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 .
Response to Amendment
The response filed 22 July 2026 has been entered.
Claims 1-25 remain pending in the application, wherein claims 12-25 have been withdrawn. None of the claims have been amended.
Response to Arguments
Applicant's arguments filed 22 July 2026 have been fully considered but they are not persuasive for the following reasons:
Applicant argues, see p. 7, that the different porosity metrics are incorrectly equated, but does not provide evidence that the method of measuring the porosity or the difference of mercury penetration method (as compared to the instantly claimed mercury porosimetry method) results in an objectively different structure.
Applicant further argues, see p. 7, that the rejection relies upon a visual interpretation of a graph instead of a required mathematical calculation. It is not clear what mathematical calculation is required as none are recited in the claims. It is additionally acknowledged that the USPTO does not have facilities to reproduce the product of the prior art and perform measurements according to an Applicant’s specification and therefore must rely on what is disclosed in the prior art (e.g. graphs and descriptions). In this regard, the rejection in the Office Action mailed 28 January 2026 outlines that Takayasu teaches having a predominantly open porosity and an average pore diameter of 2 µm or less (Col. 3, l. 55-58), which overlaps the instantly claimed range (i.e. “or less” includes an average pore diameter being 0.1 µm, or 0.01 µm, and would therefore have a low fraction, i.e. an overlapping amount, of pores having a diameter of 0.4 µm or greater). See MPEP § 2144.05.
Applicant argues, see p. 8, that the claimed porosity is directly correlated with reduced oil penetration and oxidative consumption. However, this argument is not commensurate in scope with the instant claims because the claims are directed to a C/C composite in general, which does not require (explicitly or inherently) that it would lead to oil penetration or oxidative consumption.
Applicant argues, see p. 8, that Takayasu teaches away from the claimed densification process that leads to the claimed properties. However, the claims are directed to a C/C composite, not a process, and therefore are not limited to any recited (or argued) steps, only the product implied by such steps. See MPEP § 2113(I). Applicant further argues that without such densification step, the claimed open porosity may not be achieved. However, this argument lacks objective evidence to support it. See MPEP § 2145(I).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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.
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.
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 1-7, 9, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Takayasu et al. (US 5,665,464, previously cited).
Claim 1: Takayasu teaches a carbon fiber-reinforced carbon composite (i.e. a “C/C composite”) in which reinforcing carbon fibers are unidirectionally oriented and dispersed within a matrix of carbon (Col. 1, lines 9-17). Takayasu teaches that the volume of pores having a pore diameter of 10 µm or more should be 5% or less of the total pore volume of the composite material, with open pores accounting for at least 90% of the total pore volume (i.e. open porosity; open pores) (Col. 3, lines 41-55). The pore diameter overlaps the instantly claimed range (i.e. a diameter of 10 µm is a radius of 5 µm) and the pore volume overlaps the instantly claimed range. The courts have held that a prima facie case of obviousness exists where claimed ranges overlap, lie inside of, or are close to the ranges in the prior art. See MPEP § 2144.05. It is noted that as of the writing of this Office Action, no demonstration of a criticality to the claimed ranges has been presented. Takayasu further teaches that it is preferred that pores contained in the composite material have an average pore diameter of 2 µm or less and a total pore volume of 0.13 cc/g or ess (Col. 3, lines 55-58). The average pore diameter overlaps the instantly claimed range and the teaching of “or less” for the range of total pore volume also overlaps the instantly claimed range. See MPEP § 2144.05. Takayasu does not specify the measurement as being by mercury porosimetry, but this limitation is considered a product-by-process limitation (i.e. how to measure the porosity) and therefore is not limited to the manipulations of the recited steps, only the structure implied by the steps. See MPEP § 2113. Takayasu does teach, however, that the pore volume and pore diameter are measured according to mercury penetration method (Col. 2, lines 59-63).
While not reciting a singular example of the instantly claimed C/C composite, it would have been obvious to one of ordinary skill in the art before the effective filing date as Takayasu teaches ranges of pore volume and size that overlaps the instantly claimed ranges which the courts have held to be prima facie obvious, and one would have had a reasonable expectation of success.
Claim 2: Takayasu shows the relationship of pore diameter with relative pore volume in Fig. 1 (i.e. since open pores account for at least 90% of the total pore volume as taught by Takayasu at Col. 3, lines 41-55, then the change in relative pore volume is proportional to change in open porosity), and the pore radius at which the distribution curve starts to rise as at about 2-3 µm for curve 1 and about 5 µm for curve 2 (Fig. 1). These values overlap or are close to the instantly claimed range. See MPEP § 2144.05.
Claim 3: Takayasu teaches the carbon fibers to be impregnated with suspension of resin and unidirectionally aligned before curing and calcining (Col. 2, lines 45-63), which is comparable to the preparation of the instant disclosure (paragraphs 0079-0080 of the instant specification). Therefore, the composite of Takayasu is considered to have the instantly claimed property of number of open pores along a direction of fibers being larger than a number of open pores along a direction orthogonal to the direction of fibers, because substantially identical materials treated in substantially identical manner have substantially identical properties and functions. See MPEP § 2112.01.
Claim 4: Takayasu teaches that the content of carbon fibers should be at least 50%, preferably 55-85% based on volume (Col. , lines 41-44), which overlaps the instantly claimed range. See MPEP § 2144.05. Takayasu does not teach this content to be determined by image analysis, but this limitation is considered to be a product-by-process limitation (i.e. how to measure the carbon fiber volume content) and therefore is not limited to the manipulations of the recited steps, only the structure implied by the steps. See MPEP § 2113.
Claim 5: Takayasu teaches that any continuous carbon fibers may be used, such as mesophase pitch-derived carbon fibers (Col. 5, lines 1-7).
Claim 6: Takayasu teaches that the cured composite is carbonized and then graphitized (Col. 5, line 64 to Col. 6, line 7) (i.e. at least part of the open pores are densified by a densifying material).
Claim 7: Takayasu teaches that the cured composite is carbonized in a nitrogen flow and then graphitized (Col. 5, line 64 to Col. 6, line 7) (i.e. part of the densifying material is carbon; i.e. being carbonized under nitrogen (gas) flow is considered to be a chemical vapor infiltration process).
Claim 9: Takayasu teaches that the carbon fibers (i.e. having open porosity) are impregnated with carbonaceous powder and thermosetting resin (Col. 4, lines 40-49), wherein carbonaceous powder may be derived from pitch (Col. 3, line 66 to Col. 4, line 9) (i.e. pitch-derived carbonaceous matter and/or thermosetting resin may be considered densifying material as these materials are impregnated in (the pores of) the carbon fibers).
Claim 11: Takayasu teaches a carbon fiber-reinforced carbon composite (i.e. a “C/C composite”) in which reinforcing carbon fibers are unidirectionally oriented and dispersed within a matrix of carbon (Col. 1, lines 9-17) (i.e. a unidirectional C/C composite since the carbon fibers are unidirectionally oriented). Takayasu teaches dipping a bundle or tow of the carbon fibers in suspension, arranging and drying the bundles in parallel to form a sheet, and then placing the dried sheets in a mold cavity such that the fibers are oriented in one direction (Col. 5, lines 8-24). While not teaches specifically the instantly claimed pultrusion molding, this limitation is considered to be a product-by-process limitation (i.e. for obtaining a molded body with unidirectionally oriented carbon fibers) and therefore is not limited to the manipulations of the recited steps, only the structure implied by the steps. See MPEP § 2113.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Takayasu et al. (US 5,665,464, previously cited) as applied to claim 6 above, and further in view of Kirkpatrick et al. (US 2019/0292107, previously cited).
Claim 8: The teachings of Takayasu regarding claim 6 are outlined above. Takayasu teaches a carbon fiber-reinforced carbon composite (i.e. a “C/C composite”) in which reinforcing carbon fibers are unidirectionally oriented and dispersed within a matrix of carbon (Col. 1, lines 9-17). However, Takayasu does not teach the instantly claimed silicon carbide densifying material.
In a related field of endeavor, Kirkpatrick teaches a carbon/carbon composite that is infiltrated to form a densified fibrous structure (paragraph 0003). The fibrous structure may be infiltrated with silicon to form a silicon carbide infiltrated fibrous structure to obtain a bulk density of 2.0-2.5 g/cc and less than about 3% open porosity (paragraph 0003).
As Takayasu and Kirkpatrick both teach a carbon-carbon composite, they are analogous. It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the C/C composite of Takayasu to include infiltrating with silicon to form a silicon carbide infiltrated structure (i.e. at least part of the densifying material is silicon carbide) as this is considered use of a conventionally known technique to improve similar devices in the same way, and one would have had a reasonable expectation of success. See MPEP § 2143(I)(C).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Takayasu et al. (US 5,665,464, previously cited) as applied to claim 6 above, and further in view of Murphy (US 2008/0199681, previously cited).
Claim 10: The teachings of Takayasu regarding claim 6 are outlined above. Takayasu teaches a carbon fiber-reinforced carbon composite (i.e. a “C/C composite”) in which reinforcing carbon fibers are unidirectionally oriented and dispersed within a matrix of carbon (Col. 1, lines 9-17). However, Takayasu does not teach the instantly claimed silicon carbide densifying material.
In a related field of endeavor, Murphy teaches a carbon/carbon composite (paragraph 0004) as a body having a ceramic material within pores of the body (paragraphs 0012 and 0015-0016). The ceramic material is deposited within the pores, reacted as an initial ceramic material with monoaluminum phosphate, or by vitrifying monoaluminum phosphate within the pores (paragraphs 0022-0024). Acid phosphate may react in the pores in the presence of a metal oxide to form the ceramic material which is a chemically bonded phosphate ceramic (paragraph 0071), wherein the metal oxide is preferably aluminum oxide etc. (paragraph 0073), wherein the acid phosphate is preferably monoaluminum phosphate (paragraph 0066). The body preferably has a porosity of 5-40% by volume before introduction or formation of chemically bonded phosphate ceramic (paragraph 0082), and the chemically bonded phosphate ceramic may partially or completely fill some or all of the pores of the porous body (paragraph 0078) (i.e. the result is the porous body being densified by a densifying material that may include aluminum phosphate because the phosphate ceramic is more dense than the voids of the pores; i.e. the resulting porosity is lower than the initial 5-40% and may be near zero if all the pore are completely filled).
As Takayasu and Murphy both teach a carbon-carbon composite, they are analogous. It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the C/C composite of Takayasu to include introduction or formation of chemically bonded phosphate ceramic in the pores of the composite body by vitrifying monoaluminum phosphate or by reacting monoaluminum phosphate and aluminum oxide (i.e. at least part of the densifying material is aluminum phosphate or a mixture of aluminum phosphate and aluminum oxide) as this is considered use of a conventionally known technique to improve similar devices in the same way, and one would have had a reasonable expectation of success. See MPEP § 2143(I)(C).
Conclusion
THIS ACTION IS MADE FINAL. 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 KIM S HORGER whose telephone number is (571)270-5904. The examiner can normally be reached M-F 9:30 AM - 4:00 PM EST.
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/KIM S. HORGER/Examiner, Art Unit 1784
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