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 responsive to Applicant's Remarks and Amendment after Non-Final Rejection, filed Oct. 21, 2025. As filed, Claims 14-26 are pending are pending of which claims 14-16 and 18 are amended. Claims 25, 26 are withdrawn from consideration.
A complete response to this Office Action should include cancellation of non-elected subject matter or other appropriate action.
During a telephone conversation with Applicant's Representative, the Examiner proposed amendments to incorporate limitations of claim 15 to claim 14 and to cancel product claims 25-26, it was noted that the Applicants prefer to receive a further written office action instead.
Response to Remarks
Applicant’s amendments have been fully considered and are entered. The status for each rejection and/or objection in the previous Office Action is set out below.
The rejection of claim 18 under 35 U.S.C. § 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph is withdrawn in view of claim amendments to remove parenthesis.
The rejection of claims 18, 18-24 under 35 U.S.C. § 103 over US 2004/0000473 A1, Jan. 2004, by Hofen is maintained. Applicant's arguments filed 10/21/2025 have been carefully considered but they are not persuasive.
Applicant's argue that ” Hofen does not separate 1-methoxypropan-2-ol from the stream S2 obtained in ( c) by distillation, so that a stream S3 comprising 2: 95 weight-% l-methoxypropan-2-ol and :S 0.5 weight-% of 2- methoxypropan-1-ol, based on the total weight of stream S3, and a stream S4 comprising 2: 95 weight-% 2-methoxypropan-1-ol based on the total weight of stream S4, are obtained.”
In response, it is noted that the prior art by Hofen teaches on [0023]-[0036]that the mixture comprising substantially 1-methoxy-2-propanol and 2-methoxy-1-propanol is separated by distillation and that the amount of 1-methoxy-2-propanol in the distillate is preferably at least 95 percent of the amount of the same in the aqueous composition fed to the distillation step. As discussed before and reiterated herein, the determination of the 2-methoxypropan-1-ol and water concentration in solutions separated upon purification as an art recognized result-effective variables, is subject to routine optimization in the course of modification of the process of the ‘473 publication.
Furthermore, pertaining to the concentration, pressure, temperature of a process, it is noted that generally, differences such parameters will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such parameter 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) See MPEP 2144.5.
Applicant's further argue that “The separation and purification of l-methoxypropan-2-ol and 2-methoxypropan-1-ol, selecting a higher operating pressure, specifically at or above 2 bar, offers substantial process and product advantages over traditional atmospheric or low-pressure operations.” and that “Experimental results demonstrate that distillation conducted at higher pressures, with integrated heat management and energy recovery, can achieve product purities exceeding 99.9%
and isolation yields above 99.8%. These high-performance outcomes are realized in conjunction with exceptionally low levels of key impurities, such as propylene glycol dimethyl ether (<0.01 %), marking a significant improvement over processes operated at lower pressures or without heat integration.” (Remarks page 7).
It is noted the process features of the distillation column D is operated at a pressure higher that 2 bar with integrated heat management and energy recovery are not recited in the rejected claims.
The Applicant has not shown evidence of substantially improved and unexpected results between the instantly claimed process and the process disclosed by the prior art.
Please note that if Applicant intends to rely on unexpected or unforeseen results, attention is invited to MPEP 716.02. Absent clear, convincing, side-by-side data demonstrating unobviousness vis-a-vis the prior art commensurate with the scope of protection sought and showing that the claimed process and process disclosed by prior art are distinct, the claims are considered prima facie obvious.
The rejection is still deemed proper and is thus maintained.
Claim Objections
Claims 18, 20, 22-24 are objected to because of the following informalities: the recitation ”weight-%” contains a superfluous punctuation.
Appropriate correction is required.
Allowable Subject Matter
Claims 15-17 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim Rejections - 35 USC § 103 (maintained).
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 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 14, 18-24 are rejected under 35 U.S.C. 103 as being unpatentable over US 2004/0000473 A1, Jan. 2004, by Hofen (“the ‘473 publication”; cited by Applicants in IDS).
Instant claims are drawn to a process for separating 1-methoxypropan-2-ol from an aqueous stream comprising 1-methoxypropan-2-ol and 2-methoxypropan-1-ol, by the steps of :
a) providing a stream comprising 1-methoxypropan-2-ol, 2-methoxypropan-1-ol and
water;
b) separating 1-methoxypropan-2-ol and 2-methoxypropan-1-ol from the stream provided in a) by distillation in a distillation column operated at a pressure of ≥2 bar;
c) azeotropic distillation of the stream obtained in (b) with an entrainer under azeotropic distillation conditions;
d) separating 1-methoxypropan-2-ol from the stream obtained in ( c) by distillation,
comprising subjecting the stream obtained in (c) to distillation conditions in a
distillation unit comprising a distillation column;
e) optionally distillative separation of the stream comprising water and the entrainer
obtained in (c) in a steam stripping column using steam as stripping agent.
The ‘473 publication discloses a process of separating 1-methoxy-2-propanol and 2-methoxy-1-propanol from aqueous compositions, comprising the steps of a) dewatering of the aqueous composition comprising 1-methoxy-2-propanol and 2-methoxy-1-propanol to a concentration of 1-methoxy-2-propanol and 2-methoxy-1-propanol of at least 90% by weight in total and b) isolation of l-methoxy-2-propanol, 2-methoxy-1-propanol or mixtures thereof by distillation (abstract; fig 1; [0008]-[0009]).
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The ’473 publication teaches on [0022] the aqueous composition is concentrated prior to the dewatering step a) by a pre-distillation to contain at least 10
percent by weight in total of l-methoxy-2-propanol and 2-methoxy-1-propanol. The distillate obtained by such a distillation preferably contains the methoxy propanol isomers in an amount of 10 to 50 percent by weight. The aqueous composition comprising the isomers of methoxy propanol fed to the dewatering step contains the isomers in an amount of at least 10 weight percent in total and less than 55 weight percent (which corresponds to steps a) and b) of instant process). The dewatering step could be performed by azeotropic distillation using an additive or by extractive distillation. The aqueous composition can be concentrated prior to the dewatering step by means of a pre-distillation to contain at least 10 percent by weight in total of 1-methoxy-2-propanol and 2-methoxy-1-propanol (also referred to as MOP isomers). The distillate obtained by such a distillation contains the MOP isomers in an amount of 0 to 50 percent by weight - which corresponds to step b) of instant process.
The '462 publication teach that any suitable distillation column can be utilized for the pre-distillation step. The distillation column used for the pre-distillation can, be run at any suitable pressure; (which corresponds to steps b)-c) of instant process). A pressure in the range of 0.5 to 5 bar is indicated as preferred embodiment (which overlaps with the pressure of ≥ 2 bar of instant process). Subsequent to dewatering step the mixture comprising substantially 1-methoxy-2-propanol and 2-methoxy-1-propanol is separated by means of distillation which corresponds to step d) of instant process). The amount of 1-methoxy-2-propanol in the distillate is preferably at least 95 percent and most preferably at least 97 percent of the amount of the same in the aqueous composition fed to the distillation step ([0023]-[0036]; Figures 1-6; examples; instant claims 14, 19, 21, 22).
Regarding instant claims 14, 20, 23 and 24, the ‘473 teaches on [0020] and [0025] that the impurities present in the initial stream containing 1-methoxypropan-2-ol and 2-methoxypropan-1-ol are reduced to 0-1% in the pre-distillation step and referring to Fig 7, the bottom product (7) essentially contains 2-methoxy-1-propanol; residual water and low boiling impurities are contained in the head product (15) see [0042]. Furthermore, the percentage of 2-methoxypropan-1-ol in the final product containing 99 weight % 1-methoxypropan-2-ol, the ‘462 publication teach on table 4 [0049] that the bottom product was a mixture of 1-methoxy-2-propanol and 2-methoxy-1-propanol with a very low content of water; other impurities could not be detected while on table 5, [0051]:
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Note the limitation “less than 0.01 weight-% of propylene glycol dimethyl ether” reads on zero- i.e. absence of the impurity.
The difference between the method for separating 1-methoxypropan-2-ol from an aqueous mixtures comprising 1-methoxypropan-2-ol and 2-methoxypropan-1-ol isomers disclosed by the prior art of the ‘473 publication and the instantly claimed method in that the prior art does not specify the percentage of 2-methoxypropan-1-ol in the stream separated by distillation or the concentration of water/ isomer impurities in the separated bottom/ top streams
Regarding the concentration of 95 weight-% 2- methoxypropan-1-ol based on the total weight of stream S4, the ‘473 publication specifically teaches separating the aqueous mixture 1-methoxypropan-2-ol and 2-methoxypropan-1-ol to obtain an end stream containing more than 99% 1-methoxypropan-2-ol, and teaches in description of process as depicted in Fig [0036] that stream (7) consist of essential 2-methoxypronol. As such, the separated stream during the distillations steps contain the 2-methoxypropan-1-ol and water stream depleted by isomers and impurities.
The determination of the 2-methoxypropan-1-ol and water concentration in solutions separated upon purification as an art recognized result-effective variables, is subject to routine optimization in the course of modification of the process of the ‘473 publication.
Furthermore, pertaining to the concentration, pressure, temperature of a process, it is noted that generally, differences such parameters will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such parameter 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) See MPEP 2144.5.
The instantly claimed process therefore corresponds to the combination of prior art elements according to known methods to yield predictable results. There would have been a reasonable expectation for success since each element retains its intended function in the combination.
Thus, the elements of claims were known before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains, and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions and the combination would have yielded nothing more than predictable results to one of ordinary skill in the art before the effective filing date of the claimed invention. Therefore, the claimed invention, as a whole, would have been obvious to one of ordinary skill in that art before the effective filing date of the claimed invention.
"Exemplary rationales that may support a conclusion of obviousness include: (A) Combining prior art elements according to known methods to yield predictable results ". See MPEP § 2143. There would have been a reasonable expectation for success since the processes of the reference all employ the same basic process chemistry.
Thus, the instantly claimed process would have been obvious to one of ordinary sill in the art.
Conclusion
Claims 14, 18-24 are rejected. Claims 15-17 are objected to. Claims 25-26 are withdrawn from further consideration.
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 extension fee 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 date of this final action.
Telephone Inquiry
Any inquiry concerning this communication or earlier communications from the
examiner should be directed to:
Ana Muresan
(571) 270-7587 (phone)
(571)270-8587 (fax)
Ana.Muresan@uspto.gov
The examiner can normally be reached Monday - Friday (9:00AM - 5:30PM).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Scarlett Goon can be reached at 571-270-5241. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ANA Z MURESAN/Primary Examiner, Art Unit 1692