DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-5, in the reply filed on June 12th, 2026 is acknowledged.
Claims 6-10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected groups, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on June 12th, 2026.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-5 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 1, it is unclear if “50%” is the value of the filling rate as indicated by lines 3-4 or as an adjective describing the method of obtaining/measuring the filling rate as indicated by lines 16-20. If it is the former, then how can 50% be both? And if it is the latter, then what effect does the filling rate have on the structure/structural qualities of the carbon sheet.
Furthermore, the phrase “wherein, assuming that…” of lines 8-15 and the parenthetical phrase in lines 16-20 are confusing because it is unclear what is structurally part of the claim and what is hypothetical/intended/optional.
Even furthermore, it is unclear how a “filling rate” is calculated and what that entails structurally for the carbon sheet. The degree of orientation is also confusing, even in view of the definition set forth in the specification as the plane of reference for the degree/ratio is not clear.
Lastly, it is unclear how a (first surface side) region can comprise “consecutive layers” but the (second surface side) region may comprise only “a layer(s)” when the first surface side region is a smaller (less than or equal to 40 percent) portion of the thickness. when the layers “are divided….in the thickness direction”.
Multiple terms comprise antecedent basis issues (i.e. the degree of fiber orientation).
Regarding claim 2, the term “the fiber orientation angle” of the first and second surface sides does not have sufficient antecedent basis.
Regarding claim 3, this comprises many of these issues as lines 16-15 of claim 1.
Claims 4-5 are rejected for being dependent on rejected 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.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Ji et al. (U.S. Pub. No. 2007/0015042 A1) (hereinafter “Ji”), as evidenced by Froning et al. (Anisotropic properties of gas transport in non-woven gas diffusion layers…) (hereinafter “Froning”), Venu et al.(Structures and properties of hydroentangled nonwovens…) (hereinafter “Venu”), and Yang et al. (Effect of fiber curvature on gas diffusion layer…) (hereinafter “Yang”) OR in view of Sumioka et al. (U.S. Pub. No. 2013/0224625 A1) (hereinafter “Sumioka”), either as evidenced by or in view of Sode et al. (U.S. Pub. No. 2017/0244108 A1) (hereinafter “Sode”), and either (even further) in view of Kumaoka et al. (JP 2006-222024 A) (hereinafter “Kumaoka”).
Regarding claims 1-5, Ji teaches a diffusion medium carbon paper substrate comprising a wet-laid carbon stiff region/layer (All Figs. [12]) adjacent flow channels having a high rigidity/stiffness in the X-Y plane to prevent diffusion media from intruding into the flow channels [0026] and an air-laid or wet-laid carbon compressible region/layer (All Figs. [14]) having a relatively higher compressibility in the z-direction formed on each other in a papermaking process and bonded via a carbonizable binder [0027-0029], wherein the stiff layer has a thickness of at least 8% but no greater than 70% the total thickness of the gas diffusion medium, more preferably at least 15% and no more than 50% [0021], wherein an exemplary embodiment of the compressible region/layer is an airlaid hydro-entangled carbon paper such as or similar to Freudenberg’s H2315 [0022], wherein the paper has close to or substantially isotropic properties in the X-Y plane as evidenced by Froning that teaches in-plane permeabilities as being substantially equal in both direction despite possible appearances of directionality, which is further evidenced/corroborated by Venu that teaches regardless of the number of hydroentangling manifolds used, especially at lower numbers such as one (Fig. 15) instead of seven (Fig. 17), that an air-laid paper substrate will remain substantially isotropic (degree of fiber orientation of about 1) in the x-y plane throughout its thickness and at most will develop only some machine directionality (≤1.5 degree of fiber orientation) (Fig. 19). The compressible carbon paper region/layer comprising the airlaid hydro-entangled carbon paper such as or similar to Freudenberg’s H2315 would/should have a porosity (50% filling rate) having a porosity about or greater than 65% as evidenced by Yang (Fig. 3), which should correlate to a 50% filling rate as claimed (and within the claimed range), which would be different than the wet-laid paper porosity/50% filling rate.
The 50% filling rate of the wet-laid paper substrate should be set forth as claimed (and within the claimed range) due to the carbon fibers and papermaking method comprising a substantially similar structure and chemical composition as the claimed invention as evidenced as inherent or made obvious and motivated by Sode such that a higher filling rate leads to a desired increase a bending resistance of the stiffness layer [0052, 0054, 0058].
Alternatively, Sumioka teaches a wet-laid short fiber carbon paper comprising a region/layer that is not hydroentangled and a region/layer of wet-laid short fiber carbon paper that is hydroentangled, wherein one of ordinary skill in the art would have been motivated to provide the hydroentangled layer in a similar fashion to the air-laid hydroentangled layer, wherein both wet-laid processes would have lead to the 50% filling rate throughout the stiff region and relatively compressible region as set forth above.
However, the degree of fiber orientation of wet-laid carbon stiff region/layer for any of the above is not taught.
Kumaoka teaches a carbon fiber sheet for gas diffusion in a fuel cell comprising a carbon paper made via a wet-laid papermaking process [0014-0015, 0025, 0034, 0040] that degree of fiber orientation correlates directly to the number of fibers aligned with an orientation direction and a bending strength in that direction [0033], wherein the degree of orientation of the fiber is preferably 1.6 or higher, wherein balance between handling characteristics and orientation-imparted characteristics of high tensile strength and in-plane gas permeability is considered [0033], wherein the orientation direction is such that the fibers intersect the gas flow path/channels at an angle greater than 45°, preferably closer to 90° [0038].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the carbon paper stiff region/layer with an orientation degree within or obviously near the claimed range. One of ordinary skill in the art would have been motivated to orient the substantially x-y oriented fibers along one of the x-axis or y-axis such that they intersect the gas flow path channels, which increases reaction uniformity, reduces electrical resistance, and increases power generation [0018, 0038].
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (KR 2016-0120060 A) (hereinafter “KR Lee”), as evidenced by or in view of Sode et al. (U.S. Pub. No. 2017/0244108 A1) (hereinafter “Sode”); and optionally (further) in view of Scholz (DE 102018213155 A1) (hereinafter “Scholz”), Lee et al. (U.S. Pub. No. 2022/0200017 A1) (hereinafter “US Lee”), and Kumaoka et al. (JP 2006-222024 A) (hereinafter “Kumaoka”).
Regarding claims 1-5, KR Lee teaches a carbon substrate/sheet used as a gas diffusion layer of a fuel cell, wherein wet-laid papermaking techniques are used to form a substantially anisotropic (first side) surface of the carbon substrate adjacent the flow channels such that the fibers are oriented in a machine direction such that they are substantially perpendicular to the flow channels to prevent fiber intrusion thereinto over an isotropic fiber orientation (degree of fiber orientation of about 1) [0008-0011, 0040, 0074-0076, 0078-0080, 0083-0084, 0090, 0116, 0121-0122] that extends to a same, similar, or different (second side) surface having a degree of fiber orientation that is equally to less machine direction oriented anisotropic, isotropic, or cross direction oriented anisotropic [0058-0059, 0061] adjacent the microporous layer and polymer electrolyte membrane [0070, 0077, 0082], wherein the machine direction anisotropic portion having a degree of fiber orientation of from 1.2 to 4.0, preferably about 1.5 to 3.0 [0050, 0053, 0059-0060], wherein examples 1 and 2 comprise a machine direction anisotropic surface region with a fiber orientation degree of 2.5, wherein example 1 further comprises an intermediate region with a fiber orientation degree of 1.8 and a relatively isotropic surface region with a fiber orientation degree of 1.1 [0060, 0089-0090, Table 1] and example 2 further comprises relatively less machine direction anisotropic surface region with a fiber orientation degree of 1.5 [0077, 0101], wherein the machine direction anisotropic surface region extends 40 to 70% of the total thickness of the carbon substrate but is not limited to such [0024, 0050, 0060], wherein it is unclear if the gradient extends the entire thickness (i.e. the length of time the slit conditions held at each end of the papermaking process [0090, 0101]), such that it would have been obvious to one of ordinary skill in the art to lock conditions such that the variation/tolerance for the degree of fiber orientation were more uniform (~0 variation) along each of the formed regions such that any percentage of the total thickness less than 70% is prima facie obvious.
Further comprising claims 1 and 3, a porosity gradient may be formed such that the machine direction anisotropic surface region comprises a greater porosity (lower filling rate) than an opposing side surface region (higher filling rate) [0026, 0034-0035, 0054-0055, 0077, 0081-0082], wherein the 50% filling rate of the wet-laid paper substrate should be inherently set forth as claimed (and within the claimed range) due to the carbon fibers and papermaking method comprising a substantially similar structure and chemical composition as the claimed invention as evidenced as inherent or made obvious and motivated by Sode such that a higher filling rate leads to a desired increase a bending resistance of the stiffness layer [0052, 0054, 0058], wherein the porosity gradient the same/similar in the same direction for the same/similar reasons [0054].
In the event that the region having a degree of fiber orientation of 1.2 to 3.0 with a tolerance of ±0.10 is not taught as recited above:
Scholz teaches a gas diffusion layer comprising a support layer to prevent intrusion into flow channels, wherein a support layer (All Figs. [9]) having pores therein is formed from fibrous material whose fibers are oriented transversely to the channels and thus providing a higher stiffness in the required direction [0012, 0019].
US Lee teaches a carbon paper gas diffusion layer having a reinforcing portion (All Figs. [110]) formed by continuous fibers in a direction that crosses the flow channels at an angle from 45° to 90°, preferably orthogonally [0048, 0087], to prevent deformation bulges therein and to increase shear/tensile strength [0047, 0049-0050, 0053, 0088,0093], wherein the thickness of the reinforcing portion is 50% or less of the total thickness of the gas diffusion layer [0020, 0050], wherein Kumaoka teaches that materials with a higher degree of fiber orientation have a higher bending and tensile strength, the degree of fiber orientation being 1.6 or above, with some deference/consideration given to handling [0033], wherein an increased uniformity of fiber orientation would promote more uniform corresponding properties.
It would have been obvious to one of ordinary skill in the art at the time of invention to provide the machine direction-oriented surface region with or as a support/reinforcing region having a thickness within the range claimed and comprising more uniform properties equivalent to a reinforcing region formed by continuous carbon fibers. One of ordinary skill in the art would have been motivated to provide an equivalent structure with similar properties and a similar workable thickness range.
Conclusion
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to JEFFREY A VONCH whose telephone number is (571)270-1134. The Examiner can normally be reached M-F 9:30-6:00.
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If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, Frank J Vineis can be reached at (571)270-1547. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JEFFREY A VONCH/Primary Examiner, Art Unit 1781 September 10th, 2026
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