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 6/29/26.
Claims 1-24 are pending in this application. Claims 13-24 remain withdrawn from consideration as being drawn to the non-elected invention. The objection and 112 rejection are withdrawn in response to applicant’s claim amendment filed 6/29/26. The rejection of claims 1-12 under 35 U.S.C. 103 as being unpatentable over Prager et al. (US 3649484) in view of Taniguchi et al. (WO 2012147953) is withdrawn in view of the new grounds of rejection set forth below, which are based on references submitted by applicant in the information disclosure statement filed on 4/17/26. As a result, claims 1-12 are being examined in this Office Action.
Claim Rejections – 35 USC 102
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 –
(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.
Claims 1-7 and 9-12 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Su et al. (“Study on a New Process for AC Blowing Agent – III. Electrolytic Oxidation Method”, Journal of Fuzhou University, 1986, No. 4, pages 99-105, in applicant's IDS filed 4/17/26, the English translation is used herein, the page numbers cited are those of the English translation).
Su et al. teaches the preparation of azodicarbonamide (AC blowing agent) by the electrolytic oxidation of biurea (hydrazodicarbonamide or HDCA) in an acidic solution containing Cl- and Br- ions, with a yield of 93-98%, a purity of 99.6% and a current efficiency of 88-92%. The mother liquor can be recycled and essentially no waste liquid is produced. (abstract)
In a typical procedure, the electrolyte solution is placed in a beaker, the biurea is added, and the electrodes are placed in the same beaker with a distance of 1.0 cm between the two electrodes. The solution is stirred and the power is turned on. When the required electrolysis time is reached, the power is turned off, the beaker is taken out, and the electrolysis solution is suction filtered to separate the azodicarbonamide product, which is washed, dried and weighed. (page 2, first paragraph)
The electrolyte solution contains, for example, 20% NaCl, 7% NaBr and 3% HCl, and the reaction temperature is 291.3 K to 318.2 K (about 18°C to 45°C). (page 2, Experimental Method, Table 1)
Su et al. teaches that the following reactions occur in the electrolytic cell (page 5):
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Su et al. further teaches that Cl2, Br2 or their hydrolyzed oxides in the solution react with the biurea, and that the moles of Cl- and H+ consumed by reactions (1) and (3) are compensated by reaction (4). (page 5, last section to page 6, first paragraph)
Thus Su et al. teaches applicant's first step, since the first solution in the beaker contains the hydrazo compound (biurea) and MaXb (NaCl, NaBr and HCl, where a is 1 and b is 1, i.e. the valence of Na or H), and electrolysis of this solution produces the Xb molecule, Cl2 or Br2 (where b is 2), at the anode by reactions (1) and (2).
Su et al. teaches applicant's second step, since the generated Cl2 or Br2 oxidizes the hydrazo compound (biurea) to the azo compound (azodicarbonamide) by reaction (4), which also produces 2 H+ and 2 Cl-, i.e. HX (HCl). The resulting second solution therefore includes the azo compound, MaXb (NaCl, NaBr) and HX (HCl).
Su et al. teaches applicant's third step, since the beaker is taken out and the electrolysis solution is suction filtered to obtain the solid azodicarbonamide, which separates the filtrate (aka mother liquor) containing NaCl, NaBr and HCl. (page 2, first paragraph)
The concentrations of NaCl, NaBr and HCl in the recovered mother liquor were measured, e.g. 12.5% NaCl, 2.7% NaBr and 2.1% HCl after the second recycle. (page 5, Table 7)
Su et al. teaches applicant's fourth step and repeated cycle, since the filtrate obtained after the electrolytic preparation of AC was in each case used as the electrolyte for the next cycle, with biurea at a concentration of 10% in each cycle, and the mother liquor was continuously recycled four times with an AC yield of 97.5-98.6%, a purity of 99.4-99.9% and a current efficiency of 90.5-92.2%. (page 5, section 7 and Table 7; page 6, 3rd paragraph)
Su et al. also teaches that when necessary, the concentration of each ion in the electrolyte can be replenished and adjusted, and the electrolyte can continue to be used, and that the net result of the whole system is AC and hydrogen gas with essentially no waste liquid. (page 6, 3rd paragraph)
With regard to applicant's claim 2, Su et al. teaches NaCl at 20% (Table 1) and teaches NaCl in the range of 5-20% (page 5, last section), which falls within applicant's range of 1 wt% to 30 wt%.
With regard to applicant's claim 3, Su et al. teaches both NaCl (a Cl2 precursor) and NaBr (a Br2 precursor). (Table 1; page 5, reactions (1) and (2))
With regard to applicant's claims 4 and 5, Su et al. exemplifies 5% NaCl with 3% NaBr (Table 5, No. 1), and 15% NaCl with 5% NaBr (Table 5, No. 2). These values fall within applicant's ranges of 3 wt% to 15 wt% for the Cl2 precursor and 0.05 wt% to 5 wt% for the Br2 precursor.
Su et al. also exemplifies NaBr at 0.7%, 1.5% and 3%. (Table 4) Su et al.’s values of Table 5, Nos. 1 and 2 are within applicant's claimed ranges, and also when the weight of the biurea in the first solution is included (e.g. about 4-5 wt% NaCl and about 2.5-3 wt% NaBr for Table 5, No. 1).
With regard to applicant's claims 6 and 7, the value of √(α2/β), where α is the wt% of MaXb and β is the reaction temperature in °C, can be calculated from Su et al.'s examples. In Table 5, No. 1, the reaction temperature is 308.2 K (35.05°C), and α is 5 (NaCl only), 8 (NaCl + NaBr) or 11 (NaCl + NaBr + HCl, since applicant's M includes hydrogen), which gives √(α2/β) of about 0.84, 1.35 or 1.86, respectively. In Table 1, No. 4, the reaction temperature is 303.2 K (30.05°C), and α is 20, 27 or 30, which gives √(α2/β) of about 3.65, 4.93 or 5.47, respectively. All of these values fall within applicant's Relational Equation (1) (0.1 to 9.5) and Relational Equation (1-1) (0.33 to 6.35).
With regard to applicant's claims 9 and 10, Su et al. teaches that both electrodes are placed in the same beaker, 1.0 cm apart, in the stirred electrolyte solution containing the suspended biurea (page 100, first paragraph), and the solution contains HCl and is acidic (Table 1). Thus the positive and negative electrodes are immersed in the same acidic solution, and the negative electrode is necessarily in direct contact with the suspended hydrazo compound and azo compound, since no separator is present.
With regard to applicant's claim 11, Su et al. teaches that the hydrazo compound is biurea (hydrazodicarbonamide or HDCA) and the azo compound is azodicarbonamide (ADCA). (abstract; page 5, reaction (4))
With regard to applicant's claim 12, Su et al. teaches that both biurea and azodicarbonamide are insoluble in water and dilute acid, and that the suspended electrolyte becomes relatively viscous at high biurea concentrations (page 3, last paragraph to page 4, first paragraph), and that the solid product is separated by suction filtration (page 2, first paragraph). Thus the azo compound is present in a slurry state before separating the third solution.
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 Su et al. (“Study on a New Process for AC Blowing Agent – III. Electrolytic Oxidation Method”, Journal of Fuzhou University, 1986, No. 4, pages 99-105, in applicant's IDS filed 4/17/26, the English translation is used herein, the page numbers cited are those of the English translation), in view of Bray et al. (GB 1177177, pub date January 7, 1970).
Determination of the Scope and Content of the Prior Art
(MPEP §2141.01)
The teachings of Su et al. are included in the rejection above.
Bray et al. teaches a method of oxidizing hydrazo compounds of the formula X-NH-NH-Y to the corresponding azo compound, by electrolyzing a solution or suspension containing the hydrazo compound and an oxidizing agent, preferably a bromide. (page 1, lines 26-40)
Bray et al. is particularly concerned with the electrolysis of an aqueous suspension containing hydrazoformamide (aka hydrazodicarbonamide or HDCA) and chloride and bromide ions, whereby the hydrazoformamide is converted into azodicarbonamide that is completely free from unchanged hydrazoformamide. (page 2, lines 91-100)
The electrolysis is desirably conducted in the presence of a supplementary electrolyte, such as sodium chloride and/or the acid from which the salt is derived, such as hydrochloric acid. (page 2, lines 4-24)
The bromide ions may be derived from sodium bromide, potassium bromide, hydrobromic acid or bromine, and are suitably present at 0.5-20% of the number of gram molecules of the hydrazo compound. (page 2, lines 25-49)
The electrolysis may be conducted in an electrolytic cell in which the electrodes are immersed in the same electrolyte, namely the hydrazo compound solution or suspension. (page 2, lines 55-58)
The hydrazo compound suspension is preferably stirred during electrolysis, the electrolysis is preferably carried out at 25°C to 70°C, and the azo compound is preferably insoluble in the electrolyte. (page 2, lines 73-90)
In Example 2, a stirred suspension of 50 parts of hydrazoformamide in an aqueous solution containing 5 parts of sodium bromide and 50 parts of concentrated hydrochloric acid was electrolyzed to give a 96% yield of azodicarbonamide containing no unreacted hydrazoformamide. (page 2, line 125 to page 3, line 11)
Ascertainment of the Difference Between Scope the Prior Art and the Claims
(MPEP §2141.012)
Su et al. is deficient in the sense that it does not expressly teach that the concentration of HX is maintained uniformly from the starting time of the first step to the ending time of the third step, as required by applicant's claim 8.
Su et al. teaches that the Cl-, Br- and H+ concentrations decrease somewhat during electrolysis, since the current efficiency is about 90%. (page 6, first paragraph)
Additionally, to the extent that Su et al.'s percentages are not considered to be weight percentages, or its single beaker electrolysis is not considered to expressly teach both electrodes immersed in the same solution, Bray et al. is relied upon.
Finding of Prima Facie Obviousness Rationale and Motivation
(MPEP §2142-2143)
Therefore, with regard to applicant's claim 8, it would be prima facie obvious to one of ordinary skill in the art at the time of the invention, to maintain the concentration of HCl uniformly throughout the first to third steps, since Su et al. teaches that the Cl- and H+ consumed by the electrode reactions (1) and (3) are compensated by the HCl regenerated by reaction (4), and that the ion concentrations can be replenished and adjusted when necessary.
Su et al. also teaches that the HCl concentration is a result-effective variable, since a lower HCl concentration increases the ohmic potential drop of the solution and the cell voltage, and a 3% HCl concentration is selected as suitable. Thus one of ordinary skill in the art would be motivated to keep the HCl concentration at the selected value throughout the reaction, in order to keep the cell voltage and the electrical energy consumption stable. Also, both Su et al. and Bray et al. teach stirring the electrolytic reaction suspension, which provides a uniform concentration throughout the solution.
With regard to applicant's claims 9 and 10, it would be obvious to immerse both the positive and negative electrodes in the same acidic hydrazo compound suspension, since Bray et al. expressly teaches that the electrolysis of hydrazoformamide to azodicarbonamide may be conducted in an electrolytic cell in which the electrodes are immersed in the same electrolyte, namely the hydrazo compound solution or suspension (page 2, lines 55-58), and Su et al. places both electrodes in the same beaker. Both references are directed to the same electrolytic oxidation of hydrazodicarbonamide to azodicarbonamide in chloride and bromide electrolytes, and thus one of ordinary skill in the art would have a reasonable expectation of success.
Thus with regard to applicant's limitations regarding the reaction temperature and the wt% of the reactants, such as MaXb, including the Relational Equations which are based on these (claims 2 and 4-7), 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, to provide the best effective variable depending on the result desired. Because Su et al. teaches varying the reaction temperature, and the NaCl, NaBr and HCl concentrations, and reports their effect on the AC yield, purity and current efficiency (Tables 1 and 4-6), and Bray et al. teaches a preferred temperature of 25°C to 70°C and a bromide content of 0.5-20% of the hydrazo compound (page 2,, line 45), 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, with recycling of the reaction solution.
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.”
Therefore, claims 1-12 are obvious over Su et al. in view of Bray et al.
Response to Arguments
Applicant's arguments have been considered but are not persuasive for the following reaons:
With regard to the rejection under 35 U.S.C. 103 over Prager et al. in view of Taniguchi et al., applicant's arguments are moot, since the new grounds of rejection do not rely on these references. Therefore claims 1-12 remain rejected.
Conclusion
No claims are allowed.
Applicant's submission of an information disclosure statement under 37 CFR 1.97(c) with the fee set forth in 37 CFR 1.17(p) prompted the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 609.04(b). 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
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 C SAWYER/Examiner, Art Unit 1691
/RENEE CLAYTOR/Supervisory Patent Examiner, Art Unit 1691
