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 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.
Claims 1–17 is/are rejected under 35 U.S.C. §103 as being unpatentable over WO 2015/189064 (hereafter WO’064) in view of Obrecht (US 4,764,308, hereafter US’308) and further in view of WO 2012/130803 (hereafter WO’803).
WO’064 discloses a process for producing phosgene by reacting carbon monoxide and chlorine in a reaction chamber. WO’064 teaches supplying CO to a reaction zone containing chlorine, reacting CO with Cl₂ to form phosgene, and removing the phosgene from the reaction chamber. WO’064 further discusses control of chlorine levels for safety and process efficiency. WO’064 expressly teaches that the reaction of carbon monoxide with chlorine to give phosgene is “rapid and nearly quantitative with respect to both reagents” (¶[0091]) and that the reaction is normally operated on a continuous basis with a high degree of automation (¶[0092]). WO’064 further teaches that carbon monoxide is used in a small excess to ensure that all the chlorine is reacted and chlorine-free phosgene is obtained (¶[0099]). In addition, WO’064 teaches carrying out the reaction at superatmospheric pressure, for example 2–3 bar, so that the phosgene can be condensed by means of cooling water (¶[0100]).
These teachings correspond to claim 1 steps (b), (c), and (d), which require bringing carbon monoxide into contact in a reaction chamber to convert carbon monoxide to a phosgene-containing product and optionally collecting and reacting the phosgene.
US’308 teaches that residual chlorine in phosgene product streams is undesirable and discloses operating with excess carbon monoxide to minimize free chlorine in the phosgene product (see col. 1–2 and col. 3–4). US’308 expressly recognizes chlorine suppression as a routine objective in phosgene manufacture.
It would have been obvious to operate the WO’064 process under excess CO conditions as taught by US’308 in order to obtain a phosgene-containing product comprising less than 5 wt.% Cl₂, as recited in claim 1, because minimizing residual chlorine is a recognized goal and excess CO is a known solution.
Claim 1 further requires that the reaction chamber comprises a component having at least one polychlorine anion-containing compound.
WO’803 discloses chloride-containing ionic liquids capable of forming polychloride species such as Cl₃⁻ and Cl₅⁻. WO’803 describes ionic liquid cations selected from ammonium, phosphonium, imidazolium, pyridinium, and guanidinium families and teaches chlorine binding and stabilization in ionic liquid media (see pp. 7–8 and related discussion).
WO’803 thus teaches polychlorine anion-containing ionic liquid systems useful for binding and stabilizing chlorine species in process equipment.
Phosgene manufacture is recognized as a hazardous process involving toxic chlorine and phosgene gases. The art, including WO’064 and US’308, teaches controlling chlorine concentration and minimizing residual chlorine for safety and product quality.
WO’803 teaches ionic liquid systems that bind and stabilize chlorine through formation of polychloride anions, thereby improving chlorine containment and handling.
It would have been obvious to one of ordinary skill in the art to substitute the conventional chlorine reaction environment of WO’064 with a known chlorine-binding ionic liquid system as taught by WO’803 in order to improve chlorine containment, enhance process safety, and stabilize reactive chlorine species during phosgene synthesis. The motivation arises from the recognized hazards of chlorine and the known benefits of chlorine-binding ionic systems.
Under KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a combination of familiar elements according to known methods is likely to be obvious when it yields predictable results. Here:
• WO’064 teaches phosgene synthesis from CO and Cl₂.
• US’308 teaches minimizing residual chlorine via excess CO.
• WO’803 teaches chlorine-binding ionic liquid systems forming polychloride anions.
Substituting a known chlorine-binding ionic liquid medium into a known phosgene synthesis process represents use of a known material for its established function in a closely related chemical process. The resulting improvement in chlorine management and safety would have been predictable to one of ordinary skill in the art.
Accordingly, the combination reflects no more than predictable use of prior art elements according to their established functions.
Claims 2–4 recite specific cation families (ammonium, phosphonium, imidazolium, pyridinium, guanidinium) and polychloride structures. WO’803 discloses these cation families and formation of polychloride anions, rendering these limitations obvious.
Claims 5–7 recite component percentages and molar ratios. Adjustment of reactant ratios and component concentrations constitutes routine process optimization within the skill of the art.
Claims 8–13 recite temperature (<500°C), pressure above atmospheric, gas-phase behavior, and removal of phosgene. WO’064 teaches conventional phosgene reactor conditions within these parameters and removal of phosgene from the reaction chamber.
Claims 14–17 recite the presence of an organic solvent and dissolution of phosgene. Use of organic solvents to dissolve phosgene and facilitate downstream handling was known in phosgene processing and represents an obvious design choice to improve safety and control.
For these reasons, claims 1–17 would have been obvious over WO’064 in view of US’308 and WO’803.
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 17-19 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 17–19 is/are rejected under 35 U.S.C. § 112(a) for lack of enablement, because the specification does not enable the full scope of the claimed invention without undue experimentation.
Claims 17–19 require, inter alia, that phosgene be collected or dissolved in a liquid composition containing at least one organic solvent, including embodiments in which phosgene dissolves in the solvent at 20 °C and 1013 mbar to a specified extent (e.g., at least 1 g/L), while also requiring particular solubility or insolubility behavior of ionic chlorine-containing compounds. The claims are not limited to specific solvents or to a defined class of solvents, but instead encompass any organic solvent satisfying the recited functional solubility requirements.
An analysis of the factors set forth in In re Wands, 858 F.2d 731 (Fed. Cir. 1988), demonstrates that undue experimentation would be required to practice the full scope of the claims:
1. Breadth of the claims
The claims broadly encompass any organic solvent capable of dissolving phosgene to the recited extent, without limitation to the specific solvents disclosed in the specification.
2. Nature of the invention
The invention involves phosgene, a highly toxic and reactive compound, and requires accurate determination of solubility behavior under defined temperature and pressure conditions.
3. State of the prior art
The prior art does not provide a comprehensive or predictive framework for determining phosgene solubility and selective ionic compound solubility across the full range of organic solvents encompassed by the claims.
4. Level of skill in the art
While a person of ordinary skill in the art may be capable of measuring phosgene solubility in individual solvents, identifying all solvents that meet the claimed functional requirements would require extensive empirical testing.
5. Amount of guidance in the specification
The specification provides examples of certain solvents, but does not provide sufficient guidance or selection criteria to enable a skilled artisan to predict which additional solvents within the full scope of the claims would satisfy the solubility limitations.
6. Presence or absence of working examples
The working examples are limited to a small number of specific solvents and do not represent the full breadth of organic solvents encompassed by the claims.
7. Quantity of experimentation required
Practicing the full scope of the claims would require substantial screening of candidate solvents, including repeated solubility testing involving phosgene, which constitutes undue experimentation.
Accordingly, the specification does not enable a person of ordinary skill in the art to practice the full scope of claims 17–19 without undue experimentation.
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, 13 and 16-18 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 that “the phosgene-containing product formed in step b), based on the total weight, comprises less than 5.0% by weight Cl₂.” The claim does not specify the basis upon which the chlorine content is determined. In particular, the claim does not clarify whether the chlorine content is measured in a gas phase, a liquid phase, a multiphase product, or after separation or collection of phosgene. Because the claim encompasses embodiments involving different phases and different collection modes, the scope of the chlorine content limitation cannot be determined with reasonable certainty.
Claim 13 recites that carbon monoxide is introduced such that “the internal pressure of the reaction chamber is higher than atmospheric pressure.” The claim does not define whether the pressure condition refers to a transient pressure, a steady-state pressure, or a peak pressure, nor does it specify when or where within the reaction chamber the pressure is measured. As written, the claim lacks objective boundaries for determining compliance with the recited pressure limitation.
These claims recite that the phosgene-containing product “passes into the gas phase and remains on said component in the reaction chamber” or equivalent language. The phrase “remains on said component” is a relative and functional expression that does not define the required spatial or temporal relationship between the gas-phase product and the component. It is unclear whether this language requires adsorption, continuous contact, proximity, or mere presence within the same reaction chamber. Accordingly, the metes and bounds of the claims are not reasonably certain.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEBORAH D CARR whose telephone number is (571)272-0637. The examiner can normally be reached Monday-Friday (10:30 am -6:30 pm).
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/DEBORAH D CARR/Primary Examiner, Art Unit 1691