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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 10/15/2025 has been entered.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Response to Amendment
The amendment filed 10/15/2025 has been entered. Claims 1-5 and 7-15 remain pending in the application. Applicant’s amendments to the Claims have not addressed every objection, 112(a) and 112(b) rejection previously set forth in the Office Action mailed 07/15//2025. Examiner thanks Applicant for their explanations in the Remarks.
Note: Examiner recommends that if the October 2024 Manual and hyperlink included within the 10/15/2025 Remarks include relevant information, the document should to be submitted within an Information Disclosure Statement.
Response to Arguments
Applicant’s arguments, see Remarks, filed 10/15/2025, with respect to the rejection(s) of under 35 U.S.C. 112 have been fully considered but are not persuasive.
Applicant argues “In the present invention, the RO membrane element comprises a RO membrane, wherein the RO membrane has a pore diameter of 7.0 Å or less… The principle of reverse osmosis is discussed starting on p. 13 (of 211) of the FilmTecTM Manual… As a property of how the RO membrane element purifies when the fluid flows through therein… the claimed RO membrane element can remove urea at a rate of 75% or more under the following conditions: a recovery rate of 70%” (See Remarks p. 8).
In response, Examiner maintains there is no support within the original disclosure for the conditions of claim 1 to be met with any membrane element wherein the RO membrane has a pore diameter range of 5.1 Å< x ≤ 7.0 Å. The supplied Manual it is not part of the original disclosure and does not overcome the 112 (a) rejection regarding lack of support for conditional 75% or more urea removal at the above pore diameter ranges. There is positive support for all conditions met only with a pore diameter of 5.1 Å in Example 8 of the instant specification.
Examiner points to the Note at the end of the Response to Arguments of the previous Action with regards the original disclosure examples’ support of pore size relationship to urea removal rate:
The examples seem to indicate that limiting the pore size to ≤ 7 Angstroms is not the pivotal driver of the results of the membrane properties of Claim 1 when under the conditions of 2 MPa pressure, and with the same raw water concentrations.
MPEP 2144.05 (III)(A) states “Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies”.
If there is another structural or compositional difference in the elements or components of the invention that would distinguish criticality, Applicant is encouraged to explore those inventive concepts.
Applicant’s arguments, see Remarks, filed 10/15/2025, with respect to the rejection(s) of claim(s) under 35 U.S.C. 103 have been fully considered but are not persuasive.
Applicant argues “the POSA would understand what matters is the recovery rate when evaluating a membrane's performance… removal rate decreases as the recovery rate increases. Therefore, when the FILMTEC FT30 membrane of Dow (2017) is used and operated at a recovery rate of 70%, the person having ordinary skill in the art ("POSA") would understand that the urea removal rate will necessarily be less than 70%. ” (See Remarks p. 13-14).
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., evaluating a membrane’s performance) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Claim 1 recites “the reverse osmosis membrane element removes urea … under the following concentrations and operating conditions”. Multiple operational and systemic variables play a role in obtaining a desired recovery rate, and those optimization decisions impact RO membrane element’s removal differently. For example, the US Dept. of Energy (K. L McMordie Stoughton, X. Duan, and E.M. Wendel. Reverse Osmosis Optimization. U.S. Department of Energy Federal Energy Management Program. DOE/EE 0955 ▪ August 2013.) teaches such reverse osmosis principles of RO membrane elements, including the importance of flow configuration to the recovery rate:
“Flow configurations that utilize concentrate staging produce more highly purified permeate and increase the permeate recovery rate” (US Dept. of Energy p 18). Additionally, in Remarks, p 25, the graphical representation of the relationship between Recovery and (Salt) Rejection show a large segment where increased recovery did not necessarily decrease rejection.
Applicant’s further arguments, see Remarks, filed 10/15/2025, have been fully considered but are moot because the new ground of rejection does not rely on the combination of reasoning and teaching applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Interpretation
In regard to the conditional limitations relied upon to achieve a ≥ 75% urea removal rate, MPEP 2111.04 (II) states “The broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met.”
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-5 and 7-15 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 recites “water diffuses through a reverse osmosis membrane within the reverse osmosis membrane element, thereby separating the urea-containing aqueous solution… the reverse osmosis membrane has a pore diameter of 7.0 Å or less … the reverse osmosis membrane element removes urea at a rate of 75% or more under the following concentrations and operating conditions: when an aqueous solution having the urea concentration being 520 mg/L and a sodium chloride concentration of 200 mg/L is passed through the reverse osmosis membrane element at the operating pressure being 2.0 MPa to obtain a recovery rate of 70%”
There is no support in the original disclosure that the above combined concentrations and operating conditions result in the reverse osmosis membrane element removing urea at a rate of 75% when passed through any reverse osmosis membrane pore diameter larger than 5.1 Å pores:
Example 3 is the example of a membrane element with a pore diameter closest to 7.0 Å (6.8) but that does not remove urea at a rate of 75% or more (69%) under the required concentration and pressure conditions.
As for the recovery rate operation condition of Example 3, it is unclear whether the original disclosure shows the reverse osmosis membrane element operated at a recovery rate of 70% under the urea and sodium chloride concentrations stipulated in claim 1, given the recovery is calculated under varying concentration conditions* (See Table 1 below ) over the reverse osmosis process itself.
Furthermore, Example 3 seems to contradict that a pressure of 2.0 MPa applied to a membrane element with pores greater than 5.1 Å can obtain recovery rates of 70% ([0094] show 60% recovery by the membrane element having 6.8 Å pores).
While Example 3 shows a 6.8 Å pore membrane existing in a multi-step system that resulted in an 80% recovery rate overall, this still resulted in only 69% urea removal rate.
Examiner maintains that no examples or evidence positively support a 70% recovery rate demonstrating 75% urea removal rate for any pore size above 5.1 Å.
Table 1. Specification examples of membranes tested under claimed conditions*
Pore Size
Membrane Recovery Rate
Urea Removal Rate
Example 1
5.1 Å
60%*
82%
Example 3
6.8 Å
60%*
69%
Example 8
5.1 Å
70%
75%
Example 9
10 Å
70%
63%
60*: 60 % recovery obtained after passing raw water B (the claimed concentration conditions) through the first membrane element.
80% recovery obtained overall after passing the concentrate of the first RO membrane element through the second membrane element in the system. Concentrate [Urea] and [NaCl] may be altered from initial concentration conditions.
Claims 2-5 and 7-15 depend on claim 1 and are also rejected.
Claim 10 recites “according to claim 1, wherein the pore diameter of the reverse osmosis membrane is 5.0 Å to 7.0 Å”
There is no support in the original disclosure that the required concentrations and operating conditions result in removing urea at a rate of 75% when passed through any reverse osmosis membrane having pores smaller than or larger than 5.1 Å pores (See Table 1 Above).
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 and 7-15 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.
Claim 1 recites “the reverse osmosis membrane element removes urea at a rate of 75% or more under the following concentrations and operating conditions: when an aqueous solution having a urea concentration of 520 mg/L and a sodium chloride concentration of 200 mg/L is passed through the reverse osmosis membrane element at pressure of 2.0 MPa to obtain a recovery rate of 70%.”
It is unclear what happens to the system outside the listed concentrations and operating conditions.
It is not clear whether the claimed method requires a step of passing the solution through the membrane element or whether the claimed method requires merely that the membrane element would be capable of effecting the claimed recovery rate were such a solution passed through it at the recited operating conditions.
Examiner maintains that as per the June 1, 2025 Interview summary “Examiner raised the question as to whether the passive voice passage (When .... is passed through) related to:
a) a conditional state where a result will happen if this condition is met
b) An executed condition occurred resulting in the current state”
“removes urea…under …operating conditions…at the operating pressure being pressure being 2.0 MPa to obtain a recovery rate of 70%” does not positively recite the 70% recovery as an operating condition that enables the removal rate %. The wording is such that the recovery is a result to obtain from the condition of the operating pressure being 2.0 MPa. It is unclear whether the recovery has been obtained and furthermore is now impacting the removal rate.
If there is support for that in the original disclosure for a 75% or more removal of urea to be condition on 70% recovery rate among the other requirements (see 112 (a) section for pore size discussion), Examiner suggests wording the claim to positively recite the membrane element removes urea contingent on the recovery rate, the concentration conditions, the pressure condition, etc. For example, such language as “the pressure of 2.0MPa” and “at a recovery rate of 70%” more clearly intonate that this is a condition.
For the sake of compact prosecution, Examiner interprets this passage as it is currently
written, such that the recovery rate is an expected result to obtain “when an aqueous solution having the urea concentration being 520 mg/L and a sodium chloride concentration of 200 mg/L is passed through the reverse osmosis membrane element at the operating pressure being 2.0 MPa”
Claims 2-5 and 7-15 depend on claim 1 and are also rejected.
Claim 2 recites “a recovery rate of the permeate in the reverse osmosis process is 80% or more”.
It is unclear whether the permeate in the reverse osmosis process is the same as the permeate of claim 1.
In Claim 1 appears to be directed to permeate of the reverse osmosis membrane element specifically, not permeate in the process as a whole: “water diffuses through a reverse osmosis membrane within the reverse osmosis membrane element, thereby separating the urea-containing aqueous solution into a concentrate having a higher urea concentration and a permeate”
However, permeate in the reverse osmosis process may not be the same permeate from the reverse osmosis membrane element of claim 1.
If recovery rate in amended claim 1 is under the set operational conditions specifically for the use of the reverse osmosis membrane element to achieve urea removal while operating to obtain a recovery rate of 70%, it is unclear whether “a recovery rate of the permeate” of Claim 2 is related to conditions applied to the membrane element itself.
Given that “80% or more” does not appear to include the claim 1 operating condition “to obtain a recovery rate of 70%”, for the purpose of compact prosecution, Examiner interprets “a recovery rate…in the reverse osmosis process” to be pertaining to any recovery in the overall RO process and not limited to the permeate of claim 1.
Claim 15 recites “an average height of protrusions of the protruding portions of the separation functional layer is 100 nm to 1000 nm”
It is unclear that protrusions is positively recited.
It is unclear whether there are protrusion atop the protruding portions, or whether “height of protrusions” is describing the height of the protruding portions from a baseline of the separation functional layer.
For the sake of compact prosecution, Examiner interprets an average height of protrusions as an average height of the protruding portions.
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 (i.e., changing from AIA to pre-AIA ) 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 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.
Claims 1- 5 and 10-12, and 14-15 are rejected under 35 U.S.C. 103 as being obvious over WO2008/020801-A1, hereinafter Wallenas, as evidenced by US-20090050563-A1, hereinafter Ruehr, in view of US-20170368510-A1, hereinafter Tanaka et al., further in view of (Lenntech. Dow Water Solutions FILMTEC™ Membranes Product Information Catalog Technical Manual Excerpt, Oct 2017), hereinafter Dow, motivated by US-2012/0067822-A1, hereinafter Ujang, further suggested by (Osmonics. Osmonics Pure Water Handbook. 2nd Edition. Minnetonka, MN. 1991. Excerpt), hereinafter Osmonics.
Regarding Claims 1, 2, and 10, Wallenas teaches a dialysate regeneration method (“A method and a system for regenerating a body fluid, such as a peritoneal dialysis fluid”, Abstract) that reduces a urea concentration of a urea- containing aqueous solution (“The permeate fluid … comprises …urea…and passes … to … a reverse osmosis (RO) unit…separated by a reverse osmosis membrane 55 having very small pores and essentially only passing water ” p 6 line 28- p7 line 5), the method comprising a reverse osmosis process (“a reverse osmosis filter for concentrating the body fluid”, Abstract) by supplying the urea-containing aqueous solution to a reverse osmosis membrane element (“The permeate fluid … comprises …urea…and passes … to … a reverse osmosis (RO) unit…separated by a reverse osmosis membrane 55 …passing water ” p 6 line 28- p7 line 5), wherein water diffuses through a reverse osmosis membrane within the reverse osmosis membrane element (“a semi-permeable membrane via diffusion of ions and substances…the fluid comprises…urea”, p 4 line 34- p 5 line 7; “a reverse osmosis (RO) unit…separated by a reverse osmosis membrane 55 …passing water ” p 7 line 2- p7 line 5), thereby separating the urea-containing aqueous solution into a concentrate (“a reverse osmosis filter for concentrating the body fluid”, Abstract) having a higher urea concentration and a permeate having a lower urea concentration (“The retentate fluid of the RO filter … comprises urea …concentrated … 15:1. The permeate fluid of the RO filter, i.e. pure water”, p 7 lines 25-30), wherein the reverse osmosis process is operated at a pressure of 0.5 MPa or more and 2.0 MPa or less (“pressure required to be produced by pump 52 may be small, such as around 10 Bar”, p 7 lines 19-20, 10 Bar is equivalent to 1 MPa), wherein the urea concentration of the urea-containing aqueous solution is 0.5 g/L or more (“The following flow rates may be used … the urea concentration in blood is 40 mM, the excretion rate will be 864 mmole per day”, p 9 lines 3-35, 40mM = 1.1 g/L), the reverse osmosis membrane has a pore diameter in the range of 5.0 Å to 7.0 Å (a reverse osmosis membrane 55 having very small pores … only passing water ” p 6 line 28- p7 line 5, water diameter = 2.8 Å), as evidenced by Ruehr’s discussion of what it means for a reverse osmosis membrane to essentially pass only water (“Reverse osmosis is in the final category of membrane filtration, "Hyperfiltration," and removes particles larger than 1 angstrom. Reverse osmosis membranes essentially retain the salts and organic compounds and essentially pass only water and molecules in the range of 5 Angstroms. Since essentially all dissolved and suspended material is rejected by the membrane, the RO permeate is essentially pure water”, [0038-0039]), wherein the reverse osmosis membrane element removes urea at a rate of 75% or more at a pressure to obtain a recovery rate of at least 70% (“The pressures will adjust themselves so that the flow rates are obtained”, p 13 ln 14-15; “The flow rate into the RO filter will be 920 ml/hour…The flow rate in line 71 to the ultrafilter will be 860 ml/hour”, p. 9 ln 12-15, meaning recovery rate (permeate flow/feed flow) would be 860/920 or 93%).
Wallenas provides motivation for optimizing operating conditions such as the pressure applied to obtain recovery, which impact the concentrations of retentate and by extension permeate: “the permeate fluid from nanofilter 40 lacks the ions separated by the electro-filter, which means that the osmotic pressure over the reverse osmotic membrane 15 will not be excessively high. The osmotic pressure is negatively proportional to the size of the substances. Since the smallest substances, such as sodium and potassium, are removed in the electrofilter 30, the pressure required to be produced by pump 52 may be small, such as around 10 Bar. The pressure and flow rate are controlled so that a desired concentration of the retentate fluid present in the first compartment 53 is obtained” (p. 7 ln 12-22, where 10 bar = 1MPa, and the pressure is controlled and regulated to achieve the design needs of the desired retentate concentration).
Wallenas is silent on the chemical composition of the reverse osmosis membrane and does not positively recite a combination of specific salt, urea, pressure, and recovery operating conditions required for removing urea at a rate of 75% or more.
However, Tanaka teaches a membrane comprises: a substrate; a support layer located on the substrate; and a separation functional layer that is provided on the support layer and comprises at least one of polyamide and cellulose acetate (“The polyamide, which serves as the framework of the separation functional layer is formed… on a surface of a supporting membrane (in the case of a supporting membrane including a substrate and a porous supporting layer, the interfacial polycondensation is performed on the surface of the porous supporting layer)”, [0082]).
Tanaka also teaches composite RO membranes are known and also teaches motivation for why polyamide in particular is extensively used (“Most of the reverse osmosis membranes… that are commercially available at present are composite semipermeable membranes…composite semipermeable membranes …obtained by coating a surface of microporous supporting membrane a with a separation functional layer including a crosslinked polyamide obtained by the polycondensation reaction of a polyfunctional amine with a polyfunctional acid halide are in extensive use as separation membranes having high permeability and selectively separating properties”. [0003]).
An embodiment of Tanaka further teaches a pore size overlapping 7 Angstroms or less (“the size of the fine pores as measured in the surface on the side where the separation functional layer is to be formed is 0.1 nm to 100 nm”, [0037], 0.1 nm = 1 Angstrom).
An embodiment of Tanaka provides motivation for operating conditions (Example 7) removing a target at a rate of 75% or more (Table 3: 98.7%) under the conditions of an aqueous solution with a sodium chloride concentration of at least 200 mg/L (“2,000 mg/L aqueous NaCl solution”, [0120]) passed through the membrane approaching operating pressure being 2.0 MPa (1.55 MPa [0120]).
Tanaka does not teach the target removed is urea.
However, Dow teaches a reverse osmosis membrane (“FILMTEC Membranes Basics of RO and NF: Membrane Description”, p 2 ¶1) comprises: a substrate; a support layer located on the substrate; and a separation functional layer that is provided on the support layer and comprises at least one of polyamide and cellulose acetate (“The FILMTEC TM membrane is a thin film composite membrane consisting of three layers: a polyester support web, a microporous polysulfone interlayer, and an ultra thin polyamide barrier layer on the top surface. Each layer is tailored to specific requirements”, p 2 ¶1).
Dow also provides motivation for the use of thin film composite polyamide reverse osmosis membranes for urea removal for relevant concentration ranges, given the Dow reverse osmosis membrane removes urea at a rate approaching 75% (“Urea, Rejection % - 70”, p 12; MPEP 2144.05 (III)(A) states “Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies”) under the following positively recited concentrations and operating conditions: when an aqueous solution having the urea concentration 0.5 g/L or more (“Solute rejection (approximate) 2000 ppm solute”, p 4) is passed through the reverse osmosis membrane element at the operating pressure approaching 2.0 MPa (1.6 MPa, p 4). Dow at least shows that A) polyamide is a fairly common polymer for reverse osmosis membranes, and B) reverse osmosis membranes made from this material can be impactful at urea removal at concentration levels that indicate the Dow membrane may be useful in multiple fields of application, such as biomedical or water treatment uses.
MPEP 2144.05 (II)(B) states “When there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense. In that instance the fact that a combination was obvious to try might show that it was obvious under §103”
Ujang further motivates the combination by teaching “the present invention has described the reverse osmosis aromatic polyamide membrane shall provide a high sodium chloride rejection to at least 98% when tested with 500 mg/L sodium chloride at pressure 552 kPa… the membrane shall have a molecular weight cut-off of above 100 and reject particles with size of less than 2 nm. As claimed in the present invention, the aromatic poly amide membrane shall contain size pores of less than 2 nm” ([0022-0023]), suggesting polyamide membranes with aromatic groups, like Dow, are capable of having pore size and withstanding testing condition parameters similar to Wallenas.
MPEP 2144.05 (II)(A) states “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation."”
Osmonics further suggests that regardless of membrane material, the scope of the reverse membrane process as a whole is defined by a size range of as least < 15 Angstroms.
MPEP 2112.01 (I) states “When the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent”.
MPEP 2144.05 (III)(A) states “Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies”
Wallenas is considered analogous art because Wallenas addresses the same problem of dialysate regeneration and the concentration of urea using RO membranes while obtaining high recovery..
Tanaka et al is considered analogous art because Tanaka et al addresses the same problem of optimizing a composite semipermeable membrane for removal rates under pressure and high saline conditions.
Dow is considered analogous art because Dow addresses the same problem of polyamide composite membranes tested under pressure, urea, and saline conditions.
Ujang is considered analogous art because Ujang addresses the same problem of polyamide composite RO membranes with small pore sizes.
Osmonics is considered analogous art because Osmonics addresses the properties of reverse osmosis membranes.
It would have been obvious to one of ordinary skill in the art, before the effectively filed date, to to utilize, within the high-recovery Wallenas system, the sub-nanometer pore polyamide membrane embodied in Tanaka tested with Tanaka operating conditions to enable target removals akin to Tanaka, further motivated and supported by Dow’s similar composite polyamide membrane testing conditions specifically with respect to targeted urea concentrations of Dow, with those polyamide membrane properties further suggested by Ujang.
It would have also been obvious to one of ordinary skill in the art, before the effectively filed date, to test and optimize the limits of the Wallenas RO process under concentration and operating conditions similar to the desired application or environment. Doing so would ensure effective reverse osmosis removal of target substances under pressures and target concentrations tolerable by physical properties of the Tanaka membrane which are defined, taught and/or at least suggested by Ruehr, Ujang, and Osmonics, respectively.
Regarding Claim 2, Wallenas teaches a recovery rate of the permeate in the reverse osmosis process is 80% or more (“The flow rate into the RO filter will be 920 ml/hour…The flow rate in line 71 to the ultrafilter will be 860 ml/hour”, p. 9 ln 12-15, meaning recovery rate (permeate flow/feed flow) would be 860/920 or 93%).
Regarding Claim 3, Wallenas teaches the reverse osmosis membrane element comprises a first reverse osmosis membrane element (“a reverse osmosis (RO) unit…separated by a reverse osmosis membrane” p 7 lines 3-5), and the reverse osmosis process comprises: a first step of obtaining, from the urea-containing aqueous solution, a first concentrate having a urea concentration higher than the urea concentration of the urea-containing aqueous solution and a first permeate having a urea concentration lower than the urea concentration of the urea-containing aqueous solution by the first reverse osmosis membrane element (“The retentate fluid of the RO filter … comprises urea …concentrated … 15:1. The permeate fluid of the RO filter, i.e. pure water”, p 7 lines 25-31).
Wallenas does not teach second reverse osmosis membrane element.
However, MPEP 2144.04 (VI)(B) states that mere duplication of parts has no patentable significance unless a new and unexpected result is produced.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to duplicate RO treatments for predictably higher urea concentration in the final concentrate and lower urea concentration in the final permeate.
Regarding Claim 4, Wallenas teaches the reverse osmosis membrane element comprises a first reverse osmosis membrane element (“a reverse osmosis (RO) unit…separated by a reverse osmosis membrane 55” p 7 lines 3-5), and the reverse osmosis process comprises: a first step of obtaining, from the urea-containing aqueous solution, a first concentrate having a urea concentration higher than the urea concentration of the urea-containing aqueous solution and a first permeate having a urea concentration lower than the urea concentration of the urea-containing aqueous solution by the first reverse osmosis membrane element (“The retentate fluid of the RO filter … comprises urea …concentrated … 15:1. The permeate fluid of the RO filter, i.e. pure water”, p 7 lines 25-31); and a second step of supplying the first permeate to a second membrane element (“The permeate fluid of the RO filter, i.e. pure water, is lead from the second compartment 54 via permeate outlet 58 and line 71 to an inlet 72 of an ultrafilter 70…separated by a membrane”, p 7 lines 30-34).
Wallenas does not teach second reverse osmosis membrane element.
However, MPEP 2144.04 (VI)(B) states that mere duplication of parts has no patentable significance unless a new and unexpected result is produced.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to duplicate RO treatments for predictably higher urea concentration in the final concentrate and lower urea concentration in the final permeate being supplying to the next element in the system.
Regarding Claim 5, Wallenas teaches a pretreatment process of reducing a salt concentration of the urea-containing aqueous solution by ion exchange before the reverse osmosis process (“the fluid comprises …urea” p 5 lines 4-7; “The fluid entering … the electrofilter passes along two membranes, a cation exchange membrane .and an anion exchange membrane”, p5 lines 20-25; “the fluid in the first compartment 53 of the RO filter… lacks the ions separated by the electro-filter, which means that the osmotic pressure over the reverse osmotic membrane 15 will not be excessively high.”, p 7 lines 9-15).
Regarding Claim 11, modified Wallenas is silent on weight % composition of RO membranes.
However, Tanaka teaches the separation functional layer comprises 50% by weight or more of a crosslinked aromatic polyamide (“The separation functional layer includes an aromatic polyamide. The content of the aromatic polyamide in the separation functional layer is preferably 80% by weight or higher… may be constituted substantially of an aromatic polyamide only.”, [0047]; “The separation functional layer formed of the crosslinked aromatic polyamide”, [0072]).
It would have been obvious to one of ordinary skill in the art, before the effectively filed date, to use the polycondensation formation of Tanaka for the RO membrane polyamide layer of modified Wallenas. Doing so would predictably result in a crosslinked polyamide separation functional layer, as taught in Tanaka [0072], and “composite semipermeable membranes… with a separation functional layer including a crosslinked polyamide … are in extensive use as separation membranes having high permeability and selectively separating properties” (Tanaka [0003]).
Regarding Claim 12, Wallenas is silent on membrane synthesis.
However, Tanaka teaches the crosslinked fully aromatic polyamide is formed by interfacial polycondensation of a polyfunctional aromatic amine (“The polyamide which constitutes the separation functional layer is an aromatic polyamide that can be formed by interfacial polycondensation of a polyfunctional aromatic amine with a polyfunctional carboxylic acid derivative”, [0049]), wherein the polyfunctional aromatic amine is selected from the group consisting of m- phenylenediamine [0136], p-phenylenediamine, and 1,3,5-triaminobenzene.
An embodiment of Tanaka teaches the polyfunctional carboxylic acid derivative includes a polyfunctional aromatic acid halide, wherein the polyfunctional aromatic acid halide is polyfunctional aromatic acid chloride (“trimesoyl chloride (TMC)”, [0136]).
Tanaka also provides motivation for using the [0136] embodiment, because the Table 1 value = 1.4, which equates to an x + y sum of 0.7 :
[0111]: In cases when B/(A+C+D) is 1.3 or larger, the proportion of the content of the substituents and the content of the terminal groups to the content of amide groups is small. Because of this, the polyamide can be inhibited from increasing in hydrophobicity … satisfactory water permeability can be rendered possible.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to incorporate the membrane of Tanaka into the Wallenas system at amide/ amino /carboxy values, such as those Tanaka Comp Ex. 1 embodiment. By doing so “the polyamide can be inhibited from increasing in hydrophobicity … satisfactory water permeability can be rendered possible” (Tanaka [0111]).
Regarding Claim 14, Wallenas is silent on surface roughness.
However, Tanaka et al teaches the separation functional layer of the reverse osmosis membrane has recessed portions and protruding portions (“The separation functional layer formed of the crosslinked aromatic polyamide forms a protuberance structure made up of protrusions alternating with recesses”, [0072]), wherein the protruding portions have a height of 1/5 or more of a 10-point average surface roughness (“protrusions each having a height not less than one-fifth the ten-point average surface roughness”, [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to incorporate the membrane protrusions of Tanaka et al into the modified Wallenas system. “In cases when the median value of the heights of the protrusions is 50 nm or larger, a composite semipermeable membrane having sufficient water permeability can be easily obtained. In cases when the median value of the heights of the protrusions is 1,000 nm or less, the protrusions do not collapse even when the composite semipermeable membrane is used in a high pressure operation, and stable membrane performance can be obtained.” (Tanaka et al, [0073]).
Regarding Claim 15, Examiner interprets “average height of protrusions of the protruding portions” as “average height of the protruding portions”.
Wallenas is silent on surface roughness.
However, Tanaka et al teaches average height of the protruding portions of the separation functional layer is 100 nm to 1000 nm (“the median value of the heights of the protrusions of the separation functional layer is … preferably 70 nm or larger… more preferably 800 nm or less”, [0073]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to incorporate the membrane protrusions of Tanaka et al into the modified Wallenas system. “In cases when the median value of the heights of the protrusions is 50 nm or larger, a composite semipermeable membrane having sufficient water permeability can be easily obtained. In cases when the median value of the heights of the protrusions is 1,000 nm or less, the protrusions do not collapse even when the composite semipermeable membrane is used in a high pressure operation, and stable membrane performance can be obtained.” (Tanaka et al, [0073]).
Claim 7, 8, and 13 is rejected under 35 U.S.C. 103 as being obvious over Wallenas, as evidenced by Ruehr, in view of Tanaka, further in view of Dow, motivated by Ujang, further suggested by Osmonics, further suggested by (Waterprofessionals. Reverse Osmosis Membranes Explained. August 22, 2018.. Accessed July 9, 2025. https://web.archive.org/web/20180822045442/https://www.waterprofessionals.com/learning-center/reverse-osmosis-membranes-explained/), hereinafter WaterProfessionals.
Regarding Claim 7, modified Wallenas teaches the reverse osmosis membrane comprises the polyamide (Tanaka [0082]).
Wallenas is silent on number of RO membranes in the RO unit (RO filter 50).
MPEP 2144.04 (VI)(B) states “mere duplication of parts has no patentable significance unless a new and unexpected result is produced”.
However, WaterProfessionals further suggests “semi-permeable membranes used for the RO process are typically made of a thin polyamide layer (<200 nm) deposited on top of a polysulfone porous layer (about 50 microns) on top of a non-woven fabric support sheet. Pore size is about 0.0001 micron” (p. 2), wherein multiple RO membranes are expected (“These membranes, typically six at a time, are loaded into single housings”, p. 2).
WaterProfessionals is analogous because WaterProfessionals teaches the typical amount of RO membranes in an RO process.
It would have been obvious to one of ordinary skill in the art, before the effectively filed date, to utilize more than one membrane, including the typical amount of six at a time, suggested by WaterProfessionals, to facilitate further separation capabilities.
Regarding Claims 8 and 13, Wallenas is silent on a molar ratio of carboxy groups to amide groups nor amino groups to amide groups as measured by 13C solid NMR.
However, Tanaka teaches molar ratio of carboxy groups to amide groups and amino groups to amide groups as measured by 13C solid NMR (Table 1 {amide/(amino + carboxy groups + -NXY and -NXYZ groups)} = 1.4), specifically Tanaka Table 1 Comp. Ex. 1 teaches a sum of x and y groups included in the separation functional layer of the reverse osmosis membrane is in the range of 0.3 to 0.7, given the Table 1 value is the inversion of x + y, which rearranges to (1/1.4) = 0.7.
Tanaka also provides motivation for the 1/(x + y) values > 1.3, which equates to an x + y sum of ≤ 0.8 :
[0111]: In cases when B/(A+C+D) is 1.3 or larger, the proportion of the content of the substituents and the content of the terminal groups to the content of amide groups is small. Because of this, the polyamide can be inhibited from increasing in hydrophobicity … satisfactory water permeability can be rendered possible.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to incorporate the membrane of Tanaka into the Wallenas system at optimal x + y values, such as the Tanaka Comp Ex. 1 embodiment. By doing so “the polyamide can be inhibited from increasing in hydrophobicity … satisfactory water permeability can be rendered possible” (Tanaka [0111]).
Claims 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wallenas as evidenced by Ruehr, in view of Tanaka, further in view of Dow, motivated by Ujang, further suggested by Osmonics, further in view of US2015/0190759-A1, hereinafter Shimura et al.
Regarding Claim 9, Wallenas is silent on a reverse osmosis membrane characterized by using an electron microscope.
However, Tanaka et al teaches the separation functional layer of the reverse osmosis membrane has protrusions as folds (“The separation functional layer formed of the crosslinked aromatic polyamide forms a protuberance structure made up of protrusions alternating with recesses”, [0072]), and when 10 arbitrary cross sections ([0079]), with a length of 2.0 µm in a membrane surface direction (“a width of 2.0 µm along the direction of the average line of the roughness curve”, [0079]), are observed by using an electron microscope (“The median value of the heights of protrusions can be determined with a transmission electron microscope”, [0077]), the protrusions having a height of 1/5 or more of a 10-point average surface roughness (“protrusions each having a height not less than one-fifth the ten-point average surface roughness”, [0079]), and an average height of the protrusions is 100 nm or more (“the median value of the
heights of the protrusions of the separation functional layer is … preferably 70 nm or larger… more preferably 800 nm or less”, [0073], reasonably overlapping and encompassing the range of 100 nm or more) in each cross section ([0079]).
Tanaka et al does not positively teach an average number density of the protrusions of the separation functional layer.
However, Shimura et al. teaches an average number density of the protrusions of the separation functional layer is 10.0 / µm or more (“The average number density of projections of the separation functional layer is preferably 10.0 projections/µm or higher, more preferably 13.0 projections/µm or higher.”, [0039])
Shimura et al is analogous art because Shimura et al addresses the same problem of optimizing a composite semipermeable membrane by characterization of a separation functional layer with electron microscopy.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effectively filed date, to incorporate the membrane protrusions of Tanaka et al with the protrusion density of Shimura et al into the modified Wallenas system. “In cases when the median value of the heights of the protrusions is 50 nm or larger, a composite semipermeable membrane having sufficient water permeability can be easily obtained. In cases when the median value of the heights of the protrusions is 1,000 nm or less, the protrusions do not collapse even when the composite semipermeable membrane is used in a high pressure operation, and stable membrane performance can be obtained.” (Tanaka et al, [0073]). Furthermore, when the average number density thereof is 10.0 projections/µm or higher, a composite semipermeable membrane “has an increased surface area and sufficient water permeability is obtained”, (Shimura et al [0039]).
Conclusion
K. L McMordie Stoughton, X. Duan, and E.M. Wendel. Reverse Osmosis Optimization. U.S. Department of Energy Federal Energy Management Program. DOE/EE 0955 ▪ August 2013. Teaches RP principles and factors affecting recovery rates
Snowate. RO System Recovery Rate Calculation & Influencing Factors. https://www.snowate.com/knowledge-calculator/knowledge/ro-system-recovery-rate-analysis.html Teaches the correlation between flow configuration and recovery rate
US 20030094406 A1 teaches optimization for rejection and recovery.
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MARRIAH ELLINGTON
Examiner
Art Unit 1773
/RICHARD C GURTOWSKI/ Primary Examiner, Art Unit 1773 02/26/2026