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 in response to applicant’s communication filed on 11/24/25.
Claims 1-24 are pending in this application.
Applicant's election with traverse of Group 1, claims 1-12, directed to a method of preparing an azo compound, in the reply filed on 11/24/25 is acknowledged. The examiner agrees with applicant’s suggested correction to the claim numbering.
Thus claims 13-24 are withdrawn from consideration being drawn to the non-elected invention.
As a result, claims 1-12 are being examined in this Office Action.
Priority
The applicant claims benefit as follows:
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Objections
Claim 4 is objected to because of the following informalities:
Claim 4 recites “contentcontent“. The examiner recommends instead “content“.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-12 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112, second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-7 are indefinite because of the recitation “Xb”, since applicant claims the definition of “a and b are independently any one integer from 1 to 4”. It is unclear how the “b” in this halogen molecule can be anything other than “2”. The Lewis Structure of a halogen molecule is typically diatomic. The examiner is unaware of any other molecule that contains only halogens that is chemically stable in solution, other than a dihalogen diatomic molecule. Applicant’s specification furthermore does not name or exemplify a single Xb molecule in which “b” is not 2.
Likewise, claims 1-7 are indefinite because of the recitation of MaXb, since the definitions of “a and b are independently any one integer from 1 to 4”. It is unclear how the “a” can be anything other than 1 for this molecular formula. Applicant’s specification furthermore does not name or exemplify a single MaXb molecule in which “a” is not 1.
Depending on applicant’s response, another 112 rejection might be in order. The dependent claims are rejected as being dependent on a rejected claim.
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 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 of this title, 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Prager et al. (US 3649484, pub date March 14, 1972), in view of Taniguchi et al. (WO 2012147953, pub date 01/11/2012, the English translation is used herein).
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
Prager et al. teaches an electrolytic process for forming azo compounds, specifically azodicarbonamide, by electrolyzing hydrazo compounds, specifically hydrazodicarbonamide (HDCA). HDCA is typically oxidized by chlorine or another compound which initiates and maintains the oxidation. In lieu of chemical oxidizing agents, electrolysis of alkali metal halides, such as sodium chloride or sodium bromide (which reads on applicant’s MaXb), is used to promote the oxidation. The hydrazo reactant is oxidized at the anode side to the azo product, while also forming sodium hydroxide and gaseous hydrogen, which are easily recovered. The azo product is isolated in high quality and yield. (column 2, line 25 to line 71)
The hydrazodicarbonamide (HDCA) structure is below:
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The azodicarbonamide product structure is below:
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The oxidation reaction is carried out in a typical electrolytic cell system. Even though the anode and cathode compartments are preferably separated by a semi-permeable membrane, Prager et al. does not teach separation of the compartments is required. A stirrer is used for uniform dispersion. (column 2, last line to column 3, line 5)
A typical procedure includes adding the electrolytic solution, then the hydrazo rectant to the electrolytic cell, then turning on the electrodes. During the reaction, the azo product and acid are formed near the anode. Also caustic soda (aka NaOH) and gaseous hydrogen (H2) are byproducts formed near the cathode. The reaction temperature can be carried out between room temperature and 60 degree C. (column 3, first paragraph, lines 23-40)
Prager et al. exemplifies the use of a combination of NaBr, NaCl, HCl and/or NaOH as additional reagents in the electrolytic oxidation. In Example 4, Prager et al. exemplifies 200 grams of sodium chloride in 2000 ml of cold water into both half-cells. To the anode compartment was added 50 ml of concentrated HCL (36% to 37%) and 59 grams (0.5 mole) of HDCA with stirring, with a pH of about 1-2. The power was turned on to 10 amperes for 3 hours. The solution was filtered washed and dried to give 72.3% yield of the azodicarbonamide product. In Example 1 and 3, 200 grams of NaBr in 2000 mls of water was used. In Example 2, 200 grams of NaCl and 12 grams of NaBr in 2000 mls of water was used. In Example 4, 200 grams of NaCl in 2000 mls of water was used. Additionally, HCl was added to Example 3 and 4. (column 3 to 4, Examples)
The electrolytes used in the electrolytic redox reaction can be hydrochloric acid, hydrobromic acid, sodium chloride, sodium bromide, etc. (column 4, lines 40-50, also see examples)
Since Prager et al. teaches the use of hydrochloric acid as the electrolyte and formation of gaseous hydrogen at the cathode, this would constitute the reduction of protons (or hydronium ions in an aqueous solution) in the following reduction half reaction that occurs at the cathode:
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Thus it would be reasonable to expect that the corresponding oxidation half reaction that occurs at the anode would be the formation of gaseous chlorine from the chloride ion of the hydrochloric acid electrolyte reactant, as follows:
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As a result, the balanced overall redox reaction of hydrochloric acid to gaseous chlorine and hydrogen can be written as follows:
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Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.012)
Prager et al. is deficient in the sense that it does not teach the recycling or repeated cycling of the reaction solution, along with additional hydrazo reactant.
Taniguchi et al. teaches the electrolytic production of azodicarboxamide (aka azodicarbonamide) from urea by the electrolysis of salts, such as sodium chloride (NaCl) and sodium bromide (NaBr). The electrolytic reaction was stirred and the resulting heterogeneous reaction solution produced sediment that was filtered to produce the azodicarbonamide product. In Examples 1, two electrodes and a salt, e.g. sodium bromide, were immersed and electrolysis was performed. The chemical equations for the production of azo compound in the prior art, including the reaction intermediates are as follows (abstract, examples and paragraph 4):
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From the above reactions, the transformation of urea to the azo product (7), goes through the hydrazo intermediate (6). Thus it would be reasonable to expect that Taniguchi et al.’s electrolytic production of azodicarboxamide from urea, would also go through (produce in situ) the hydrazo intermediate (6), since stepwise oxidation of urea would initially produce the hydrazo intermediate, which would further oxidize to the azo product, as shown below:
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Furthermore, as shown below in the following balanced half reactions from paragraph 4, are the redox reactions of the electrolyte NaCl that forms diatomic chlorine (Cl2) and sodium hydroxide (NaOH).
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Thus it would be reasonable to expect that the electrolysis of NaCl would form chlorine gas and NaOH, since Taniguchi et al. teaches the use NaCl as the electrolyte and Prager et al. also teaches the formation of sodium hydroxide (NaOH) as a byproduct of the electrolysis of azodicarboxamide (aka azodicarbonamide). Similarly, it would be obvious to form bromine gas from the electrolysis of sodium bromide (NaBr), since the corresponding oxidized halogen product would be diatomic bromine. Thus it would be reasonable to expect that the bromine precursor would be NaBr and the chlorine precursor would be NaCl, both of which (NaBr and NaCl) are taught by both Prager et al. and Taniguchi et al.
Taniguchi et al. also teaches the recycling of the reaction solution by reusing the electrolytic filtrate solution again, along with adjusting the reactants in the recycled solution. Additionally, the molar equivalents of urea is 0.001 to 10 molar equivalents per hydrogen halide (paragraphs 83 and 257)
With regard to applicant’s separate steps and separate solutions as claimed in applicant’s claim 1, these appear to separate out the electrolysis steps, which can be summarized and exemplified as follows:
An initial first step of forming diatomic halogen (such as chlorine or bromine gas) from MaXb (such as NaCl or NaBr), then a second step of oxidizing the hydrazo reactant with the chlorine or bromine gas formed, which gives the azo product, NaCl and HCl, then a third step of separating the azo product from the filtrate solution of NaCl and HCl, and then a fourth step of recycling and reusing the filtrate containing excess NaCl and HCl, with additional hydrazo reactant added, to produce more azo product, while also limiting waste from discarding the filtrate solution that contains excess electrolytes, e.g. salts and acids.
Since the art already teaches all of applicant’s electrolytes, e.g. NaCl, NaBr, diatomic chlorine, HCl, etc., applicant’s electrolysis reaction to form the azo product from the hydrazo reactant and recycling of the reaction solution, applicant’s particular electrolysis steps and solutions are obvious, especially since in MPEP 2144.04 IV. C., the order of prior art process steps is prima facie obvious in the absence of new or unexpected results.
With regard to applicant’s claim 8 of maintaining uniform concentration of HX throughout the steps, it would be an obvious optimization steps, especially since both Prager et al. and Taniguchi et al. teach stirring of the electrolytic reaction solution for uniform dispersion, and in order to avoid localized concentration of byproducts which can lower the purity and yield of the azo product.
With regard to applicant’s claim 9 and 10, it would be reasonable to expect both the negative and positive electrodes would be immersed in the reaction solution which is acidic and is in contact with the hydrazo reactant and azo product, since Prager et al. teach both the cathode and anode are immersed in the reaction solution that reacts with the hydrazo reactant and forms the azo product (see figure), and that the pH of the reaction solution is acidic (pH = 1-2) in Examples 3 and 4.
With regard to applicant’s claim 12, it would be reasonable to expect the azo product would be present in a slurry state since Prager et al. teaches filtering the reaction solution to isolate the azo product and also Taniguchi et al. teaches the resulting heterogeneous reaction solution produced sediment that was filtered to produce the azodicarbonamide.
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
Therefore, it would be prima facie obvious to one of ordinary skill in the art at the time of the invention, to reuse the filtrate from the electrolysis reaction and add additional hydrazo reactant to the recycled electrolyte filtrate solution, since Taniguchi et al. teaches the recycling of the filtrate and adjustment of the reactants for reuse. Additionally, recycling and reusing the reaction solution is a common optimization tool for a chemist, and not a patentable modification, absent evidence to the contrary.
Since Prager et al. exemplifies in its examples that the hydrazo compound is the limiting reactant (0.5 moles of HDCA), it would be obvious to add additional hydrazo reactant to the reused filtrate solution during the recycling of the filtrate, and to adjust the reactant concentrations in order to optimize the yield of the azo product. Since the reaction solution contains an excess of the reactant electrolytes, such as NaCl, HCl, it would be obvious to reuse the filtrate that contains leftover electrolyte reactants, and to adjust the concentration of the limiting reactant, the hydrazo compound, by adding more of the hydrazo reactant.
Thus with regard to applicant's limitations regarding the reaction temperature and the wt% of the reactants, such as MaXb, it is the position of the examiner that one of ordinary skill in the art, at the time of the invention, would through routine and normal experimentation determine the optimization of these limitations, including the Relational Equations which are based on these, to provide the best effective variable depending on the result desired. Because the art teaches a range of reaction temperatures and varying the concentrations for the halide reactants, such as NaCl and NaBr, the examiner asserts that the reaction temperature and the wt% of the reactants, such as MaXb, are art recognized result-effective variables. Thus it would be obvious in the optimization process to optimize the reaction temperature and the wt% of the reactants, such as MaXb. The applicant does not show any unusual and/or unexpected results for the limitations stated. Note that the prior art provides the same effect desired by the Applicant, the formation of purified azo compounds in high yield.
Additionally, merely modifying process conditions such as temperature and concentration are not a patentable modification, absent a showing of criticality. In re Aller, 220 F.2d 454, 105 U.S.P.Q. 233 (C.C.P.A. 1955). Generally, differences in concentrations will not support the patentability of subject matter encompassed by the prior art. Such formulations are results-effective variables which can be optimized. In in re Boesch, 617 F.2d 272,276, 205 USPQ 215, 219 (CCPA 1980), it was held that "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." Further, in In re Alter, 220 F. 2d454, 456, 105 USPQ 233,235 (CCPA 1955) the courts maintained that: "Where the general condition of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation."
Conclusion
No claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jennifer Cho Sawyer whose telephone number is (571) 270 1690. The examiner can normally be reached on Monday-Friday 9 AM - 6 PM PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Renee Claytor can be reached on (571) 272-8394. The fax phone number for the organization where this application or proceeding is assigned is 571-274-1690.
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Jennifer Cho Sawyer
Patent Examiner
Art Unit: 1691
/RENEE CLAYTOR/Supervisory Patent Examiner, Art Unit 1691
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