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 .
Claim Status
The claim amendments and remarks filed on 05/11/2026 is acknowledged. Claims 18-20 are newly added.
Claims 1-20 are currently pending and under examination.
Priority
The instant application claims domestic benefit to U.S. provisional application no. 63,389,174
filed on 07/14/2022 and U.S. provisional application no. 63,415,457 filed on 10/12/2022. Applicant’s
claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) is acknowledged.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 05/13/2026 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Withdrawn Rejections
35 USC 103 rejection over Dubois et al. in view of Dong et al. for claims 16 and 17 are withdrawn in favor of the new 35 USC 102 rejection and 35 USC 103 rejections below.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim 16 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Dong et al. (NPL, published in 2017, PTO-892).
Dong et al. teaches zeotropic Organic Rankine Cycles (ORC) (the cycle using zeotropic mixtures as working fluid). The selection of working fluid is very important for an ORC (see Introduction section). The performance of four pure refrigerants and their zeotropic mixtures as working fluids for low grade ORC through pinch analysis method. Among them, the cycle with R245fa/R113 (0.32/0.68) shows an efficiency of 10.73%, compared with 9.10% for R245fa (representing a relative increase of 17.96%) (see Results and Discussion section and Table 3 shown below).
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Regarding instant claim 16, Dong et al. teaches a mixture of R245fa, corresponding to the instant HFC-245fa, and R113, corresponding to the instant CFC-113, in a mixture of 32 wt% and 68 wt% respectively is a zeotropic mixture, corresponding to the instant azeotrope-like composition.
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.
Claims 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Dong et al. (NPL, published in 2017, found in PTO-892) in view of Unilab et al. (NPL, published 12/24/2018, PTO-892).
The teachings of Dong et al. were discussed above.
The teachings of Dong et al. differ from that of the instantly claimed invention in that Dong et al. does not teach wherein the amounts of CFC-113 and HFC-245fa are about 3.5 wt% and 96.5 wt% respectively as required by instant claim 17.
Unilab et al. teaches refrigerant fluids can be one component pure fluid, such as R134a and R1234ze, or mixtures of two or more refrigerants, such as R507, R410A, R407C and R455A. By mixing appropriately selected fluids and introduced into the formulation in a suitable concentration, the researchers try to mitigate the penalizing characteristics of one of the refrigerants present in the mixture, such as, for example, flammability, toxicity, global warming potential, inadequate miscibility with the compressor lubricant, and at the same time preserve, within suitable limits of use, the characteristics that make these molecules suitable for use as working fluids in steam compression machines. The azeotropic composition is subject to variations as the pressure changes. However, within the usual pressure ranges within which the refrigeration cycles operate, a mixture of a suitable intermediate composition can be considered, with a good approximation, azeotropic both at the condenser and at the evaporator.
It would have been obvious to combine the teachings of Dong et al. with the teachings of Unilab et al. before the effective filing date of the claimed invention by optimizing the concentrations of HFC-245fa and CFC-113 to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art to optimize the concentrations of CFC-113 and HFC-245fa because finding a suitable concentration will mitigate the penalizing characteristics of one of the refrigerants present in the mixture. One of ordinary skill in the art would have a reasonable expectation of success because optimization of concentrations to afford azeotropic behavior is a part of routine optimization.
Modified Rejections Necessitated by the Amendments Filed on 05/11/2026
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.
Claims 1-8, 10-12, and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Peng et al. (WO2021080645 A1, published on 04/29/2021, found in PTO-892) in view of Knapp et al.
(WO2008024508 A1, published on 02/28/2008, found in PTO-892) in view of Dubois et al.
(WO2021043989 A1, published on 03/11/2021, found in PTO-892).
Peng et al. teaches HFO-1234ze compositions and processes for producing and using the compositions. The fluorocarbon industry has been working to find replacement refrigerants for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) (see lines 14-22 of page 1). In addition to ozone depleting concerns, global warming is another environmental concern in many of these applications. Thus, there is a need for compositions that meet both low ozone depletion standards as well as having low global warming potentials. Certain hydrofluoroolefin compositions are believed to meet both goals. Thus, there is also a need for economical manufacturing processes that provide these compositions (see lines 23-27 of page 1). The disclosure includes a method of producing a mixture of a fluoropropene of formula CF3CH=CHF and a fluoropropene of formula CF3CF=CH2, comprising contacting a mixture of 1,1,1,3,3-pentafluoropropane (HFC-245fa) and Z-1,3,3,3-tetrafluoropropene (HFO-1234ze(Z)) in the gas phase with a catalyst to form a mixture comprising HFO-1234ze(Z), E-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)), 2,3,3,3-tetrafluoropropene, and optionally unreacted HFC-245fa (see lines 26-30 of page 2 and lines 1-3 of page 3). In a certain embodiment, HFO-1234ze(E) and HFO-1234yf may be separated from the HFO-1234ze(Z), hydrogen fluoride, and any unreacted HFC-245fa, which are then recycled back to the reactor with additional HFC-245fa (see lines 21-22 of page 11). One embodiment of the invention relates to any combination of the foregoing wherein said hydrogen fluoride produced in the first step is separated and recovered (see lines 21-22 of page 5). Hydrogen fluoride may be removed by scrubbing, by passing the reactor effluent through a solution of aqueous caustic, or hydrogen fluoride may be removed by distillation (see lines 22-24 of page 11). One embodiment of the invention relates to any combination of the foregoing wherein the mixture includes 0.1 to 0.5 mol% 2,3,3,3-tetrafluoropropene (see lines 25-26 of page 5). In one embodiment, the reaction vessel can be held at a temperature of between 200 °C and 375 °C (see line 5 of page 11). The reaction pressure can be subatmospheric, atmospheric, or superatmospheric. In one embodiment, the reaction is conducted at a pressure of from 14 psig to about 100 psig (see lines 9-10 of page 11). In an example provided in the specification of Peng et al., the contact time of the reactants in the reactor was 45 seconds (see line 22 on page 18).
The teachings of Peng et al. differ from that of the instantly claimed invention in that Peng et al. does not teach a feed stream additionally comprising CFC-113, forming a first product stream additionally comprising CFC-113, distillation of the unreacted HFC-245fa and CFC-113 to produce an overhead recycle stream and a bottoms stream, the recycle stream comprising unreacted HFC-245fa and a first amount of CFC-113, and the bottoms stream comprising a second amount CFC-113 greater than the first amount. As recited in instant claim 2, Peng et al. does not teach wherein the distillation apparatus is conducted at a pressure above 17 psia. As recited in instant claim 12, Peng et al. does not teach wherein the distillation apparatus is operated at least one of the following conditions: (i) a temperature of about 10°C to 105°C and (ii) a pressure of about -15 to 150 psia.
Knapp et al teaches an azeotropic distillation for separating fluoroolefin from mixtures of HF and fluoroolefin may be carried out using an entrainer compound (see lines 9-11 of page 32). The chemical manufacture of fluoroolefins may produce mixtures of the desired fluoroolefins and hydrogen fluoride (HF). The separation of fluoroolefins and HF is not always easily accomplished. Existing methods of distillation and decantation are very often ineffective for separation of these compounds. Aqueous scrubbing may be effective, but requires the use of large amounts of scrubbing solutions and produces excessive waste as well as wet product that must then be dried. Therefore, there is a need for new methods of separating HF from fluoroolefins (see lines 15-22 of page 1). The term "entrainer" is used herein to describe any compound that would be effective in separation of fluoroolefins from mixtures comprising HF and fluoroolefin in an azeotropic distillation process. Included as useful entrainers are compounds that form azeotropes with one or more of the components of a mixture, including fluoroolefins, HF, and possible hydrofluorocarbons for which the boiling point of at least one of such azeotropes is lower than the boiling point of the fluoroolefin/HF azeotrope. Entrainers may be selected from the group consisting of hydrocarbons, chlorocarbons, chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, perfluorocarbons, fluoroethers, HFPO, SF6, chlorine, hexafluoroacetone, and mixtures thereof (see lines 27-32 of page 24 and lines 1-7 of page 25). Chlorofluorocarbon (CFC) entrainers comprise compounds with carbon, chlorine and fluorine. Representative CFCs include but are not limited to a Markush grouping which includes 1, 1,2-trichloro-1,2,2-trifluoroethane (CFC-113) (see lines 20-25 of page 25). The process for separating a fluoroolefin from a first composition comprising HF and fluoroolefin comprises contacting said first composition with an entrainer to form a second composition. The contacting may occur in a first distillation column, or the second composition may be formed by mixing the components prior to feeding to a distillation column in a premixing step (see lines 6-11 on page 33). In an embodiment is provided a process for separating HF from a mixture comprising HFC-1234ze, HF, and at least one of HFC-245fa or HFC-245eb. The process comprises:
a. adding an entrainer to the mixture comprising HFC-1234ze, HF, and at least one of HFC-245fa or HFC-245eb thus forming a second mixture;
b. distilling said second mixture in a first distillation step to form a first distillate composition comprising HF and entrainer and a first bottoms composition comprising HFC-1234ze and at least one
of HFC-245fa or HFC-245eb;
c. condensing said first distillate composition to form two liquid phases, being (i) an entrainer-rich phase and (ii) an HF-rich phase; and
d. recycling the entrainer-rich phase back to the first distillation step (see lines 19-32 of page 47). The operating variables for the first distillation column will depend strongly on the entrainer being used in the separation process. In general, the first distillation column may operate at pressures from about 14.7 psia (101 kPa) to about 500 psia (3448 kPa) with a top temperature of from about -50 ° C to about 100 ° C and a bottom temperature of from about -30 ° C to about 200 ° C.
Dubois et al. teaches Hydrofluorocarbons (HFCs) and in particular hydrofluoroolefins (HFOs), such as 2,3,3,3-tetrafluoro-propene (HF0-1234yf) are compounds known for their properties as refrigerants and heat transfer fluids, fire extinguishers, propellants, foaming agents, blowing agents, gaseous dielectrics, polymerization media or monomers, carrier fluids, abrasives, drying agents and power generation unit fluids. Most hydrofluoroolefin manufacturing processes involve a fluorination and/or dehydrohalogenation reaction. This type of reaction is carried out in the gas phase and generates impurities which must therefore be eliminated to obtain the desired compound in a degree of purity sufficient for the intended applications. It is desirable to produce hydrofluoroolefins with a low impurity content (see paragraphs 0005-0010). Dubois et al. teaches a method for purifying a composition comprising a hydrohalocarbon B, comprising the steps of:
i) supplying a composition Al comprising a hydrohalocarbon B and at least one impurity C different from said hydrohalocarbon B,
ii) compressing said composition Al, and optionally cooling it, so as to obtain said hydrohalocarbon B in liquid form to form a liquid stream A2 comprising said hydrohalocarbon B,
iii) distilling said stream A2 obtained in step ii) to form and recover a stream A3 comprising said hydrohalocarbon B, characterized in that step iii) is carried out in a pressure distillation device comprising one or more rotating packed bed(s) (see paragraph 0013).
Preferably, said composition A1 comprises a hydrohalocarbon B selected from group B1; and at least one impurity C selected from group C1 (See paragraph 0073). In another embodiment, said composition A1 comprises a hydrohalocarbide B selected from a Markush group consisting of 1,3,3,3-tetrafluoropropene and at least one impurity C selected from a Markush group consisting of 2,3,3,3-tetrafluoropropene (HFO-1234yf) (see paragraph 0076 and 0078). In particular, said A1 composition includes less than 78% in weight of said at least one impurity C on the basis of the total weight of said composition (see paragraph 0079). According to a preferred embodiment, said hydrohalocarbon B is selected from a Markush group B1 consisting of various hydrohalocarbons including 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1,3,3,3-tetrafluoropropene (HFO-1234ze) (see paragraphs 0018 and 0019). According to a preferred embodiment, said at least one impurity C is selected from group C1 consisting of a Markush group of hydrohalocarbons including trichlorotrifluoroethane (CFC-113), 1,1,1,3,3-pentafluoropropane (HFC-245fa), and 2,3,3,3-tetrafluoropropene (HFO-1234yf) (see paragraphs 0023, 0028, and 0035). Preferably in step ii), said composition A1 is compressed under a pressure of 2 to 200 absolute bars (29 to 2900 psi) (see paragraph 0081). The implementation of step iii) makes it possible to purify said stream A2 in order to obtain a stream A3 which comprises said hydrohalocarbon B and in which the content of said at least one impurity C is reduced compared to the content of said impurity in said stream A2. In particular, said A3 stream may be free of said at least one impurity C (see paragraph 0096). Preferably, the content of said at least one (of said) impurity(ies) C in said stream A3 is less than the content of said at least one (of said) impurity(ies) C in said stream A2. More specifically, said A3 stream is free from said at least one (of said) impurity(ies) C. The term "free" used here corresponds to a content of less than 0.5%, advantageously less than 0.1%, preferably less than 0.01%, more preferably less than 0.001 %, in particular less than 0.0001 % by weight on the basis of the total weight of said stream (see paragraph 101). After purification, the hydrohalocarbon B thus recovered can be used in the production process of other hydrofluorocarbon compounds or be used in applications such as blowing agents for the preparation of polyurethane or polystyrene foam, refrigerant compositions, heat transfer compositions. The said impurity(ies) recovered in the A4 stream can also be used in processes for preparing hydrofluorocarbon compounds or in refrigerant compositions or heat transfer compositions (see paragraph 0107). The implementation of step iii) also makes it possible to recover a stream A4 comprising at least some, preferably all, of said at least one impurity C present in said stream A2 (see paragraph 0088). In particular, said A4 stream comprises at least 98% by weight of said at least one impurity C (see paragraph 0106).
It would have been obvious to combine the teachings of Peng et al., Knapp et al., and Dubois et al. before the effective filing date of the claimed invention by producing HFO-1234ze(E), as taught by Peng et al., and further including CFC-113 with the compounds of the feed stream during the production of HFO-1234ze(E), as taught by Knapp et al., separating HFO-1234ze(E) from HFC-245fa and CFC-113 and distilling the mixture of HFC-245fa and CFC-113, as taught by Dubois et al., to arrive at the instantly claimed invention. It would have been prima facie obvious for one of ordinary skill in the art to combine the reaction process as taught by Peng et al. with the entrainer as taught by Knapp et al., and the distillation processes as taught by Dubois et al. to produce HFO-1234ze(E) with fewer impurities such as CFC-113 because, as taught by Dubois et al., it is desirable to produce hydrofluoroolefins with a low impurity content sufficient for intended applications. One of ordinary skill in the art would have a reasonable expectation of success because all references aim to optimize the process of producing hydrofluorocarbons.
Regarding instant claim 1, Peng et al. teaches contacting a mixture of 1,1,1,3,3-pentafluoropropane (HFC-245fa) and Z-1,3,3,3-tetrafluoropropene (HFO-1234ze(Z)) in the gas phase with a catalyst to form a mixture comprising HFO-1234ze(Z) and optionally unreacted HFC-245fa, corresponding to the instant feed stream and first product stream without CFC-113. Knapp et al. further teaches, as discussed above, to add CFC-113 as an entrainer to the mixture comprising HFC-1234ze, (HFO-1234ze), HF, and at least one of HFC-245fa or HFC-245eb which would suggest one of ordinary skill in the art to add CFC-113 to the feed stream, taught in Knapp et al. as a pre-mixing step, with the combination of Peng et al. and Knapp et al. corresponding to the instant reacting step. Dubois et al. teaches purifying a mixture of a hydrohalocarbon B with at least one impurity C by compressing the mixture and distilling it. When hydrohalocarbon B is selected as HFO-1234ze from a Markush group and impurities from group C are selected as CFC-113 and HFC-245fa from a Markush group, the distillation which separates HFO-1234ze(E) from CFC-113 and HFC-245fa, as taught by Dubois et al., corresponds to the instant step of separating the first product stream to form the second product stream. When hydrohalocarbon B is selected as HFC-245fa from a Markush group and impurity C is selected as CFC-113 from a Markush group, the distillation which corresponds to separated HFC-245fa and CFC-113, as taught by Dubois et al., corresponds to the instant step of distilling the third product stream. Lastly, Peng et al. teaches recycling unreacted HFC-245fa to the reactor, corresponding to the instant recycling step.
As required by instant claims 2 and 12 and taught by Dubois et al., the distillation process occurs at pressures from 2 to 200 absolute bars.
As required by instant claims 3 and 5 and taught by Dubois et al., the stream containing primarily HFC-245fa (the recycle stream) is also taught to have less than 0.5% of the CFC-113 impurity after distillation.
As required by instant claim 4 and taught by Dubois et al., the A1 composition comprising HFC-245fa and CFC-113 would include less than 78% by weight CFC-113 and would be distilled.
As required by instant claims 6 and 7 and taught by Knapp et al., the mixture comprising HFO-1234ze, HFC-245fa, CFC-113 additionally contains HF and is conveyed to a separation device (distillation or scrubbing solution) to remove HF.
As required by instant claim 8 and taught by Dubois et al., the first product stream containing HFO-1234ze and a light impurity such as HFO-1234yf would be distilled by selecting HFO-1234ze and HFO-1234yf as the components of composition A1 and distilling the composition.
As required by instant claim 10 and taught by Dubois et al., the purification would reduce the level of light impurities, such as HFO-1234yf, in the composition or product stream to less than 0.5%.
As required by instant claim 11 and taught by Peng et al., the reaction vessel can be held at a temperature of between 200 °C and 375 °C.
Regarding instant claim 18, Peng et al. teaches the reaction vessel can be held at a temperature of between 200°C and 425°C, a pressure of from 14 psig to about 100 psig, and a contact time of 45 seconds which corresponds to the instant limitation of the reactor operating at a temperature range of 205-370 °C, a pressure range of -15 to 100 psia, and a residence time of 1 to 100 seconds. The temperature range, as taught by Peng et al., overlaps with the claimed range of 205 °C to 370 °C and in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976) (see MPEP 2144.05). Dubois et al. teaches the distillation steps at a pressure of 29 to 2900 psi, corresponding to the instant distillation occurring above 17 psia. The distillation step, as taught by Dubois et al. and corresponding to distilling the third product stream, wherein CFC-113 is chosen as impurity C from a Markush group, is taught by Dubois et al. to contain less than 78% by weight of said at least one (of) impurity (s) C on the basis of the total weight of said composition, corresponding to the instant limitation of distilling the third product stream when CFC-113 is 1 wt% or greater based on total weight of the third product stream.
Regarding instant claim 19, Peng et al. further teaches fluoropropene compositions formed from the method of contacting a mixture of 1, 1, 1,3,3-pentafluoropropane and Z-,l,3,3,3-tetrafluoropropene in the gas phase with a catalyst (see Brief Description of the Invention section). The composition is shown to have 14 ppm of component 114, corresponding to the instant second product stream comprising CFC-114 in an amount of 1000 ppm or less (see Table A).
Regarding instant claim 20, the distillation which separates HFO-1234ze(E) from CFC-113 and HFC-245fa, as taught by Dubois et al., and corresponds to the instant step of separating the first product stream to form the second product stream would naturally flow into recovering HFO-1234ze(E) from the second product stream as required by instant claim 20.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Peng et al. (WO2021080645 A1, published on 04/29/2021, found in PTO-892) in view of Knapp et al. (WO2008024508 A1, published on 02/28/2008, found in PTO-892) in view of Dubois et al. (WO2021043989 A1, Published on 03/11/2021, found in PTO-892) as applied to claims 1-8 and 10-12 above, and further in view of Low et al. (WO2021043989 A1, published on 01/16/2013, found in PTO-892.
The combined teachings of Peng et al., Knapp et al., and Dubois et al. were discussed above.
The combined teachings of Peng et al., Knapp et al., and Dubois et al. differ from that of the instantly claimed invention in that the combined teachings of Peng et al., Knapp et al., and Dubois et al. do not teach wherein the separation device comprises at least one of a batch or continuous fractional distillation column, spinning band distillation equipment, a wiped film evaporator, and combinations of the foregoing.
Low et al. teaches processes for purifying tetrafluoropropene, particularly 1,3,3,3-tetrafluoropropene (HFO-1234ze) and 2,3,3,3-tetrafluoropropene (see lines 3-4 of page 1). (Hydro)fluoroalkenes are increasingly being considered as working fluids in applications such as refrigeration, heat pumping, foam blowing, fire extinguishers/retardants, propellants and solvency (e.g. plasma cleaning and etching). The processes used to make (hydro)fluoroalkenes can lead to the generation of toxic and/or otherwise undesirable by-products. The presence of small quantities of impurities may not be detrimental to the bulk physical properties of the (hydro)fluoroalkene product and for some applications their removal is unnecessary. However, some applications require very low levels of impurities and/or the presence (or absence) of certain physical properties (see lines 15-25 of Page 1). TFMA and R-1234 may be separated from a mixture comprising those components using techniques such as distillative separation, adsorption and/or membrane separation. The distillative separation of TFMA from R-1234, particularly R-1234ze, more particularly R-1234ze(E) may be performed at a range of pressures, e.g. from about 1 to about 20 bar. Continuous or semi-continuous fractional distillation of TFMA from R-1234ze(E) may be effective in allowing separation of TFMA from R-1234ze(E) (see lines 13-18 of Page 2).
It would have been obvious to combine the combined teachings of Peng et al., Knapp et al., and Dubois et al. with the teachings of Low et al. before the effective filing date of the claimed invention by using continuous fractional distillation as a separation technique for purification of a product stream in the production of HFO-1234ze(E). It would have been prima facie obvious for one of ordinary skill in the art to purify the HFO-1234ze(E) produced using continuous fractional distillation as a separation technique because, as taught by Low et al., some applications of hydrofluoroolefins require very low levels of impurities and/or the presence (or absence) of certain physical properties. One of ordinary skill in the art would have a reasonable expectation of success because all references aim towards the optimization of hydrofluoroolefin purification.
Claims 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Dubois et al. (WO2021043989 A1, published on 03/11/2021, found in PTO-892) in view of Knapp et al. (WO2008024508 A1, published on 02/28/2008, found in PTO-892).
The teachings of Dubois et al. were discussed above.
The teachings of Dubois et al. differ from that of the instantly claimed invention in that Dubois et al. does not teach the separation device comprises at least one of zeolites, liquid extractants, azeotropic distillation apparatuses, mineral oil, and combinations of the foregoing.
The teachings of Knapp et al. were discussed above.
It would have been obvious to combine Dubois et al. with Knapp et al. before the effective filing date of the claimed invention by using an azeotropic distillation apparatus to remove CFC-113 from an HFC-245fa feed stream. It would have been prima facie obvious for one of ordinary skill in the art to purify the hydrofluoroolefin produced by azeotropic distillation because it is desirable to produce hydrofluoroolefins with a low impurity content sufficient for intended applications as taught by Dubois et al. One of ordinary skill in the art would have a reasonable expectation of success because both references aim towards the optimization of hydrofluoroolefin purification.
Response to Arguments
Applicant’s arguments filed on 04/22/2026 have been fully considered, but were not persuasive.
In regard to process (1), applicant states that the combination of Peng et al., Knapp et al., Dubois et al., and Low et al. fail to disclose or suggest the critical features of the present invention, namely, the recognition and exploitation of the pressure-dependent azeotrope between CFC-113 and HFC-245fa and the process-level benefits obtained by operating above the azeotrope-breaking threshold.
The applicant’s argument has been fully considered, but is not found to be persuasive. Regarding applicant’s arguments that the cited references fail to disclose or suggest an azeotrope between CFC-113 and HFC-245fa, Knapp et al. teaches using CFC-113 as an entrainer for azeotropic distillation in a premixing step for a mixture of HF, HFO-1234ze(E), and HFC-245fa. This corresponds to utilizing an azeotrope comprising CFC-113 and HFC-245fa for purification in the process to make HFO-1234ze(E).
Regarding applicant’s arguments that the cited references fail to disclose or suggest the process-level benefits obtained by operating above the azeotrope-breaking threshold, the process-level benefits, namely the impurity management and recycle strategy as stated by the applicant, would be a characteristic that would naturally flow from following the steps as taught by the cited prior art. The fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985)(see MPEP 707.07(f)).
Applicant further states instant claim 1 is directed to a specific, stepwise process for producing HFO-1234ze(E) that is neither disclosed nor suggested by the cited prior art. The applicant states the process includes four steps, as recited in instant claim 1, and the precise integration of these steps, and particularly the impurity management and recycle strategy, are not taught, suggested, or motivated in the prior art. Applicant further states none of the cite references, nor any combination thereof, teach, suggest, or motivate the specific process integration recited in instant claim 1 and there is no teaching of (1) the use of CFC-113 as a feed and its management throughout the process, (2) the separation of a third product stream comprising unreacted HFC-245fa and CFC-113 from the product stream, (3) the distillation of that third product stream into an overhead recycle (with a first amount of CFC- 113) and a bottoms stream (with a greater amount of CFC-113), and (4) recycling the overhead back to the feed.
The applicant’s argument has been fully considered, but is not found to be persuasive. The examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007) (see MPEP 707.07). Peng et al. teaches a process for producing HFO-1234ze(E) by reacting HFC-245fa in the presence of a catalyst which is combined with adding CFC-113 in the feed stream as an entrainer, as taught by Knapp et al. to arrive at the instant reacting step. Dubois et al. teaches distillation which separates HFO-1234ze(E) from CFC-113 and HFC-245fa which corresponds to the instant separating step. Dubois further teaches distillation to separate HFC-245fa and CFC-113, corresponding to the instant distilling step. Lastly, Peng et al. teaches recycling HFC-245fa, corresponding to the instant recycling step. Therefore, all active steps are taught by the combination of Peng et al. in view of Knapp et al. and Dubois et al.
In regard to the arguments regarding Peng et al., applicant states Peng’s process does not contemplate the presence of CFC-113 and therefore, does not disclose the process or benefits of CFC-113 in the system.
In response to the arguments regarding Peng et al., the applicant’s argument has been fully considered, but is not found to be persuasive. The combined teachings of Peng et al., Knapp et al., and Dubois et al. teach the process to make HFO-1234ze(E) with the inclusion of CFC-113 as an entrainer. One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (see MPEP 2145(IV)).
In regard to the arguments regarding Knapp et al., applicant states Knapp’s process is fundamentally directed to a different separation problem from the instant invention and thus, the process flow and the technical objective are fundamentally different.
In response to the arguments regarding Knapp et al., the applicant’s argument has been fully considered, but is not found to be persuasive. While Peng et al. does not teach the use of an entrainer, based on the combined teachings of the prior art, after the steps of Peng et al. are carried out and combined with the secondary references to include the use of an entrainer, as taught by Knapp et al., which would then proceed through the distillation steps, as taught by Dubois et al., and would result in HFC-245fa and CFC-113 being recycled through to the beginning of the reaction to thereby meet the claim limitations of instant claim 1. Furthermore, instant claim 1 recites comprising language and therefore, the premixing step of adding an entrainer, as taught by Knapp et al., is not excluded from the process steps. One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (see MPEP 2145(IV)). Therefore, the argument is not found to be persuasive.
In regard to the arguments regarding Low et al. and Dong et al., applicant states Low et al. does not mention the claimed recycle or purge steps. The applicant further states Dong et al. only considers the mixture of R245fa and R113 as working fluids in organic Rankine cycles.
In response to the arguments regarding Low et al. and Dong et al., the applicant’s argument has been fully considered, but is not found to be persuasive. The combined teachings of Peng et al., Knapp et al., Dubois et al., and Low et al. teach the process to make HFO-1234ze(E) with the inclusion of a continuous batch distillation. One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (see MPEP 2145(IV)). Therefore, the argument is not found to be persuasive.
Applicant argues the art does not recognize that if CFC-113 is not managed, this will accumulate in the recycle stream, react with HF to form CFC-114, and contaminate the product.
In response to this argument, the applicant’s argument has been fully considered, but is not found to be persuasive. The fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985) (see MPEP 707.07(f)).
Applicant argues the references combined are unrelated, generic process parameters, and broad disclosures which amount to improper hindsight reasoning.
In response to this argument, the applicant’s argument has been fully considered, but is not found to be persuasive. It must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant’s disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971) (see MPEP 707.07(f)). In the instant case, combining the distillation, as taught by Dubois et al., in the method, as taught by Peng et al., would have been obvious because it is desirable to produce hydrofluoroolefins with a low impurity content sufficient for intended applications.
Furthermore, it is noted that applicant argues unexpected results of superior process control in the remarks filed on 05/11/2026.
Here, applicant provided data from an ebulliometer study that shows the existence of an azeotrope at about 3.5 wt% CFC-113 and 96.5 wt% HFC-245fa at 14.29 psia and shows that this azeotrope weakens and disappears above about 20.4 psia. Furthermore, applicant provided data of the material balance for each stream in the process both below and above 17 psia which shows a lower accumulation of CFC-113 and CFC-114 throughout the process.
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Regarding the results of the ebulliometer study, the closest prior art is Dong et al. which teaches Table 3 (shown below) including a zeotropic mixture, corresponding to the instant azeotrope-like mixture, of R245fa, corresponding to HFC-245fa, and R113, corresponding to CFC-113, in a mixture of 32 wt% CFC-113 and 68 wt% HFC-245fa. The data presented, specifically temperature gradient during evaporation and condensation, also known as temperature glide, is a primary indicator of a zeotropic mixture. This can be compared to the instant ebulliometer study which shows the existence of an azeotrope or azeotrope-like mixture based on a minimum boiling point found at specific weight percents. However, the data presented by Dong et al. also teaches the mixture as zeotropic and therefore, the results of the instant ebulliometer study do not appear to be unexpected.
Further regarding the results of the ebulliometer study, the process as recited in instant claim 1 does not include pressure and therefore, the study is not commensurate in scope with the instantly claimed invention. While the process as claimed in instant claim 2 includes pressures above 17 psia, the study is still not commensurate in scope due to the wide range of pressure as recited in instant claim 2. Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support” (see MPEP 716.02).
Regarding the results of the material balance for the method to produce HFO-1234ze(E), the closest prior art is Peng et al. which teaches Table A (shown below) including the components of the composition produced from the method as discussed above. Peng et al. teaches producing HFO-1234ze(E) in 99.98 wt % with 14 ppm CFC-114, corresponding to 0.0014 wt% CFC-114. Peng et al. does not teach the concentration of CFC-113 in the results. However, applicant states CFC-113 will react with HF to form CFC-114, which Peng et al. does discuss, and this will also accumulate in the process. The data of Table A can be compared to the instant Table 4 (shown below) which shows material balance for
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the streams of the instant method. The weight percent of the final product, HFO-1234ze(E), as well as the weight percent of the CFC-114, is comparable in both methods and thus, the results of the CFC-114 concentration do not appear to be unexpected.
While applicant has established the existence of a pressure-dependent azeotrope between HFC-245fa and CFC-113, the pressure-dependent azeotrope would naturally flow from the active method steps as discussed in the rejection above. Furthermore, the data provided by the applicant does not support a comparison of the process controls between the instant method and the method as made obvious above and thus the argument of superior process controls cannot rebut the rejection under 103.
In regard to the arguments for claims 13-17, applicant argues Dubois et al. does not disclose or suggest the azeotrope between CFC-113 and HFC-245fa or its pressure-dependence. Applicant further argues Knapp et al. contains no teachings on the azeotrope as well. Applicant further argues Dong et al. contains no teachings or suggestion relevant to chemical separation, azeotrope formation, or pressure-dependent behavior.
In response to this argument, the applicant’s argument has been fully considered, but is not found to be persuasive. The combined teachings of Dubois et al. and Knapp et al. teach a process to remove CFC-113 from the HFC-245fa feed stream in the production of HFO-1234ze(E) by using an azeotropic distillation apparatus, as taught by Knapp et al., in the method to purify HFC-245fa, as taught by Dubois et al., to remove CFC-113 from an HFC-245fa feed stream. One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (see MPEP 2145(IV)).
Conclusion
No claim is found allowable.
This action is made second non-final in view of the new grounds of rejection above not necessitated by applicant’s amendment.
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/KRISTEN W BRADY/Examiner, Art Unit 1692
/SCARLETT Y GOON/Supervisory Patent Examiner, Art Unit 1693
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