DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on November 07, 2025 has been entered.
Response to Amendment
The amendment filed on 11/07/2025 has been entered. Claims 11-21 are pending in the application.
Response to Arguments
Applicant’s arguments with respect to claim 11 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.
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.
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 11-12, 15-16, 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Kiriyama (JP 2012021238, machine translation used for citations) in view of Ma et al (CN 109385891 A, machine translation used for citations), Ichikawa et al (EP2910676A1), Tanaka et al. (US 20080152574), and Korzhenko (WO 2018078288 A1, machine translation used for citations).
Regarding claim 11, Kiriyama discloses a method for producing a carbon fiber bundle (Kiriyama [0012]) where the PAN-based precursor fiber bundle is heated in an oxidizing atmosphere at 200 to 300 °C, the oxidizing atmosphere such as air, oxygen (Kiriyama [0017] meeting limitation “performing an oxidation of the carbon fiber at 200-300°C”). This range is identical to the claimed range of 200-300 °C.
Example 1 discloses A PAN precursor fiber bundle … was continuously flame-retarded at a flame-retardant treatment temperature of 220 to 270 °C for 56 minutes, i.e. oxidation treatment, at an elongation rate of －6%, to obtain a flame-retardant fiber bundle having a density of 1.35 g/cm3 NER1 ([0038] meeting limitation “wherein an oxidation density is controlled at 1.30-1.42 g/cm3”).
Kiriyama further discloses a pre-carbonization step where the fiber bundle is placed in a first carbonization furnace and subjected to a pre-carbonization treatment where the first carbonization furnace is an inert atmosphere having a temperature of 300 °C or more and less than 1000 °C (Kiriyama [0024] meeting limitation “performing a first carbonization of the carbon fiber”).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the claimed range (400-800 °C) is inside the range taught by Kiriyama (300 to 1000 °C). Therefore, the range in Kiriyama renders obvious the claimed range.
Kiriyama further discloses the pre-carbonized fiber bundle is charged into a second carbonization furnace and carbonized where the second carbonization furnace has an inert atmosphere having a maximum temperature of 1000 °C or more and 3000 °C or less (Kiriyama [0025] meeting limitation “performing a second carbonization of the carbon fiber”).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the claimed range (900-2000 °C) overlaps the range taught by Kiriyama (1000 to 3000 °C). Therefore, the range in Kiriyama renders obvious the claimed range.
Kiriyama further discloses the carbonized fiber bundle subjected to a surface treatment with electrolytic oxidation treatment in an electrolyte as the surface treatment (Kiriyama [0026] meeting limitation “placing the carbon fiber as an anode in an electrolyte” and “performing a surface treatment”). A carbonized fiber bundle passed through an 8 mass % aqueous solution of nitric acid and a voltage of 8.4 V was applied to the carbonized fiber bundle, and an electric current of 18 C/g was passed through the bundle to perform a surface treatment (Kiriyama [0042]). This process necessarily introduces oxygen-containing groups to the surface given it is an oxidation surface treatment.
Kiriyama further discloses a sizing agent application treatment ([0031], meeting limitation “performing a sizing treatment”), the sizing agent contained in the sizing treatment liquid is not particularly limited, but examples thereof include epoxy resins ([0033]). The amount of the sizing agent attached to the carbon fiber bundle is… more preferably 0.4 to 3 mass % ([0034]).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the range taught by Kiriyama (0.4 to 3 mass %) overlaps with the claimed range (0.8-2.0% by weight). Therefore, the range in Kiriyama renders obvious the claimed range.
Kiriyama is silent to “wherein the carbon fibers contain an oil agent, and an amount of the oil agent is 0.5-3.0% by weight of the carbon fiber”, “wherein a carbonization density is controlled at 1.50-1.62 g/cm3”, “a surface oxygen concentration of the oxidized carbon fiber is 5-35%” and “a surface roughness of the oxidized carbon fiber is 5-25 nm”.
Tanaka discloses an oil agent for precursor fiber of carbon fiber ([0008]), for example polyacrylonitrile-based fiber ([0065]). The amount of deposition of the oil agent such that the ratio of the oil agent component except the liquid medium to the dry weight of the precursor fiber is preferably 0.1 to 5 wt %, still more preferably 0.5 to 2 wt % ([0073]).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the claimed range (0.5-3.0%) is inside the range taught by Tanaka (0.1 to 5 wt %). Therefore, the range in Tanaka renders obvious the claimed range.
Tanaka further discloses using the oil agent for carbon fiber precursor produces a carbon fiber of stable quality without a fuzz or fiber breakage ([0130]).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to provide a carbon fiber wherein the carbon fibers contain an oil agent in the process of Kiriyama in order to produce a carbon fiber of stable quality without a fuzz or fiber breakage as taught by Tanaka.
Korzhenko discloses a process for manufacturing a high-carbon fiber or a set of fibers… said process further comprising the following steps: ([0015]) a carbonization step of the fiber… in order to obtain a highly carbonized fiber or group of fibers ([0017]). Advantageously, this fiber or set of fibers has, after the carbonization step, a density between 0.20 and 1.95 g/cm3, preferably between 1.45 and 1.60 g/cm3 ([0029]). These products meet the expectations of manufacturers seeking lighter carbon fibers that nevertheless have sufficient mechanical properties, particularly to meet the needs of the aeronautical or automotive industries ([0029]).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the range taught by Korzhenko (1.45 and 1.60 g/cm3) overlaps with the claimed range (1.50-1.62 g/cm3). Therefore, the range in Korzhenko renders obvious the claimed range.
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art for a carbonization density to be controlled at 1.50-1.62 g/cm3 in the method of Kiriyama in order for the carbon fiber to be light and have sufficient mechanical properties to meet the needs of the aeronautical or automotive industries as taught by Korzhenko.
Ma discloses a method for modifying the surface of carbon fiber ([0002]), including an oxidation step ([0011]). Experimental results of Example 2 are as follows: ([0175]) changes in elements before and after carbon fiber modification: Compared with untreated carbon fiber, the oxygen content on the surface of CF-IPDI-MZ increased to 15.38% ([0176]), which is within the claimed range of 5-35%. Ma further discloses the interfacial shear strength of the carbon fiber with surface grafted curing agent imidazole prepared by the present invention is increased from 48.8 MPa of the original fiber to 61.3 MPa- 87.2 MPa ([0038]).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art for the surface oxygen concentration of the oxidized carbon fiber to be 5-35% in the method of Kiriyama in order to increase the interfacial shear strength as taught by Ma.
Ichikawa discloses a carbon fiber-reinforced resin composition having excellent interfacial adhesion between carbon fibers and a matrix resin and having excellent mechanical properties (abstract). Carbon fibers having a surface roughness of 6.0 nm to 60 nm are preferable because the carbon fibers have surfaces having a highly active edge part and thus the interaction with the epoxy group in the sizing agent is improved and the interfacial adhesion between the carbon fibers and the thermoplastic resin can be improved ([0114]).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the range taught by Ichikawa (6 nm to 60 nm) overlaps with the claimed range (5-25 nm). Therefore, the range in Ichikawa renders obvious the claimed range.
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art for the surface roughness of the oxidized carbon fiber to be 5-25 nm in the method of Kiriyama in to improve interfacial adhesion between the carbon fibers and the thermoplastic resin as taught by Ichikawa.
Regarding claim 12, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above including a voltage of 8.4 V applied (Kiriyama [0042]). 8.4 V is within the claimed range of 5-40 V. Kiriyama further discloses an electric current of 18 C/g was passed through the bundle to perform a surface treatment (Kiriyama [0042]). 18 C/g is within the claimed range of 3-40 coulombs/gram.
Regarding claim 15, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above including a voltage of 8.4 V applied (Kiriyama [0042]). 8.4 V is within the claimed range of 5-20 V.
Regarding claim 16, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above and further discloses polyacrylonitrile fiber is most suitable for producing carbon fiber precursor (Kiriyama [0031]).
Regarding claim 18, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above including a voltage of 8.4 V applied (Kiriyama [0042]). 8.4 V is within the claimed range of 5-40 V.
Regarding claim 19, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above including an electric current of 18 C/g was passed through the bundle to perform a surface treatment (Kiriyama [0042]). 18 C/g is within the claimed range of 3-40 coulombs/gram.
Claims 13 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Kiriyama (JP 2012021238, machine translation used for citations) in view of Ma et al (CN 109385891 A, machine translation used for citations), Ichikawa et al (EP2910676A1), Tanaka et al. (US 20080152574), and Korzhenko (WO 2018078288 A1, machine translation used for citations) with evidentiary support provided by Trask Instrumentation, Inc. (“Conductivity Chart of Liquids”, hereinafter “Trask”).
Regarding claim 13, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses the limitations as set forth above, including passing a carbonized fiber bundle through an 8 mass % aqueous solution of nitric acid (Kiriyama [0042]).
Trask discloses nitric acid at 6.2% by weight has conductivity of 312000 µS/cm, i.e. 312 mS/cm, and nitric acid at 12.4% by weight has conductivity of 542000 µS/cm, i.e. 542 mS/cm (Pg.7). The conductivity of nitric acid disclosed by Kiriyama at 8% by weight must necessarily be in the range of 312-542 mS/cm which is within the claimed range of 200 to 700 mS/cm.
Regarding claim 17, Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses the limitations as set forth above, including passing a carbonized fiber bundle through an 8 mass % aqueous solution of nitric acid (Kiriyama [0042]).
Trask discloses nitric acid at 6.2% by weight has conductivity of 312000 µS/cm, i.e. 312 mS/cm, and nitric acid at 12.4% by weight has conductivity of 542000 µS/cm, i.e. 542 mS/cm (Pg.7). The conductivity of nitric acid disclosed by Kiriyama at 8% by weight must necessarily be in the range of 312-542 mS/cm which is within the claimed range of 200 to 3000 mS/cm.
Claims 14 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kiriyama (JP 2012021238, machine translation used for citations) in view of Ma et al (CN 109385891 A, machine translation used for citations), Ichikawa et al (EP2910676A1), Tanaka et al. (US 20080152574), and Korzhenko (WO 2018078288 A1, machine translation used for citations), and in further view of Wang (CN 112941965, machine translation used for citations).
Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka discloses all the limitations in the claims as set forth above but is silent to wherein temperature of the electrolyte is controlled at 15-40°C (claim 14) and wherein a time for the surface treatment is 5-90 seconds (claim 20).
Wang discloses a preparation method of carbon fiber filter paper ([0001]) including performing electrochemical oxidation surface treatment on PAN-based first carbon fiber to obtain the second carbon fiber, so that a large number of oxygen-containing functional groups are formed on the fiber surface, which increases the grooves and surface area of the fiber surface, improves the surface energy and wetting properties of the fiber and further improves the hydrophilicity and dispersibility of the second carbon fiber in water ([0033]). The electrochemical oxidation surface treatment uses ammonium bicarbonate as the electrolyte solution, the electrolysis temperature is 30 °C, and the electrolysis time is 60-180s ([0054]). The electrolysis temperature of 30 °C is within the claimed range of 15-40°C.
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the electrolysis time range taught by Wang (60-180s) overlaps with the claimed range (5-90 seconds). Therefore, the range in Wang renders obvious the claimed range.
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to have the temperature of the electrolyte is controlled at 15-40°C (claim 14) and a time for the surface treatment is 5-90 seconds (claim 20) in the process of Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka in order to improve the surface energy and wetting properties of the fiber and further improve the hydrophilicity and dispersibility of the carbon fiber in water as taught by Wang.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Kiriyama (JP 2012021238, machine translation used for citations) in view of Ma et al (CN 109385891 A, machine translation used for citations), Ichikawa et al (EP2910676A1), Tanaka et al. (US 20080152574), and Korzhenko (WO 2018078288 A1, machine translation used for citations), and in further view of Gulyas et al. ("Electrochemical oxidation of carbon fibres: surface chemistry and adhesion") with evidentiary support provided by Trask Instrumentation, Inc. (“Conductivity Chart of Liquids”, hereinafter “Trask”).
Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka with evidentiary support by Trask discloses all the limitations in the claims as set forth above including a conductivity value of the electrolyte is 250-700 mS/cm and an electricity amount supplied in the surface treatment is 15-25 coulombs/gram.
Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka with evidentiary support by Trask is silent to “wherein the electrolyte is the sulfuric acid, the ammonium bicarbonate, or the phosphoric acid”.
Gulyas discloses PAN based carbon fiber subjected to electrochemical oxidation where sulfuric acid and nitric acid were used as electrolytes (Pg. 354 Section 2. Experimental Par. 1). Gulyas further discloses fiber strength is higher at gauge length 15mm when sulfuric acid is used compared to nitric acid (Table 2).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to use electrolyte sulfuric acid, the ammonium bicarbonate, or phosphoric acid in the process of Kiriyama in view of Ma, Ichikawa, Korzhenko and Tanaka with evidentiary support by Trask in order to increase fiber strength at 15 mm gauge length as taught by Gulyas.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICOLE L QUIST whose telephone number is (571)270-5803. The examiner can normally be reached Mon-Fri 8:30-5:00.
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/N.L.Q./Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738