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 .
StatusClaims(s) 1-3, is/are filed on 9/27/2024 are currently pending. Claim(s) 1-3 is/are rejected.
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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under pre-AIA 35 U.S.C. 103(a) 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.
Claim(s) 1 is/are rejected under 35 U.S.C. 103 as being unpatentable over MIYATA (WO 2020/059344 A1 citations from US 20220054987 A1) in view of HAYASHI (WO 2020/084930 A1 citations from US 20210379537 A1).
Regarding claim 1, MIYATA discloses a hollow fiber membrane (filtration layer (1)) comprising polytetrafluoroethylene as a main component ([0021], a porous tubular filtration layer with PTFE as the main component). MIYATA further discloses: an average thickness of 0.60 mm or less — Example No. 1 is a single filtration layer (1) having an average thickness (T) of 0.3 mm ([0075]); and an isopropanol bubble point of 90 kPa or more — the IPA bubble point of membrane No. 1 was measured at 104 kPa per ASTM F316 ([0078]). MIYATA does not state the average outer diameter of 2.10 mm or less. HAYASHI is directed to a PTFE or modified-PTFE hollow fiber membrane (1) and teaches an average outer diameter (D2) with an upper limit of 1.0 mm ([0047]) and an average thickness (T1) with an upper limit of 0.5 mm ([0049]). Those values fall within the claimed “2.10 mm or less” and “0.60 mm or less.”
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to make the hollow fiber membrane (1) of MIYATA with an average outer diameter of 2.10 mm or less, as taught by HAYASHI, in order to reduce membrane size while keeping filtration performance. Choosing an outer diameter in the claimed range is no more than finding an optimum or workable value of a known variable by routine testing, unless Applicant shows that the range is critical or gives unexpected results. See MPEP 2144.05(II); In re Aller, 220 F.2d 454 (CCPA 1955); MPEP 2144.04 (changes in size).
MIYATA does not teach a degree of orientation (72%–85%) and heat of fusion (10.0–13.4 J/g at about 328 °C). However, Example No. 1 is made from the same starting materials used in the working examples of the present specification — PTFE fine powder “F104” (Daikin) and liquid lubricant “FP-25”/“Supersol FP-25” (Idemitsu, naphtha) (compare MIYATA [0074] with specification) — and by the same sequence of steps (extrusion, stretching in the length direction, and firing at 365 °C for 6 minutes; MIYATA [0075]). The 365 °C firing is inside the 330 °C–370 °C heat-treatment window that the specification says gives the claimed orientation and heat of fusion (specification [0042]). Where the claimed product and the prior art product are made by the same or substantially the same process from the same materials, the claimed properties are presumed to be present, and the burden shifts to Applicant to show a difference. See MPEP 2112.01(I)–(II); In re Best, 562 F.2d 1252 (CCPA 1977); In re Spada, 911 F.2d 705 (Fed. Cir. 1990) (“products of identical chemical composition cannot have mutually exclusive properties”). Therefore, the degree of orientation in the longitudinal direction by wide-angle X-ray scattering (72% to 85%) and the amount of heat of fusion at the endothermic peak in the vicinity of 328 °C (10.0 J/g to 13.4 J/g) are taken as properties of the membrane (1) of MIYATA and therefore inherent.
Alternatively, these are also well-known properties. Yasuda (US 10456753 B2) discloses a porous hollow fiber membrane in which the molecular chains have a degree of orientation (π) in the longitudinal direction, measured by wide-angle X-ray diffraction, and calculated as π = (180° − H)/180°. That is the same relationship used in the present specification ([0016]). Yasuda teaches a preferred range of 0.6 or more and less than 1.0, which overlaps the claimed 72% to 85%. Yasuda teaches a reason to use this range: when the orientation is 0.4 or more, the strength of the membrane increases. Yasuda is directed to a fluororesin hollow fiber (including vinylidene fluoride). The same X-ray method and formula were a standard way to report lengthwise orientation in fluororesin hollow fibers before the effective filing date. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to control the longitudinal orientation of the membrane (1) of MIYATA to a value in the claimed 72% to 85% range, as taught by Yasuda, with a reasonable expectation of higher mechanical strength. Lengthwise orientation is a known variable that affects strength, and picking an overlapping or optimized value is obvious. See MPEP 2144.05(II); In re Aller, 220 F.2d 454 (CCPA 1955).
Harada (US 5234751 A) shows that the endothermic peak recited in the claim is the melting peak of sintered PTFE, and that the peak is produced by heat treatment. After sintering, a lower endothermic peak appears at about 327 °C (327 ± 1 °C) on the DSC chart (C4/60-67). The reference calls that peak the melting point of the sintered product. That 327 ± 1 °C peak is inside the claim’s “vicinity of 328 °C” (323 °C to 333 °C; specification [0017]). The size of the heat of fusion at that peak tracks how crystalline the sintered PTFE is, which is set by the sintering or heat-treatment step. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to treat the 328 °C heat of fusion of MIYATA’s fired (365 °C) PTFE membrane (1) as a crystallinity value that can be adjusted, and to arrive at a value in the claimed 10.0–13.4 J/g range by routine testing as crystallinity affects pore size and strength.
Claim(s) 2-3 is/are rejected under 35 U.S.C. 103 as being unpatentable over MIYATA (WO 2020/059344 A1 citations from US 20220054987 A1) in view of HAYASHI (WO 2020/084930 A1 citations from US 20210379537 A1) and TANAKA (US 20170312694 A1).
Regarding claim 2, MIYATA states that the membrane may also have other layers besides the filtration layer ([0071]). TANAKA teaches a hollow fiber membrane (2) having a support layer (2a) and a filtration layer (2b) laminated on its surface, both mainly composed of PTFE (TANAKA, Hollow Fiber Membrane section; Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the PTFE membrane (1) of Doc 1 with a stacked PTFE support and filtration construction as taught by TANAKA because doing so improves mechanical strength and service life while keeping filtration performance (TANAKA, [0056]).
Regarding claim 3, TANAKA discloses a filtration module (1) comprising a plurality of hollow fiber membranes (2) held in one direction by a pair of holding members (upper holding member (3) and lower holding member (4)) (Filtration Module section). Each membrane (2) is a support-layer/filtration-layer stack.
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It is noted that any citations to specific, pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP 2123.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Waqaas Ali whose telephone number is (571) 270-0235. The examiner can normally be reached on M-F 9-5 PM.
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/WAQAAS ALI/Primary Examiner, Art Unit 1777
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