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
Examiner acknowledges Applicant’s response filed 15 October 2025 containing remarks and amendments to the claims.
Claims 1, 4-10, and 12-18 are pending, with claims 12-18 withdrawn from consideration.
The previous rejections have been updated as necessitated by amendments to the claims.
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 1 and 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Isayev (US 7,018,526) in view of Tsuchitani (US 5,182,011) and Romine (US 5,489,374).
Regarding claim 1, Isayev teaches blending isotropic pitch with mesophase pitch at temperatures of 400˚C (column 11-column 12). Isayev teaches that appropriate heat soaking times may be selected (column 5, lines 30-64). Therefore, it would have been obvious to the person having ordinary skill in the art to have selected appropriate durations, in order to obtain the desired products. Isayev teaches isotropic pitch having softening point of 118˚C (table 1), which Examiner considers to be close enough to the claimed range of 120˚C, that the same or similar properties would be present. Further, Isayev teaches that further heat treatment may be performed in order to raise the softening point temperature (see table 1). Isayev teaches that properties of the products can be adjusted by heat soaking duration, and selection of amounts of each component (columns 5-11, see examples).
Isayev does not explicitly disclose (1) hydrogenation steps to obtain the mesophase pitch (2) thermal polymerization of the isotropic feed.
Regarding (1), Tsuchitani teaches a method for preparing mesophase pitch by hydrogenation of heavy oils with tetralin solvent followed by heat treatment, solvent extraction, filtering, and drying (column 5, lines 1- column 6, lines 60). Tsuchitani teaches the heavy oil feed can be vacuum resid, or products from cracking, or pyrolysis oils (column 3, lines 30-40). Tsuchitani teaches that heat treatment can be performed in the presence of inert gas a temperature of 350-500°C under reduced or normal pressure (column 12, lines 45-55). Tsuchitani teaches heat treatment in a thin film evaporator (column 35, lines 1-20). Tsuchitani teaches the mesophase is liquid crystals (column 3, lines 45-47). Examiner notes that it would have been obvious to the person having ordinary skill in the art to have selected appropriate inert gas flow rates, in order to achieve the desired pitches.
Therefore, it would have been obvious to the person having ordinary skill in the art to have performed the Tsuchitani steps in order to form the mesophase feed required by Isayev.
Regarding (2), Romine teaches sending isotropic pitch to pressurized heat soaking followed by evaporation in order to obtain materials suitable for carbon fibers (column 1, lines 1-65 and column 4 – column 6, see pressure in examples). Romine teaches petroleum feedstocks including decant oil and heavy distillates (column 3, line60-column 4, line4). Romine teaches temperatures of 360-550˚C (column 4, lines 28-50). Romine teaches operating until the pitch is entirely isotropic (column 4, lines 49-56). Examiner additionally notes that it is expected that appropriate pressures would be selected as known in the art in order to recover the desired isotropic phase.
Therefore, it would have been obvious to the person having ordinary skill in the art to have performed the Romine steps to obtain controlled softening point isotropic feeds, that may be used in the process of Iseyev as carbon fiber precursors.
Since the prior art teaches the same process steps as claimed, it is expected that the same products in the same yield would be obtained.
Regarding claims 4-5, Tsuchitani teaches hydrogenation temperatures of 350-500°C using tetralin or tetrahydroquinoline solvent and 1-5 times amount of solvent (column 33, lines 24-65) at a residence time of 10-120 min (column 34, lines 1-10).
Regarding claims 6-7, Tsuchitani teaches selecting appropriate heat treatment conditions including temperatures of 350-500°C (column 12, lines 45-55), and selection of inert gas rates and raw material rate (see table 3) and residence times (see examples) and pressures (column 12, lines 45-55).
Therefore, it would have been obvious to the person having ordinary skill in the art to have appropriately selected residence time, temperature, and inert gas flow rates, for the benefit of obtaining the desired formation of mesophase pitch.
Regarding claim 8, Tsuchitani teaches the same process steps applied to the same feed, therefore it is expected that the same or similar softening point and pitch content properties would result. Further, Tsuchitani teaches recovering 100% mesophase content (column 49, lines 40-50).
Regarding claim 9, Tsuchitani teaches solvent extraction using 1-5 times weight solvent per pitch component (column 28, lines 55-66).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Isayev (US 7,018,526) in view of Tsuchitani (US 5,182,011) and Romine (US 5,489,374), as applied to claim 1 above, and further in view of Lahijani (US 4,990,285).
Regarding claim 10, the previous combination teaches the limitations of claim 1, as discussed above. Tsuchitani teaches solvent extraction using 1-5 times weight solvent per pitch component (column 28, lines 55-66).
Tsuchitani does not explicitly disclose tetrahydrofuran as the solvent.
However, Lahijani teaches a similar method for solvent extraction to recover mesophase components. Lahijani teaches that in addition to toluene and tetralin, tetrahydrofuran may be used in the solvent extraction step to recover mesophase in solvent to pitch ratios of 1:1 to 2:1 (column 4, lines 40-68).
Therefore, it would have been obvious to the person having ordinary skill in the art to have substituted the Lahijani solvent for the Tsuchitani aromatic solvent, since Lahijani teaches that THF recovers the same mesophase as desired by Tsuchitani.
Response to Arguments
Applicant’s arguments have been fully considered and are addressed by the updated rejections, as necessitated by amendments to the claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Mochida (Blending mesophase pitch to improve its properties as a precursor for carbon fiber) – previously relied on, teaches Mochida teaches mixing petroleum derived mesophase pitch with isotropic pitch at 360°C for 10 min in order to form a precursor for carbon fibers (page 670 experimental details). Mochida teaches using 30% isotropic component (page 673), which reads on the claimed range.
Yao (Tailoring Structures and properties of mesophase pitch based carbon fibers) – teaches blending mesophase with isotropic pitch
Romine (US 2002/0011427) – previously relied upon, teaches mixing mesophase with solvent
Saver (US 2004/0168612) – previously relied upon, teaches formation of aromatic solvent
Uemura (US 4,575,411) – previously relied upon, teaches hydrogenation of a heavy oil, followed by heat treatment to obtain pitch composition 2 (column 4, lines 20-45). Pitch 2 is subject to a thin film evaporation step, and precursor pitch is obtained which is suitable for melt spinning steps (column 5, lines 40-50).
DIckakian (US 4,219,404) – previously relied upon, teaches that solvent fractions are separated from solvent insoluble fractions by well-known techniques including solvent treatment, filtration, etc (column 5, lines 25-39).
Yamada (US 4,606,808) – previously relied upon, teaches hydrogenation temperatures of about 400°C with aromatic solvents (column 2, lines 20-49).
Romine (US 5,032,250) – previously relied upon, teaches THF or tetralin solvent treatment of pitch (columns 3-4).
Tamaki (US 5,356,574) – teaches producing pitch based fibers (abstract).
Smith (US 2019/0382664) – teaches modification of temperature dependence of pitch viscosity (abstract).
Tsuchitiani (US 5,182,011) – teaches preparing pitch by hydrogenation, solvent extraction, and filtration.
Romine (US 4,931,162) -teaches process for producing mesophase pitch (abstract).
Chen (US 2013/0228493) – teaches low and high softening point pitches and falling film reactors (see figure).
Romine (US 5,540,903) – teaches making carbon artifacts from solvated mesophase pitch (abstract).
Malone (US 7,318,891) – teaches thermal polymerization to produce pitch (abstract).
Sumner (US 5,614,164) – teaches production of mesophase pitch by TFE with inert gas (abstract).
Kalback (US 5,259,947) – teaches production of solvated mesophase (abstract).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHELLE STEIN whose telephone number is (571)270-1680. The examiner can normally be reached Monday-Friday 8:30 AM-5:00 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Prem C Singh can be reached at 571-272-6381. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/MICHELLE STEIN/Primary Examiner, Art Unit 1771