polyimide-Derived Graphite Films with High Thermal Conductivity) (hereinafter “Yaun”) AND Suzuki et al. (WO 2021/106563 A1) (hereinafter “Suzuki”) using U.S. Pub. No. 2024/0149550 A1 as a translation/citation document AND/OR Deodati et al. (WO 2018/142298 A1) (hereinafter “Deodati”),
wherein claim 10 is further in view of Wable (Interfacial Toughening of Carbon Fiber Reinforced Polymer Matrix Composites using MWCNTs/Epoxy Nanofiber Scaffolds) OR Shar et al. (U.S. Pub. No. 2010/0270069 A1) (hereinafter “Shar”).
Regarding claims 1-4, 6-9, 11, 14-16, and 19-20, Bai teaches a graphite film/carbon fiber composite material plate [0008] that functions as a radiator in a satellite antenna or electronic system for spacecraft/aerospace which require extremely high heat transfer requirements [0004-0005], the graphite film/carbon fiber composite material plate comprising at least one perforated/mesh graphite films, having an in-plane thermal conductivity upon to about 1,800 W/m·K, such as those derived from the high temperature graphitization of polyimide, among choices such as heat treated graphene oxide and expandable graphene [0011, 0017, 0030] laminated with a carbon fiber prepreg [0019] and having nanofillers such as carbon nanotubes/carbon (nano)powder and boron nitride/carbon (nano)fibers [0020], wherein the nanofillers would combine with the resin of prepreg upon needling and hot pressing and curing [0020-0021], such that the nanofillers enter the holes/mesh structure of the graphite film, wherein the vertically oriented fillers in the holes improve interlaminar shear strength and out-of-plane thermal conductivity of the composite material [0020], wherein the graphite film has a thickness of 25 µm [0030] and the layers are alternatingly stacked such that there may be first and second graphite films or first and second outer carbon fiber prepregs [0019], wherein while the out-of-plane conductivity is not disclosed, the composite of Bai comprises identical/similar layer of graphite film(s), carbon fiber layers embedded in resin comprising nanofillers as claimed such that out-of-plane conductivity would have been inherently higher than at least 0.05 W/m·K, wherein products of identical structure and composition cannot have mutually exclusive properties. The burden is on the Applicants to prove otherwise. Furthermore, Bai desires at least some out-of-plane thermal conductivity greater than the value as set forth, as indicated by that an out-of-plane thermal conductivity of 0.6~1.2 W/m·K as being poor and due to the inclusion of nanofillers intended to enter the holes of the graphite film to increase out-of-plane thermal conductivity [0005]. Therefore, one of ordinary skill in the art would have expected Bai to inherently provide an out-of-plane thermal conductivity within the claimed range
However, the particulars or motivation to use the graphitized polyimide film such that the first substrate comprises overlays of graphene layers/sheets, portions of which extend transverse to the plane is not taught, and while only polyacrylonitrile-based fibers are taught as examples and the carbon fiber prepreg can be any commercially available product, but motivated use of pitch-based carbon fibers is not taught.
Yaun teaches high temperature graphitization of polyimide to form pyrolytic graphite films having a high thermal conductivity of 500-2,000 W/m·K (abstract), wherein using polyimide as the precursor to form highly oriented pyrolytic graphite is the preferred option, among forming highly oriented pyrolytic graphite via chemical vapor deposition, graphite formed from pressed worms (flakes) of graphite, and reductions of graphene oxide, wherein the industrialization of polyimide-derived graphite films offers a significant advantage in combination with its comparatively lower productions costs in comparison with other highly oriented graphite, its flexible nature, and high thermal conductivity of 700-1950 W/m·K such as with PGS from Panasonic, having bulk densities of 0.85 to 2.13 g/cm3, sheet thicknesses of 0.10-0.01 mm (10-100 µm), and in-plane thermal conductivities of 700-1950 W/m·K, wherein the thickness is inversely related to the thermal conductivity with films of 20-50 W/m·K, wherein graphitization becomes a significant factor at 2,000 °C, the ordered graphene layer structure appearing at around 2,400 °C, and a more ideal layered graphene structure increasingly presents as the temperature increases up to 3,000 °C, wherein each of the films graphitized at 2,400 °C and 3,000 °C contain portions of the graphene sheets extending perpendicular to the plane (textured/corrugated surfaces and extensions/bumps, respectively) even when formed under pressure [Figs. 10-11], wherein the electrical resistivity of the 3,000 °C graphitized film nearly matches the theoretical value and having a bulk density of about 2.0 g/cm3 and an average thickness of 20-50 µm, wherein excellent thermal conductivity is attributed to the ordered three-dimensional structure of stacked (overlays of) graphene layers.
It would have been obvious to one of ordinary skill in the art at the time of invention to provide graphitized polyimide at temperatures above 2400 °C, and up to and above 3000 °C, as the graphitized film such that the graphite film comprises overlays of graphene layers/sheets, portions of which extend transverse to the plane. One of ordinary skill in the art would have been motivated to use a repeatedly flexible, higher in strength/toughness and thermally conductivity (relative to expanded/”flexible” graphite), and reproducible efficiently and economically at an industrial-scale (relative to reduced graphene and CVD graphene) as the graphite film [Yaun].
Suzuki teaches a sandwich structure, usable in applications such as electric/electronic equipment, robots, and/or air- or land- vehicles that achieves high heat dissipation/radiation (radiator) and excellent mechanical characteristics [0002, 0105], the sandwich structure comprising at least one thermally conductive member (III) and at least one fiber-reinforced member (II), such as a thermally conductive member located between two fiber reinforced members [Fig. 4], being bonded by heat-pressing such that delamination does not occur [0064-0066, 0075, 0099-0100], wherein the thermally conductive member is a graphite sheet obtained from graphitizing/pyrolyzing a polymer film [0039-0041, 0099] having an in-plane thermal conductivity of more preferably 1,000 W/m·K or more [0036] and an average thickness of more preferably 15 µm and 0.5 mm (500 µm) or less [0042], wherein the fiber reinforced member comprises a thermoplastic or thermosetting resin impregnated carbon fiber, in the form of short or long, such as continuous unidirectional or woven fibers, wherein pitch-based carbon fiber members are preferable due to increased rigidity/modulus and heat dissipation [0058-0061].
AND/OR
Deodati teaches a heat dissipating composite made from prepreg layers of unidirectional or woven carbon fibers embedded in a polymer matrix usable for sources with a high heat dissipation requirements, improved over the use of metals such as aluminum or copper, wherein the carbon fibers are preferably of the pitch-type due to their higher elastic modulus and much higher thermal conductivity, being above 100 W/m·K, up to 1000 W/m·K (pg. 10, line 28 – pg. 11, line 33; pg. 13, lines 25-31; pg. 20, lines 12-22; & claim 2) and preferably also comprise thermally conductive filler, such as metal particles, ceramic particles, or carbonaceous particles, in order to improve out-of-plane thermal conductivity which is poor with carbon fiber based laminates due to the low transverse thermal conductivity of both PAN- and pitch-based carbon fibers in relation to the in-plane thermal conductivity (both on the order of ~10 W/m·K) and the even lower polymeric matrix thermal conductivity, often less than 1 W/m·K (pg. 12, lines 1-19; pg. 20, lines 12-22; & claim 3).
It would have been obvious to one of ordinary skill in the art at the time of invention to provide pitch-based carbon fibers to a thermally conductive composite comprising carbon fiber prepreg layers and graphite films and/or nanofillers in the impregnating resin. One of ordinary skill in the art would have been motivated to utilize a carbon fiber type that has an increased rigidity/modulus and heat dissipation [Suzuki] AND/OR has an increased elastic modulus and thermal conductivity [Deodati].
Regarding claim 10, Wable teaches the incorporation of carbon nanotubes into the prepreg epoxy resin of continuous carbon fiber reinforced composites, due to the poor thermal conductivity of epoxy resin of 0.1 to 0.2 W/m·K, wherein amongst many nanofillers carbon nanotubes are considered one of the best, wherein the carbon nanotubes doped in small amounts, such as about 2 wt%, 4 wt%, or 8 wt%, generates a vast conductive network within the resin that not only builds a strong build between layers but also transmits heat flow effortlessly between CFRP layers, wherein similar amounts also work for electrical conductivity and EMI shielding (pgs. 73-75).
OR
Shar teaches a CNT-infused carbon fiber resin composite, which grants the extremely high thermal and electrical conduction of the CNTs to both the composite fiber and the overall composite, being especially useful in electromagnetic interference shielding, but also able to target desired thermal conductivities as a function of the CNT weight percentage added, such as <1 wt% to >2 wt% for EMI shielding or more generally, being between about 1 wt% to about 7 wt%, but further can be up to (and optionally over) 20 wt% [0021-0022, 0025, 0028, 0043, 0061-0062, 0078].
It would have been obvious to and motivated for one of ordinary skill in the art at the time of invention to look to the art for possible CNT wt% amounts for resin inclusion for the desired effects of shear strengthening and/or thermal conductivity and/or electrical conductivity.
Regarding claims 6-7, while a particular thermal diffusivity for the pyrolytic graphite sheet and a tensile strength for or density for the carbon fibers is not taught, without additional structural limitations, the pyrolytic graphite sheet of Bai/Yaun and the pitch carbon fibers of Bai/Suzuki and/or Bai/Deodati are considered inherent to the structure(s) that has/have the same or similar composition and structure to the claimed elements.
Regarding claims 17-18, while a particular thermal emissivity or solar absorptivity have not been taught, both are considered inherent to the composite structure that has the same or similar composition and structure to the claimed elements.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Bai in view of Yaun and Deodati and/or Suzuki, as applied to claim 11 above, further in view of Ma et al. (CN 111923425 A) (hereinafter “Ma”).
Regarding claim 12, the pyrolytic graphite sheet is not said to be treated as claimed before coupling.
Ma teaches a high thermal conductivity graphite film-carbon fiber resin-based composite material, wherein the graphite film is a sintered polymer film and comprises a thickness of 25 to 100 µm, a density of 1.0 to 1.9 g/cc, and an in-plane thermal conductivity of 2000 W/m·K and a cross-plane conductivity of 15 W/m·K, wherein carbon fiber reinforced resin composites comprise a low density and high strength/modulus [0002-0005], wherein before the two differing materials are bonded the graphite film is subjected to plasma treatment which along with alkaline/acid washing provides a good interface for bonding [0025, 0031-0032, 0042].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a plasma treatment to the graphite film before coupling. One of ordinary skill in the art would have been motivated to provide a good interface for bonding [0025, 0031-0032, 0042].
Claims 17-18 are alternatively rejected under 35 U.S.C. 103 as being unpatentable over Bai in view of Yaun and Deodati and/or Suzuki, as applied to claim 1 above, further in view of Guo et al. (Thermal management with a highly emissive and thermally conductive graphite absorber) (hereinafter “Guo”).
Regarding claims 17-18, in the event that thermal emissivity and solar absorptivity of the composite are not inherent/obvious as recited above:
Guo teaches a thermal management for industrial, solar, and electronic uses, wherein a pyrolytic graphite that is graphitized from a polyimide film and surface treated by etching can provide a hemispherical reflectance is around 1% in the visible range (450 nm to 850 nm) and less than 1% from 1.5 to 10 µm, such that absorbance/emissivity could be tuned in the visible and near to far-infrared regions, which would increase cooling and heat dissipation by several degrees even over CVD graphite or metal coated graphite [Abstract, Introduction, Conclusion].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the composite with a thermal emissivity and solar absorptivity as claimed. One of ordinary skill in the art would have been motivated to substantially improve cooling and heat dissipation in a pyrolytic graphite film [Abstract, Introduction, Conclusion].
Claims 1-4, 6-11, & 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Mishiro et al. (JP 2010-064391 A) (hereinafter “Mishiro”), as evidenced by Farnell (Solving thermal management challenges in a minimum space) (hereinafter “Farnell”) and Wable (Interfacial Toughening of Carbon Fiber Reinforced Polymer Matrix Composites using MWCNTs/Epoxy Nanofiber Scaffolds), in view of Ikeda et al. (JP 2012-109452 A) (hereinafter “Ikeda”), Wei et al. (CN 112280077 A) (hereinafter “Wei”), and Shar et al. (U.S. Pub. No. 2010/0270069 A1) (hereinafter “Shar”).
Regarding claims 1-4, 6-11, 14-15, and 19-20, Mashiro teaches a graphite composite film light in weight, excellent in mechanical strength, and even more excellent in thermal conductivity to be used as a heat spreader material (radiator) such as in an electronic material or an aircraft member [0001, 0007, 0040], the graphite composite film comprising at least one graphite film bonded to at least one resin pre-impregnated reinforcing fiber layer by heat pressing [0036], wherein relatively lower conductivity of the reinforcing fiber layer is compensated for the by graphite film and the relatively lower strength of the graphite film is compensated for by the reinforcing fiber layer [0003, 0005], wherein the reinforcing fiber is preferably a carbon fiber and the resin is thermoplastic and/or thermosetting, such as an aligned unidirectional carbon fiber [0021-0023] and the graphite film is preferably formed by pyrolysis/ graphitization of a polymer film at temperatures above 2800 °C, preferably polyimide due to the resulting graphite having excellent crystallinity, the graphite film having a thermal conductivity of 200 W/m·K or more, more preferably 1000 W/m·K or more, a density of 1.0 g/cc or more, more preferably 1.8 g/cc or more, a thickness of 3 µm or more and 500 µm or less [0002, 0024-0025, 0029-0032], wherein Farnell evidences pyrolytic graphene sheets having a high in-plane thermal conductivity that is two to five times higher than copper and up to seven times better than aluminum, wherein PGS can provide at thicknesses of 10 µm to 100 µm in-plane thermal conductivities of 700 W/m·K to 1950 W/m·K, such as about 1600 W/m·K for a 25 µm, is flexible and able to undergo repeated bending, comprising a plurality of graphene layers/sheets having portions extending transverse to the plane defined by the graphite film, and some electromagnetic shielding providing a simultaneous EMI and thermal solution of attenuation of 90-100 dB at frequencies of about 10 MHz to around 5,000 MHz [Farnell], wherein Mashiro further teaches that the graphite films are perforated with a plurality of through holes prior to bonding, which allows the layers to become more thoroughly combined [0027, 0048], wherein composite graphite film has a thermal conductivity of at least 10 W/m·K, preferably 50 W/m·K and a tensile strength of 300 MPa or more and preferably 500 MPa or more [0040-0041], wherein in multiple examples graphite films A, B, or E (perforated A) were formed by pyrolyzing a polyimide film to 2900 °C or higher, wherein graphite films A and E comprise a thickness of 25 µm, a density of 1.86 g/cm3, a thermal diffusivity of 9.1 cm2/s, and a thermal conductivity of 1,200 W/m·K and graphite film B comprises a thickness of 40 µm, a density of 1.86 g/cm3, a thermal diffusivity of 9.5 cm2/s, and a thermal conductivity of 1,200 W/m·K [0043-0045, 0048] and the resin-impregnated carbon fiber reinforcing layers [0053-0056] are bonded by heat-pressing [0059-0062] as a two-layer structure [0059-0062, 0079-0080], as a three-layer structure including a second carbon fiber reinforcing layer on the other side of the graphite film [0067-0068, 0070], or as a three-layer structure including a graphite film on the other side of the carbon fiber reinforcing layer [0074-0075, 0078], wherein the examples cited as meeting the claimed limitations (1-4, 9-10, 12, 16-17, 20-22) comprising an in-plane thermal conductivity ranging from 87 to 740 W/m·K, wherein examples 3, 16-17, 20, and 22 have both excellent mechanical and thermal properties, wherein the comparative example comprising only laminated layers of carbon reinforcing fiber layer A only comprises an in-plane thermal conductivity of 5 W/m·K and a tensile strength of greater than 500 MPa [0084, 0088-0089], wherein the lowest thermal conductivity component in the thickness direction would be that of epoxy resin being about 0.1 to 0.2 W/m·K as evidenced by Wable, meaning that the composite comprising each claimed element should have an out-of-plane thermal conductivity inherently within the claimed range.
However, the resin comprising nanomaterials, specifically carbon nanotubes (in the weight percent claimed), and the carbon fibers being pitch-based are not taught.
Ikeda teaches composite materials for electromagnetic shielding for electronics housing such as a mobile phone [0084] comprising a fiber reinforced resin molded portion, wherein high heat dissipation along with electromagnetic shielding is desired, preferably pitch-based carbon fibers in comparison to PAN-based carbon fibers are used, pitch-based carbon fibers having a tensile modulus greater than 400 GPa, most preferably 500 to 900 GPa, and an axial thermal conductivity of greater than 60 W/m·K, preferably 120 to 600 W/m·K [0026, 0037, 0043] and a metal layer, preferably aluminum, also for further shielding electromagnetic waves [0028, 0083].
AND
Wei teaches a composite with electromagnetic shielding comprising embedded electromagnetic wave absorbing materials into the composite, wherein the shielding prepreg comprises carbon fiber layers embedded in resin laminated to at least one shielding layer, wherein resin further comprises a nanofiller, preferably one of carbon nanotubes, graphene nanoplatelets, or at about 1 to 10 wt% [0011-0014, 0016-0019], and the shielding layer is a metal mesh, carbon nanofilm, or a graphene film with ductility [0020] providing the prepreg with a shielding effectiveness of greater than 40 dB [0029].
AND
Shar teaches a CNT-infused carbon fiber resin composite, which grants the extremely high thermal and electrical conduction of the CNTs to both the composite fiber and the overall composite, being especially useful in electromagnetic interference shielding housing structures for a shielding effectiveness in a frequency range of about 0.01 MHz to about 18 GHz of about 40 to 130 dB, such as <1 wt% to >2 wt% for EMI shielding or more generally, being between about 1 wt% to about 7 wt%, but further can be up to (and optionally over) 20 wt% [0021-0022, 0025, 0028, 0043, 0061-0062, 0078].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the composite for electronics housing with an electromagnetic shielding capability along with high thermal dissipation via the inclusion of pitch-based carbon fibers and graphite film as claimed. One of ordinary skill in the art would have been motivated to provide an electronic housing with the already available components with each component having increased electromagnetic shielding capabilities, the carbon fibers further modified to comprise pitch-based carbon fibers having increased combined electromagnetic shielding and heat dissipating abilities [Ikeda] and the resin including nanotubes in addition to the carbon fiber layers and graphene film layer(s) for excellent EMI shielding [Wei/Shar].
Regarding claims 7, tensile strength for or density for the carbon fibers is not taught, without additional structural limitations, the pitch carbon fibers of Mashiro/Ikeda are considered inherent to the structure(s) that has/have the same or similar composition and structure to the claimed elements.
Regarding claims 17-18, while a particular thermal emissivity or solar absorptivity have not been taught, both are considered inherent to the composite structure that has the same or similar composition and structure to the claimed elements.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Mashiro in view of Ikeda, Wei, and Shar, as applied to claim 11 above, further in view of Ma et al. (CN 111923425 A) (hereinafter “Ma”).
Regarding claim 12, the pyrolytic graphite sheet is not said to be treated as claimed before coupling.
Ma teaches a high thermal conductivity graphite film-carbon fiber resin-based composite material, wherein the graphite film is a sintered polymer film and comprises a thickness of 25 to 100 µm, a density of 1.0 to 1.9 g/cc, and an in-plane thermal conductivity of 2000 W/m·K and a cross-plane conductivity of 15 W/m·K, wherein carbon fiber reinforced resin composites comprise a low density and high strength/modulus [0002-0005], wherein before the two differing materials are bonded the graphite film is subjected to plasma treatment which along with alkaline/acid washing provides a good interface for bonding [0025, 0031-0032, 0042].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a plasma treatment to the graphite film before coupling. One of ordinary skill in the art would have been motivated to provide a good interface for bonding [0025, 0031-0032, 0042].
Claims 17-18 are alternatively rejected under 35 U.S.C. 103 as being unpatentable over Mashiro in view of Ikeda, Wei, and Shar, as applied to claim 1 above, further in view of Guo et al. (Thermal management with a highly emissive and thermally conductive graphite absorber) (hereinafter “Guo”).
Regarding claims 17-18, in the event that thermal emissivity and solar absorptivity of the composite are not inherent/obvious as recited above:
Guo teaches a thermal management for industrial, solar, and electronic uses, wherein a pyrolytic graphite that is graphitized from a polyimide film and surface treated by etching can provide a hemispherical reflectance is around 1% in the visible range (450 nm to 850 nm) and less than 1% from 1.5 to 10 µm, such that absorbance/emissivity could be tuned in the visible and near to far-infrared regions, which would increase cooling and heat dissipation by several degrees even over CVD graphite or metal coated graphite [Abstract, Introduction, Conclusion].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the composite with a thermal emissivity and solar absorptivity as claimed. One of ordinary skill in the art would have been motivated to substantially improve cooling and heat dissipation in a pyrolytic graphite film [Abstract, Introduction, Conclusion].
Claims 1-2, 4, 6-11, & 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Hayashi et al. (U.S. Pub. No. 2010/0327737 A1) (hereinafter “Hayashi”) in view of Yaun et al. (Polyimide-Derived Graphite Films with High Thermal Conductivity) (hereinafter “Yaun”), Deodati et al. (WO 2018/142298 A1) (hereinafter “Deodati”), and Wable (Interfacial Toughening of Carbon Fiber Reinforced Polymer Matrix Composites using MWCNTs/Epoxy Nanofiber Scaffolds).
Regarding claims 1-2, 4, 6-11, 14-15, and 19-20, Hayashi teaches a light emitting device comprising a heat dissipating reinforcing member (radiator) comprising a laminate of directional carbon fiber plies embedded in resin, such as epoxy, the carbon fiber being either PAN-based or pitch-based [0018-0020, 0022, 0050-0052, 0153-0163], wherein a graphite layer is disposed adjacent and/or between one or more of the carbon layers, the graphite layer comprising a plurality of holes allowing bonding of flanking carbon fiber layers therethrough [0394-0401], wherein the graphite layer comprises graphitizing a polyimide film at 1000 °C or by rolling graphite particles into a film, the graphite having a hexagonal structure [0328].
However, it is not clear if the graphite layer is a pyrolytic graphite sheet as claimed or that the resin impregnating the carbon fibers further comprises a nanofiber as claimed.
Yaun teaches high temperature graphitization of polyimide to form pyrolytic graphite films having a high thermal conductivity of 500-2,000 W/m·K (abstract), wherein using polyimide as the precursor to form highly oriented pyrolytic graphite is the preferred option, among forming highly oriented pyrolytic graphite via chemical vapor deposition, graphite formed from pressed worms (flakes) of graphite, and reductions of graphene oxide, wherein the industrialization of polyimide-derived graphite films offers a significant advantage in combination with its comparatively lower productions costs in comparison with other highly oriented graphite, its flexible nature, and high thermal conductivity of 700-1950 W/m·K such as with PGS from Panasonic, having bulk densities of 0.85 to 2.13 g/cm3, sheet thicknesses of 0.10-0.01 mm (10-100 µm), and in-plane thermal conductivities of 700-1950 W/m·K, wherein the thickness is inversely related to the thermal conductivity with films of 20-50 W/m·K, wherein graphitization becomes a significant factor at 2,000 °C, the ordered graphene layer structure appearing at around 2,400 °C, and a more ideal layered graphene structure increasingly presents as the temperature increases up to 3,000 °C, wherein each of the films graphitized at 2,400 °C and 3,000 °C contain portions of the graphene sheets extending perpendicular to the plane (textured/corrugated surfaces and extensions/bumps, respectively) even when formed under pressure [Figs. 10-11], wherein the electrical resistivity of the 3,000 °C graphitized film nearly matches the theoretical value and having a bulk density of about 2.0 g/cm3 and an average thickness of 20-50 µm, wherein excellent thermal conductivity is attributed to the ordered three-dimensional structure of stacked (overlays of) graphene layers.
It would have been obvious to one of ordinary skill in the art at the time of invention to provide graphitized polyimide at temperatures above 2400 °C, and up to and above 3000 °C, as the graphitized film such that the graphite film comprises overlays of graphene layers/sheets, portions of which extend transverse to the plane. One of ordinary skill in the art would have been motivated to use a repeatedly flexible, higher in strength/toughness and thermally conductivity (relative to expanded/”flexible” graphite), and reproducible efficiently and economically at an industrial-scale (relative to reduced graphene and CVD graphene) as the graphite film [Yaun].
Deodati teaches a heat dissipating composite made from prepreg layers of unidirectional or woven carbon fibers embedded in a polymer matrix usable for sources with a high heat dissipation requirements, improved over the use of metals such as aluminum or copper, wherein the carbon fibers are preferably of the pitch-type due to their higher elastic modulus and much higher thermal conductivity, being above 100 W/m·K, up to 1000 W/m·K (pg. 10, line 28 – pg. 11, line 33; pg. 13, lines 25-31; pg. 20, lines 12-22; & claim 2) and preferably also comprise thermally conductive filler, such as metal particles, ceramic particles, or carbonaceous particles, in order to improve out-of-plane thermal conductivity which is poor with carbon fiber based laminates due to the low transverse thermal conductivity of both PAN- and pitch-based carbon fibers in relation to the in-plane thermal conductivity (both on the order of ~10 W/m·K) and the even lower polymeric matrix thermal conductivity, often less than 1 W/m·K (pg. 12, lines 1-19; pg. 20, lines 12-22; & claim 3).
It would have been obvious to one of ordinary skill in the art at the time of invention to provide both pitch-based carbon fibers and nanofillers in the impregnating resin. One of ordinary skill in the art would have been motivated to utilize an increased elastic modulus and thermal conductivity [Deodati].
Wable teaches the incorporation of carbon nanotubes into the prepreg epoxy resin of continuous carbon fiber reinforced composites, due to the poor thermal conductivity of epoxy resin of 0.1 to 0.2 W/m·K, wherein amongst many nanofillers carbon nanotubes are considered one of the best, wherein the carbon nanotubes doped in small amounts, such as about 2 wt%, 4 wt%, or 8 wt%, generates a vast conductive network within the resin that not only builds a strong build between layers but also transmits heat flow effortlessly between CFRP layers, wherein similar amounts also work for electrical conductivity and EMI shielding (pgs. 73-75).
It would have been obvious to one of ordinary skill in the art at the time of invention to provide pitch-based carbon fibers to a thermally conductive composite comprising carbon fiber prepreg layers and graphite films and/or nanofillers, specifically the best comprising carbon nanotubes, in the impregnating resin. One of ordinary skill in the art would have been motivated to further increase out-of-plane thermal conductivity [Deodati], wherein one of ordinary skill in the art would have looked to the art for possible CNT wt% amounts for resin inclusion for the desired effects of shear strengthening and/or thermal conductivity and/or electrical conductivity [Wable].
Regarding claims 6-7, while a particular thermal diffusivity for the pyrolytic graphite sheet and a tensile strength for or density for the carbon fibers is not taught, without additional structural limitations, the pyrolytic graphite sheet of Hayashi/Yaun and the pitch carbon fibers of Hayashi/Deodati/Wable are considered inherent to the structure(s) that has/have the same or similar composition and structure to the claimed elements.
Regarding claims 17-18, while a particular thermal emissivity or solar absorptivity have not been taught, both are considered inherent to the composite structure that has the same or similar composition and structure to the claimed elements.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Hayashi in view of Yuan, Deodati, and Wable, as applied to claim 11 above, further in view of Ma et al. (CN 111923425 A) (hereinafter “Ma”).
Regarding claim 12, the pyrolytic graphite sheet is not said to be treated as claimed before coupling.
Ma teaches a high thermal conductivity graphite film-carbon fiber resin-based composite material, wherein the graphite film is a sintered polymer film and comprises a thickness of 25 to 100 µm, a density of 1.0 to 1.9 g/cc, and an in-plane thermal conductivity of 2000 W/m·K and a cross-plane conductivity of 15 W/m·K, wherein carbon fiber reinforced resin composites comprise a low density and high strength/modulus [0002-0005], wherein before the two differing materials are bonded the graphite film is subjected to plasma treatment which along with alkaline/acid washing provides a good interface for bonding [0025, 0031-0032, 0042].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a plasma treatment to the graphite film before coupling. One of ordinary skill in the art would have been motivated to provide a good interface for bonding [0025, 0031-0032, 0042].
Claims 17-18 are alternatively rejected under 35 U.S.C. 103 as being unpatentable over Hayashi in view of Yuan, Deodati, and Wable, as applied to claim 1 above, further in view of Guo et al. (Thermal management with a highly emissive and thermally conductive graphite absorber) (hereinafter “Guo”).
Regarding claims 17-18, in the event that thermal emissivity and solar absorptivity of the composite are not inherent/obvious as recited above:
Guo teaches a thermal management for industrial, solar, and electronic uses, wherein a pyrolytic graphite that is graphitized from a polyimide film and surface treated by etching can provide a hemispherical reflectance is around 1% in the visible range (450 nm to 850 nm) and less than 1% from 1.5 to 10 µm, such that absorbance/emissivity could be tuned in the visible and near to far-infrared regions, which would increase cooling and heat dissipation by several degrees even over CVD graphite or metal coated graphite [Abstract, Introduction, Conclusion].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the composite with a thermal emissivity and solar absorptivity as claimed. One of ordinary skill in the art would have been motivated to substantially improve cooling and heat dissipation in a pyrolytic graphite film [Abstract, Introduction, Conclusion].
Claims 1-4, 6-9, 11, & 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Mishiro et al. (JP 2010-064391 A) (hereinafter “Mishiro”), as evidenced by Yaun et al. (Polyimide-Derived Graphite Films with High Thermal Conductivity) (hereinafter “Yaun”), in view of Duan et al. (CN 113276487 A) (hereinafter “Duan”), Chung (Processing-structure-property relationships of continuous carbon fiber polymer-matrix composites), and optionally also in view of Deodati et al. (WO 2018/142298 A1) (hereinafter “Deodati”), and Wable (Interfacial Toughening of Carbon Fiber Reinforced Polymer Matrix Composites using MWCNTs/Epoxy Nanofiber Scaffolds).
Regarding claims 1-7, 9, 11, 14-15, and 19-20, Mashiro teaches a graphite composite film light in weight, excellent in mechanical strength, and even more excellent in thermal conductivity to be used as a heat spreader material (radiator) in an aircraft member [0001, 0007, 0040], the graphite composite film comprising at least one graphite film bonded to at least one resin pre-impregnated reinforcing fiber layer by heat pressing [0036], wherein relatively lower conductivity of the reinforcing fiber layer is compensated for the by graphite film and the relatively lower strength of the graphite film is compensated for by the reinforcing fiber layer [0003, 0005], wherein the reinforcing fiber is preferably a carbon fiber and the resin is thermoplastic and/or thermosetting, such as an aligned unidirectional carbon fiber [0021-0023] and the graphite film is preferably formed by pyrolysis/graphitization of a polymer film at temperatures above 2800 °C, preferably polyimide due to the resulting graphite having excellent crystallinity, the graphite film having a thermal conductivity of 200 W/m·K or more, more preferably 1000 W/m·K or more, a density of 1.0 g/cc or more, more preferably 1.8 g/cc or more, a thickness of 3 µm or more and 500 µm or less [0002, 0024-0025, 0029-0032], wherein Yaun teaches high temperature graphitization of polyimide to form pyrolytic graphite films having a high thermal conductivity of 500-2,000 W/m·K (abstract) and an out-of-plane thermal conductivity much less, such as about 5.7 W/m·K in comparison to the in-plane thermal conductivity of 2,000 W/m·K, wherein graphitization becomes a significant factor at 2,000 °C, the ordered graphene layer structure appearing at around 2,400 °C, and a more ideal layered graphene structure increasingly presents as the temperature increases up to 3,000 °C, wherein each of the films graphitized at 2,400 °C and 3,000 °C contain portions of the graphene sheets extending perpendicular to the plane (textured/corrugated surfaces and extensions/bumps, respectively) even when formed under pressure [Figs. 10-11], wherein excellent thermal conductivity is attributed to the ordered three-dimensional structure of stacked (overlays of) graphene layers [Yaun], wherein Mashiro further teaches that the graphite films are perforated with a plurality of through holes prior to bonding, which allows the layers to become more thoroughly combined [0027, 0048], wherein composite graphite film has a thermal conductivity of at least 10 W/m·K, preferably 50 W/m·K and a tensile strength of 300 MPa or more and preferably 500 MPa or more [0040-0041], wherein in multiple examples graphite films A, B, or E (perforated A) were formed by pyrolyzing a polyimide film to 2900 °C or higher, wherein graphite films A and E comprise a thickness of 25 µm, a density of 1.86 g/cm3, a thermal diffusivity of 9.1 cm2/s, and a thermal conductivity of 1,200 W/m·K and graphite film B comprises a thickness of 40 µm, a density of 1.86 g/cm3, a thermal diffusivity of 9.5 cm2/s, and a thermal conductivity of 1,200 W/m·K [0043-0045, 0048] and the resin-impregnated carbon fiber reinforcing layers [0053-0056] are bonded by heat-pressing [0059-0062] as a two-layer structure [0059-0062, 0079-0080], as a three-layer structure including a second carbon fiber reinforcing layer on the other side of the graphite film [0067-0068, 0070], or as a three-layer structure including a graphite film on the other side of the carbon fiber reinforcing layer [0074-0075, 0078].
However, the resin comprising nanomaterials, specifically carbon nanotubes (in the weight percent claimed), and the carbon fibers being pitch-based are not taught.
Duan teaches a high thermal conductivity composite film for heat dissipation comprising a polyimide-based graphite composite film, wherein some higher demand military and aerospace industries which require anisotropic thermal conductivity that is high in both the horizontal and vertical directions [n0007, n0040], wherein in-plane reinforcement layers of carbon fibers and/or graphite films formed from a graphitized PI film having a horizontal thermal conductivity greater than 1000 W/m·K, preferably 1500 W/m·K [n0061-n0062], wherein the in-plane reinforcement layer preferably comprises a plurality of holes which allow for the penetration of resin and fillers to provide a higher vertical thermal conductivity [n0063, n0065] are adhered to each other via a resin binder premix layers comprising a plurality of thermally conductive carbon-based auxiliary agents, such as carbon nanotubes, and thermally conductive fillers [n0008-0010, n0013, n0021-0022, n0045, n0056, n0085], such that a total composite film thickness of 0.5 -1.0 mm (500-1000 µm) comprises a horizontal/in-plane thermal conductivity is 300 to 1000 W/m·K and a vertical/through-plane thermal conductivity is 10 to 50 W/m·K, preferably an in-plane conductivity 550-1000 W/m·K and an out-of-plane thermal conductivity of 20-50 W/m·K, providing an anisotropic thermally conducting composite material [n0019, n0043, n0067-n0068], such as providing 10 layers of 25 µm thick perforated graphite film having a thermal conductivity of 1500 W/m·K for an overall thickness of 0.55 (550 µm) an in-plane thermal conductivity of 650 W/m·K and an out-of-plane thermal conductivity of 20 W/m·K [n0103-n0105] or 30-40 layers of 10 µm thick perforated graphite film having a thermal conductivity of 2000 W/m·K for an overall thickness of 1 mm (1000 µm) an in-plane thermal conductivity of 700 W/m·K and an out-of-plane thermal conductivity of 20 W/m·K [n0110-n0112].
AND
Chung teaches the thermal conductivity in both directions of a fiber-reinforced composite is largely governed by the fiber choice and in the thickness direction by the matrix material and to a lesser extent the fiber choice, wherein a pitch-based continuous carbon fiber epoxy matrix composite exhibits an in-plane thermal conductivity of 330 W/m·K and an out-of-plane thermal conductivity of 3-10 W/m·K and an intermediate modulus PAN-based continuous carbon fiber epoxy matrix composite exhibits an in-plane thermal conductivity of 6 W/m·K and an out-of-plane thermal conductivity of 0.5 W/m·K [pg. 10, 4.5.2.].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide one or more prepregs comprising continuous pitch-based carbon fibers and a thermally conductive filler including carbon nanotubes within the resin filling the holes of the graphite layer. One of ordinary skill in the art would have been motivated to adapt the aircraft member for military or aerospace purposes [Duan] having a thermally conductive filler fill the holes to increase strength and vertical conductivity as desired [Duan], wherein the pitch-based carbon fiber would have been substituted for the PAN-based one in order to maintain a higher carbon fiber in-plane conductivity for a non-graphite film-based layer and further increase out-of-plane thermal conductivity [Chung].
Further regarding claim 11 and regarding claim 10, in the event that a carbon nanotube is not taught to be included in the prepreg resin (within the amount claimed).
Deodati teaches a heat dissipating composite made from prepreg layers of unidirectional or woven carbon fibers embedded in a polymer matrix usable for sources with a high heat dissipation requirements, improved over the use of metals such as aluminum or copper, wherein the carbon fibers are preferably of the pitch-type due to their higher elastic modulus and much higher thermal conductivity, being above 100 W/m·K, up to 1000 W/m·K (pg. 10, line 28 – pg. 11, line 33; pg. 13, lines 25-31; pg. 20, lines 12-22; & claim 2) and preferably also comprise thermally conductive filler, such as metal particles, ceramic particles, or carbonaceous particles, in order to improve out-of-plane thermal conductivity which is poor with carbon fiber based laminates due to the low transverse thermal conductivity of both PAN- and pitch-based carbon fibers in relation to the in-plane thermal conductivity (both on the order of ~10 W/m·K) and the even lower polymeric matrix thermal conductivity, often less than 1 W/m·K (pg. 12, lines 1-19; pg. 20, lines 12-22; & claim 3).
Wable teaches the incorporation of carbon nanotubes into the prepreg epoxy resin of continuous carbon fiber reinforced composites, due to the poor thermal conductivity of epoxy resin of 0.1 to 0.2 W/m·K, wherein amongst many nanofillers, including ceramic nanoparticles, carbon nanotubes are considered the best, wherein the carbon nanotubes doped in small amounts, such as about 2 wt%, 4 wt%, or 8 wt%, generates a vast conductive network within the resin that not only builds a strong build between layers but also transmits heat flow effortlessly between CFRP layers, wherein similar amounts also work for electrical conductivity and EMI shielding (pgs. 73-75).
It would have been obvious to one of ordinary skill in the art at the time of invention to provide pitch-based carbon fibers to a thermally conductive composite comprising carbon fiber prepreg layers and graphite films and/or nanofillers in the impregnating resin. One of ordinary skill in the art would have been motivated to further increase out-of-plane thermal conductivity [Deodati] in order to reach the preferred range of Duan, wherein one of ordinary skill in the art would have looked to the art for possible CNT wt% amounts for resin inclusion for the desired effects of shear strengthening and/or thermal conductivity and/or electrical conductivity [Wable].
Regarding claims 7, tensile strength for or density for the carbon fibers is not taught, without additional structural limitations, the pitch carbon fibers of Mashiro/Deodati are considered inherent to the structure(s) that has/have the same or similar composition and structure to the claimed elements.
Regarding claims 17-18, while a particular thermal emissivity or solar absorptivity have not been taught, both are considered inherent to the composite structure that has the same or similar composition and structure to the claimed elements.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Mishiro in view of Duan, Chung, and optionally Deodati and Wable, as applied to claim 11 above, further in view of Ma et al. (CN 111923425 A) (hereinafter “Ma”).
Regarding claim 12, the pyrolytic graphite sheet is not said to be treated as claimed before coupling.
Ma teaches a high thermal conductivity graphite film-carbon fiber resin-based composite material, wherein the graphite film is a sintered polymer film and comprises a thickness of 25 to 100 µm, a density of 1.0 to 1.9 g/cc, and an in-plane thermal conductivity of 2000 W/m·K and a cross-plane conductivity of 15 W/m·K, wherein carbon fiber reinforced resin composites comprise a low density and high strength/modulus [0002-0005], wherein before the two differing materials are bonded the graphite film is subjected to plasma treatment which along with alkaline/acid washing provides a good interface for bonding [0025, 0031-0032, 0042].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a plasma treatment to the graphite film before coupling. One of ordinary skill in the art would have been motivated to provide a good interface for bonding [0025, 0031-0032, 0042].
Claims 17-18 are alternatively rejected under 35 U.S.C. 103 as being unpatentable over Mishiro in view of Duan, Chung, and optionally Deodati and Wable, as applied to claim 1 above, further in view of Guo et al. (Thermal management with a highly emissive and thermally conductive graphite absorber) (hereinafter “Guo”).
Regarding claims 17-18, in the event that thermal emissivity and solar absorptivity of the composite are not inherent/obvious as recited above:
Guo teaches a thermal management for industrial, solar, and electronic uses, wherein a pyrolytic graphite that is graphitized from a polyimide film and surface treated by etching can provide a hemispherical reflectance is around 1% in the visible range (450 nm to 850 nm) and less than 1% from 1.5 to 10 µm, such that absorbance/emissivity could be tuned in the visible and near to far-infrared regions, which would increase cooling and heat dissipation by several degrees even over CVD graphite or metal coated graphite [Abstract, Introduction, Conclusion].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the composite with a thermal emissivity and solar absorptivity as claimed. One of ordinary skill in the art would have been motivated to substantially improve cooling and heat dissipation in a pyrolytic graphite film [Abstract, Introduction, Conclusion].
Conclusion
The prior art made of record and not relied upon is considered pertinent to Applicant's disclosure:
Seki et al. (JP 2010-229238 A) teaches a flexible heat dissipating sheet comprising a high rigidity for supporting electronic displays [0003, 0021, 0026, 0043-0044], preferably comprising pitch-based carbon fibers [0022-0023], wherein the resin may comprise conductivity enhancing agents [0036]. This reference may be used in addition to or replacing that of Deodati as applied to Hayashi.
Liang et al. (Effect of Carbon Nanofibers on Thermal Conductivity of Carbon Fiber Reinforced Composites) teach the inclusion of nanofibers into the impregnating resin of carbon fiber reinforced composites to improve thermal conductivity along the in-plane and out-of-plane thickness directions.
Kandare et al. (Improving the through-thickness thermal and electrical conductivity of carbon fibre/epoxy laminates by exploiting synergy between graphene nanoplatelets and silver nanowires by loading the impregnating resin.
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to JEFFREY A VONCH whose telephone number is (571)270-1134. The Examiner can normally be reached M-F 9:30-6:00.
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If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Frank J Vineis can be reached at (571)270-1547. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JEFFREY A VONCH/Primary Examiner, Art Unit 1781 April 3rd, 2026
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