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 .
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.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1 May 2026 has been entered.
Claim Status
Applicant’s amendments to claim 12, addition of claim 25, and the cancellation of claims 20 and 21 in the filings on 17 March 2026 and 1 May 2026 have been entered been considered for this Action. The rejections of claims 20 and 21 are moot and are withdrawn.
Claims 1-11 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 20 August 2025.
Claim Objections
Claim 25 is objected to because of the word “while” has multiple meanings and the claim is therefore unclear. It is recommended that the claim be amended to read: “...wherein the step of reaction is performed in at least one of the plurality of reaction vessels at the same time that [[while]] the step of pyrolyzing …”.
Appropriate correction is required.
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.
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 12-15, 18-19, and 22-25 are rejected under 35 U.S.C. 103 as being unpatentable over Agarwal et al. (US 2015/0004089 A1) in view of Doering et al. (US 2014/0072497 A1).
Regarding claim 12, Agarwal teaches a method for preparing trisilylamine (abstract) comprising the steps of introducing reactants into a reactor (providing a reaction mixture of trisilylamine and monochlorosilane into a reactor…contacting the reaction mixture with ammonia; [0012]); reacting the introduced reactants to produce trisilylamine and a reaction by-product (to provide a crude mixture comprising trisilylamine and an ammonium chloride solid; [0012]); discharging trisilylamine from the reactor (once the reaction is completed, crude TSA can be transferred from the reactor; [0027]); wherein, in the step of reacting, the temperature in the reactor is maintained at a temperature of about 25°C to about 30°C during the step of reacting (in certain embodiments the reaction occurs at room temperature, or about 25°C to about 30°C; [0020]), which is lower than the boiling point of trisilylamine is (52 °C).
Agarwal further teaches discharging the ammonium chloride by product from the system using a flow of nitrogen gas ([0031]), but does not teach pyrolyzing the byproduct in the reactor after discharging trisilylamine. Agarwal also does not teach the reactor comprising a plurality of reaction vessels that are connected in parallel to sources of reactants or the step of reacting being performed simultaneously of alternately in the plurality of reaction vessels.
However, Doering teaches that at temperatures higher than the decomposition temperature of the co-product (by-product) (the temperature of the gas mixture … is higher than the decomposition temperature of the coproduct of hydrogen halide and ammonia…in the range from 340 °C to 550 °C; [0008] and [0010]), hydrogen halide and ammonia can be removed from the reactor in the gas phase after the reaction (the product mixture is discharged as a gaseous mixture from the reactor. The gaseous product mixture typically contains trisilylamine, hydrogen halide and ammonia; [0008]). Doering further teaches that heating above the decomposition temperature of the co-products prevent solid ammonium halide formation ([0014]). One of ordinary skill in the art would recognize that Doering is describing that at temperatures in the range 340 °C to 550 °C ammonium halides, and ammonium chloride in particular, decompose (pyrolyze) to gaseous ammonia and hydrogen halides.
Doering also teaches that the reaction to generate ammonium halide precipitate can be conducted in plurality of reaction vessels which are connected in parallel and which can be operated simultaneously or alternately, and that such a configuration enables the precipitate to be removed from one vessel while the other continues to operate ([0034]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention add to the method of Agarwal the steps of pyrolyzing the reaction by-product (ammonium chloride) in the reactor after discharging trisilylamine and discharging the gaseous by-products produced in the step of pyrolyzing the reaction by-product (ammonia and hydrogen chloride) from the reactor, wherein the step of pyrolyzing the reaction by-product comprises a step of heating the reaction space of the reactor to a temperature of 340 °C to 550 °C, which is equal to or higher than the decomposition temperature of the reaction by-product. One of ordinary skill in the art would have been motivated to do so because Agarwal teaches that it is desirable to remove the accumulated solid ammonium chloride from the reactor after discharging the trisilylamine, and Doering teaches a method for removing ammonium chloride from the reactor involving the instantly claimed steps.
It would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the process of modified Agarwal in a reactor comprising a plurality of reaction vessels that are connected in parallel to sources of reactants, where the step of reacting is performed simultaneously of alternately in the plurality of reaction vessels, as taught by Doering. One of ordinary skill in the art would have been motivated to do so because such a configuration enables the product of one reaction to be removed from one vessel while the reaction continues in the other vessel, as taught by Doering.
Regarding claims 13 and 14, modified Agarwal teaches the method of claim 12, where Agarwal also teaches introducing an inert gas comprising nitrogen to assist in the carrying away of the ammonium chloride . Agarwal does not teach the inert gas being heated to a temperature equal to or higher than the decomposition temperature of the reaction by-product.
However, Doering teaches that it is preferable to heat the system containing the gaseous products and an inert gas, preferably nitrogen or argon ([0012]), to a temperature higher than the decomposition temperature of the byproduct (coproduct) in order to prevent solid ammonium chloride formation ([0014]).
Therefore, it would have been obvious to one of ordinary skill in the art to heat the inert gas comprising nitrogen taught by Agarwal to a temperature higher than the decomposition temperature of the reaction by-product. One of ordinary skill in the art would have been motivated to do so in order to prevent the ammonium chloride from re-precipitating as a solid, thereby inhibiting its gas phase discharge in the method of modified Agarwal.
Regarding claim 15, modified Agarwal teaches the method of claim 13, where Doering further teaches treating the gaseous by-products (precipitation of the co-product by cooling; [0018]).
Regarding claim 18, modified Agarwal teaches the method of claim 12, where Agarwal also teaches heating the reaction space of the reactor to a temperature of 50 °C to 100 °C ([0028]), which includes temperatures equal to and higher than the boiling point of trisilylamine.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed ranges merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding claim 19, modified Agarwal teaches the method of claim 12, where the step of reacting is performed in a batch manner (the reactions were conducted in a batch wise manner; [0037]).
Regarding claim 22, modified Agarwal teaches the method of claim 12, where Agarwal also teaches condensing and collecting gaseous trisilylamine (TSA can be collected in an optional condenser ([0027]).
Regarding claim 23, modified Agarwal teaches the method of claim 12, and Agarwal also teaches the discharging of a solid reaction by-product from the reactor (solid ammonium chloride remains in the reactor and can be removed safely from the reactor. Solid ammonium chloride contains sorbed TSA and polysilazanes; [0028]). The modifications taught by Doering teach an alternate method to remove the ammonium chloride, but do not teach removing polysilazanes, some of which can be solids ([0005]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to maintain in the method of Agarwal the step of discharging solids that are accumulated in the reactor and not pyrolyzed in the step of pyrolyzing. One of ordinary skill would have been motivated to do so in order to clean out the reactor of accumulated solids and enable its future use.
Regarding claim 24, modified Agarwal teaches the method of claim 12 where the reactants include monochlorosilane and ammonia, and the reaction byproduct includes ammonium chloride (a reaction mixture of trisilylamine and monochlorosilane …contacting the reaction mixture with ammonia to provide a crude mixture comprising … ammonium chloride solid; [0012] and Eq. 1).
Regarding claim 25, modified Agarwal teaches the method of claim 12, where Doering teaches that the reaction is carried out in a plurality of vessels where one reaction vessel can be operated while precipitate is removed from the other ([0034]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to perform Agarwal’s step of reacting in at least one of the plurality of reaction vessels while the step of pyrolyzing or the step of discharging is performed in at least one other reaction vessel. One of ordinary skill in the art would have been motivated to do so because the pyrolysis and discharging steps are used in the method of modified Agarwal to empty the reaction vessel, and Doering teaches that the generation of the precipitate and its removal can be operated simultaneously in different vessels.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Agarwal et al. (US 2015/0004089 A1) and Doering et al. (US 2014/0072497 A1), as applied to claim 15, and further in view of Wan et al. (US 2006/0199357 A1).
Regarding claim 16, modified Agarwal teaches the method of claim 15, but neither Agarwal or Doering teach removing gaseous by-products by a scrubber.
However, Wan teaches a process, which like that of modified Agarwal, has discharge streams that may include hydrogen chloride and/or ammonia (Fig. 2 and [0056]). Wan further teaches that unreacted process gases and gaseous reaction by-products from this process are exhausted to a scrubber to condense environmentally dangerous fumes before exhausting to the atmosphere ([0056]).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to include a scrubber in the method of Agarwal as taught by Wan. One of ordinary skill would have been motivated to do so in order to remove the environmentally dangerous gases of hydrogen chloride and ammonia generated by the process.
Response to Arguments
Applicant's arguments filed 1 May 2026 with respect to the rejection of claims 12-15 and 18-24 under 35 USC § 103 have been fully considered but they are not persuasive.
Applicant argues, pages 10-11, that the cited documents do not teach a method that utilizes a reactor comprising a plurality of reaction vessels that are connected in parallel to sources of reactants where the step of reacting is performed simultaneously of alternately in the plurality of the reaction vessels, as instantly claimed. However, this teaching is found with Doering ([0034]), rendering the amended claims obvious over the cited prior art, as analyzed above.
Applicant’s argument on page 11 with respect to rejection of claim 16 is also not persuasive, as it based upon the same assertion of deficiencies in Agarwal and Doering that were not found persuasive.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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