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 .
DETAILED ACTION
This Office action is in response to the communication filed on 10/07/2025. Currently claims 1-19 are pending in the application; with claims 12-19 withdrawn from consideration.
ELECTION / RESTRICTION
Applicant's election of Group I, claims 1-11, without traverse, drawn to a method in the reply filed on 10/07/2025 is acknowledged.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 103 that form the basis for the rejections under this section made 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 non-obviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5 are rejected under 35 U.S.C.103 as being obvious over Daumit et al. (US Patent Number 4,981,752), hereafter, referred to as “Daumit”, in view of Lee (Lee et al.: “Structure and tensile properties of textile-grade PAN fiber and its carbon fiber”, e-Polymers 2014; 14(3), Page 217–224), hereafter, referred to as “Lee”, in view of Taylor (US Patent Application Publication Number 2016/0186365 A1), hereafter, referred to as “Taylor”, as evidenced by Furushima et al. (Furushima et al.: ”Study of melting and crystallization behavior of polyacrylonitrile using ultrafast differential scanning calorimetry”, Polymer 55 (2014) Page 3075-3081), hereafter, referred to as “Furushima”.
Regarding claim 1, Daumit teaches in Fig. 1, a method of producing melt-spun polyacrylonitrile fibers which are well suited for thermal conversion to high strength carbon fibers. Daumit teaches that the method of producing polyacrylonitrile (PAN)-based carbon fibers comprises of extruding a PAN dope through a spinneret to produce a tow of PAN fibers having a lobed cross section; by teaching in (Column 9, lines 46-55) that in addition to substantially circular cross-sections, predetermined substantially uniform non-circular cross sections may be formed. Preferred non-circular cross sections include multi-lobed (e.g., 3 to 6 lobes). The glass transition temperature of the polyacrylonitrile (where the PAN homopolymer was purchased from Aldrich Co. (CAS:25014-41-9 C3H3N)) has been shown (evidenced) by Furushima to be in the range of 109-129 °C satisfying the claimed requirement of a glass transition temperature above 100 °C for PAN (abstract).
Daumit also teaches washing, drying and winding the tow of PAN fibers by teaching that the acrylic fibers formed by wet spinning wherein the as-spun fibers are coagulated with shrinkage, washed while being stretched, dried, and stretched prior to being used as a precursor for carbon fiber production (column 1, lines 36-40). But Daumit fails to explicitly teach that the process comprises of step without subjecting the PAN fibers to hot drawing at a temperature at or above 100° C. However, Lee teaches that carbon fibers were prepared using polyacrylonitrile material, which were 200% to 400% drawn in a hot water bath at 90°C. X-ray diffractograms confirmed that the drawing process led to higher crystallinity and molecular orientation. These fibers were stabilized at 25–255°C for 390 min, and carbonized to obtain carbon fibers. The tensile strength of resulting Carbon Fibers showed an improved tensile strength (abstract). Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the claimed invention, to incorporate the teaching of Lee and combine a drawing step without subjecting the PAN fibers to hot drawing at a temperature at or above 100° C, because that would result in Carbon Fibers with improved tensile strength. Since the reference deal with Polyacrylonitrile-based carbon fibers, one would have reasonable expectation of success from the combination.
Daumit teaches in (Column 10, lines 64 to Column 11, line 68) that the PAN multifilament material needs to be subjected to stabilization, drawing and carbonization in order to obtain lobed carbon fibers. Lee also teaches the stabilization and carbonization step in order to obtain the carbon fibers. But the references fail to explicitly teach that the carbonizing of the tow of PAN fibers at a temperature of less than 1,000° C to produce PAN-based carbon fibers. However, Taylor teaches in (para. [0045]) that the carbonization occurs in an inert (oxygen-free) atmosphere inside one or more specially designed furnaces; followed by carbonization by passing the fiber through a furnace heated to a higher temperature of from about 700-1650 °C. Taylor also teaches that the present process relates to carbon fibers having improved tensile strength and tensile modulus (para. [0002]). Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the claimed invention, to incorporate the teaching of Taylor, and combine a step of carbonizing of the tow of PAN fibers at a temperature of less than 1,000° C to produce PAN-based carbon fibers, because that would result in Carbon Fibers with improved tensile strength and tensile modulus. Since the reference deal with Polyacrylonitrile-based carbon fibers, one would have reasonable expectation of success from the combination.
Regarding claim 2, Daumit teaches a process, that includes using a spinneret with a +-shaped opening to produce PAN fiber filaments having a cross section with a lobed shape (multi-lobed (e.g., 3 to 6 lobes; Column 9, lines 46-55).
Regarding claim 3, Lee teaches a process, wherein the stabilizing includes heating the tow of PAN fibers to 240°-280° C; by teaching that the fibers were stabilized in a convection oven at 25–255°C. Additionally, Taylor also teaches a oxidation (equivalent to stabilization) step, where the oven temperature may range from 200° C. to 300° C., preferably 220 to 285° C (para. [0044]).
Regarding claims 4-5, Taylor teaches a process, wherein a highest fiber temperature reached during carbonization is between 850° C and 950° C (as claimed in claim 4), and between 885° C and 915° C (as claimed in claim 5); by teaching that during the carbonization step, the fiber passes through a furnace heated to a temperature of from about 700° C to about 1650° C.
Claims 6-11 are rejected under 35 U.S.C.103 as being obvious over Daumit et al. (US Patent Number 4,981,752), in view of Lee (Lee et al.: “Structure and tensile properties of textile-grade PAN fiber and its carbon fiber”, e-Polymers 2014; 14(3), Page 217–224), in view of Taylor (US Patent Application Publication Number 2016/0186365 A1), in view of Shimazaki et al. (JP 2003 239 157 A), hereafter, referred to as “Shimazaki”, as evidenced by Furushima et al. (Furushima et al.: ”Study of melting and crystallization behavior of polyacrylonitrile using ultrafast differential scanning calorimetry”, Polymer 55 (2014) Page 3075-3081).
Regarding claim 6, Daumit teaches in Fig. 1, a method of producing melt-spun polyacrylonitrile fibers which are well suited for thermal conversion to high strength carbon fibers. Daumit teaches that the method of producing polyacrylonitrile (PAN)-based carbon fibers comprises of extruding a PAN dope through a spinneret to produce a tow of PAN fibers having a lobed cross section; by teaching in (Column 9, lines 46-55) that in addition to substantially circular cross-sections, predetermined substantially uniform non-circular cross sections may be formed. Preferred non-circular cross sections include multi-lobed (e.g., 3 to 6 lobes). The glass transition temperature of the polyacrylonitrile (wherein the PAN homopolymer was purchased from Aldrich Co. (CAS:25014-41-9 C3H3N)) has been shown (evidenced) by Furushima to be in the range of 109-129 °C satisfying the claimed requirement of a glass transition temperature above 100 °C for PAN (abstract).
Daumit also teaches washing, drying and winding the tow of PAN fibers by teaching that the acrylic fibers formed by wet spinning wherein the as-spun fibers are coagulated with shrinkage, washed while being stretched, dried, and stretched prior to being used as a precursor for carbon fiber production (column 1, lines 36-40). But Daumit fails to explicitly teach that the process comprises of step without subjecting the PAN fibers to hot drawing at a temperature at or above 100° C. However, Lee teaches that carbon fibers were prepared using polyacrylonitrile material, which were 200% to 400% drawn in a hot water bath at 90°C. X-ray diffractograms confirmed that the drawing process led to higher crystallinity and molecular orientation. These fibers were stabilized at 25–255°C for 390 min, and carbonized to obtain carbon fibers. The tensile strength of resulting Carbon Fibers showed an improved tensile strength (abstract). Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the claimed invention, to incorporate the teaching of Lee and combine a drawing step without subjecting the PAN fibers to hot drawing at a temperature at or above 100° C, because that would result in Carbon Fibers with improved tensile strength. Since the reference deal with Polyacrylonitrile-based carbon fibers, one would have reasonable expectation of success from the combination.
Daumit teaches in (Column 10, lines 64 to Column 11, line 68) that the PAN multifilament material needs to be subjected to stabilization, drawing and carbonization in order to obtain lobed carbon fibers. Lee also teaches the stabilization and carbonization step in order to obtain the carbon fibers. But the references fail to explicitly teach that the carbonizing of the tow of PAN fibers at a temperature of less than 1,000° C to produce PAN-based carbon fibers. However, Taylor teaches in (para. [0045]) that the carbonization occurs in an inert (oxygen-free) atmosphere inside one or more specially designed furnaces; followed by carbonization by passing the fiber through a furnace heated to a higher temperature of from about 700-1650 °C. Taylor also teaches that the present process relates to carbon fibers having improved tensile strength and tensile modulus (para. [0002]). Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the claimed invention, to incorporate the teaching of Taylor, and combine a step of carbonizing of the tow of PAN fibers at a temperature of less than 1,000° C to produce PAN-based carbon fibers, because that would result in Carbon Fibers with improved tensile strength and tensile modulus. Since the reference deal with Polyacrylonitrile-based carbon fibers, one would have reasonable expectation of success from the combination.
But the prior art of references does not recognize the weaving of the carbon fibers to form fabric. However, Shimazaki teaches a PAN based carbon fiber spun yarn woven fabric (abstract). Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the claimed invention, to incorporate the teaching of Shimazaki, and combine the feature of weaving carbon fiber when it is desired to produce a lobed carbon fiber fabric. Since the reference deal with Polyacrylonitrile-based carbon fibers, one would have reasonable expectation of success from the combination.
Regarding claim 7, Daumit teaches a process, that includes using a spinneret with a +-shaped opening to produce PAN fiber filaments having a cross section with a lobed shape (multi-lobed (e.g., 3 to 6 lobes; Column 9, lines 46-55).
Regarding claim 8, Lee teaches a process, wherein the stabilizing includes heating the woven PAN fiber fabric to 265° C; by teaching that the fibers were stabilized in a convection oven at 25–255°C. Additionally, Taylor also teaches a oxidation (equivalent to stabilization) step, where the oven temperature may range from 200° C. to 300° C., preferably 220 to 285° C (para. [0044]).
Regarding claims 9-10, Taylor teaches a process, wherein a highest fiber temperature reached during carbonization is between 850° C and 950° C(as claimed in claim 9), and between 885° C and 915° C (as claimed in claim 10); by teaching that during the carbonization step, the fiber passes through a furnace heated to a temperature of from about 700° C to about 1650° C.
Regarding claim 11, Daumit teaches a process, that includes using a spinneret with a +-shaped opening to produce PAN fibers having a cross section with a lobed shape (multi-lobed (e.g., 3 to 6 lobes; Column 9, lines 46-55).
Examiner’s Note
The examiner included a few prior arts which were not used in the rejection but are relevant to the disclosure.
US 2017/0275786 A1 (Kumar et al.) – Kumar teaches in Fig. 1, a method of making a carbon fiber, comprising the steps of: (a) dissolving PAN (poly(acrylonitrile-co methacrylic acid)) into a solvent to form a PAN solution; (b) extruding the PAN solution through a spinneret, thereby generating at least one precursor fiber; ( c) passing the precursor fiber through a cold gelation medium, thereby causing the precursor fiber to gel; (d) drawing the precursor fiber to a predetermined draw ratio; (e) continuously stabilizing the precursor fiber to form a stabilized fiber; (f) continuously carbonizing the stabilized fiber thereby generating the carbon fiber; and (g) winding the carbon fiber onto a spool (claim 8).
US 5,154,908 (Edie et al.) – Edie teaches in Fig. 1, A method for producing a high elastic modulus, high tensile strength carbon fiber, comprising: providing a molten precursor containing a substantial proportion of carbonaceous anisotropic material; maintaining the molten precursor at a temperature such that the viscosity of the molten precursor falls within the range between about 250 poise and about 2000 poise; extruding said molten precursor through a spinneret defining a capillary having at least one lobe-shaped cross-sectional area; solidifying the extruded precursor as it emerges from the spinneret, into a fiber filament having a transverse cross-section substantially like the transverse cross-section of said capillary; rendering the fiber filament infusible; and thereafter heating the fiber filament in an inert environment at a temperature sufficient to substantially increase the tensile strength and modulus of elasticity of the fiber filament (claim 11).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOHAMMAD M AMEEN whose telephone number is (469) 295 9214. The examiner can normally be reached on M-F from 9.00 am to 6.00 pm (Eastern Time).
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/MOHAMMAD M AMEEN/Primary Examiner, Art Unit 1742