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
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:
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.
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 1-16 are rejected under 35 U.S.C. 103 as being unpatentable over Jin et al (Kr 101759512 B1 machine translation).
Applicants’ claimed invention is directed to a method for chlorinating an aromatic compound, the method comprising: in a plurality column-type reactors connected in series, introducing a reaction product produced in a former reactor to a latter reactor, introducing a chlorine gas to a low portion of each reactor in the same amount to perform a chlorination reaction in each reactor, and discharging a hydrogen chloride gas produced in each of the reactors from each reactor.
While Jin discloses (see abstract, Examples 2-4 and description of drawings) a method for chlorinating an aromatic compound and the use of internal stages, the specific structure and process configuration of the claim differs in the following ways:
Physical connectivity: the claim requires a plurality of reactors connected in series. Jin describes a single reactor (100) containing 5 internal stages (reaction unit 30).
Inter-Reactor transfer: the claim involves introducing a reaction product from a former reactor to a later reactor. Jin involves internal liquid flow between stages within a single vessel shell.
Gas distribution: the claim specifies introducing same amount of chlorine gas to each reactor. Jin the gas amount is determined by specific reaction ratios, which may vary by stage.
Jin teaches a chlorination method using a single reactor divided into multiple reaction unit (stages) where chlorine gas is injected into lower portion and HCl gas is discharged. While Jin primarily focuses on a single multi-stage reactor, it explicitly suggests that the number of reactors may be controlled, depending on the toluene/chlorine ratio.
Regarding series connection: A person of ordinary skill in the art, prior to the effective filling date if the claimed invention would recognize that the internal stage of Jin already function as a series of reaction zones. Moving from a single multi-stage vessel to a plurality of separate vessels connected in series is a routine structural modification. In chemical engineering, staging a reaction can be done either within one tall column or across several smaller columns to achieve the same mass transfer and conversion goals. This is a predictable substitution of one known reactor configuration for another.
Regarding the same amount of gas: Although Jin calculate gas based on ratios a person ordinary skill in the art, prior to the effective filing date of the claimed invention, seeking to simplify plant operation would find it obvious to distribute gas in equal amount across all the reactors. This ensures uniform catalyst loading and simplifies the manifold piping design. Choosing a uniform flow rate is a matter of routine optimization with the scope of Jin’s teaching.
Regarding the HCl discharge: Jin already teaches that HCl may be discharged to the outside of the reactor. In a series of separate reactors, a discharge on each vessel to prevent HCL from the former reactor from entering the later reactor and inhibiting the reaction.
Regarding claim 2, Jin explicitly teaches (see page 8, 6th paragraph; Example 1 and drawings) that the chlorination of toluene is exothermic and requires a cooling unit (40), specifically a shell and tube heat exchanger following each reaction unit (30).
Regarding external heat exchanger: since Jin already teaches (30→40→30), a person of ordinary skill in the art would find it obvious to place these heat exchanger between separate reactors when transitioning from a single multi-stage vessel to a series of individual reactors. Moving a heat exchanger from an internal compartment to an external inter stage position is routine design choice to improve maintenance access and cooling efficiency.
Regarding quantitative introduction: Jin teaches that the reaction liquid flows sequentially. In any series of separate chemical reactors, using a pump or gravity fed flow meter to quantitatively introduce liquid from one vessel to the next is standard engineering practice to ensure stable residence time and prevent reactor overflow.
Regarding low portion entry: Jin teaches injecting reactant into the lower part of the reactor. Extending this teaching o the introduction of the intermediate product from a former reactor t the bottom of a latter reactor ensures proper upward mixing with the chlorine gas (which is also fed to the low portion). This a predictable application of Jin’s flow geometry.
Regarding claim 3, Jin teaches (see page 7, last paragraph and drawings) HCl gas is generated during the chlorination of toluene and must be discharged. It also teaches that the reaction fluid flows sequentially through multiple stages. Since Jin already teaches the necessity of discharging HCl to maintain reaction efficiency, using an intermediate vessel (buffer drum) to ensure the liquid is degassed before entering the next stage is a predictable optimization. If HCl remains in the liquid, it can inhibit the reaction in the next stage. A person ordinary skill in the art, prior to the effective filing date of the claimed invention would find it obvious to vent the buffer drum to the same HCl recovery system mentioned in Jin to improve the overall process yield.
Regarding claim 4, The use of a multi-hole gas sparger in the lower portion of each reactor is directly taught or inherently suggested by Jin. It represents the use of a conventional gas distribution tool in its expected environment to achieve predictable result of efficient chlorination. See page 8, the 5th paragraph from the top.
Regarding claim 5, Jin explicitly teaches a diameter of 1 to 2 mm. The claim range 1 to 5 mm fully includes the range taught in Jin. See page 10, the 4th paragraph from the top.
Regarding claim 6, Jin teacher a chlorine gas linear velocity of 1 to 7 cm/s.
While the claimed range is significantly higher than Jin, the prior art already identifies linear velocity as a critical parameter to be controlled. Moving from the cm/s to the m/s range is a predictable modification for an engineer aiming to scale up production or increase the turbulence and mixing intensity with a column type reactor. See page 4, 4th paragraph from the bottom.
Regarding claim 7, Jin teaches using an excess of toluene to control chlorination. The claimed molar ratio of 1:1/16 to 1/8 represents a routine optimization of this excess aromatic, method for controlling selectivity, as a person ordinary skill in the art, prior to the effective filing date of the claimed invention would find reducing the chlorine ratio to be a predictable way to increase monochlorination and minimize byproduct formation. See page 8, last paragraph.
Regarding claim 8, Jin teaches that the faster the linear velocity the shorter the residence time and the lower the conversion rate of the reactant in certain volume. The conversion rate of the chlorine gas is not 100%. See page 9, 3rd and 5th paragraphs.
A person ordinary skill in the art, prior to the effective filing date of the claimed invention would understand that by operating at the higher liner velocity suggested in the earlier claim, the conversion rate will naturally drop in a lower range, such as 1 to 15%. Since there is no evidence that a conversion rate of 1-15% yields a technically surprising result that differs quantitively from the lower conversion taught as a consequence of process speed in Jin.
Regarding claim 9, Jin explicitly teaches introducing toluene into the lower part of the reactor through a liquid supply nozzle. Jin also teaches that linear velocity of liquid is increased to minimize back-mixing. A person ordinary skill in the art, prior to the effective filing date of the claimed invention, aiming to maximize this effect would naturally increase the feed velocity. This a predictable result, high velocity injection through a nozzle is standard method to ensure the aromatic compound is thoroughly dispersed into the chlorine gas. Since Jin already identifies increased linear velocity as a desirable goal for process efficiency. See page 4, 7th paragraph and page 9 the last paragraph.
Regarding claim 10, Jin taught range of 1 to 7 cm/s falls entirely within the broader claimed limit of 47 cm/s or less. Without a showing that this specific upper limit is critical to the success of the chlorination reaction in a way that the prior art is not, the choice remains a matter of routine optimization. See page 4, the 4th paragraph from the bottom.
Regarding claim 11, Jin explicitly teaches cooling the reaction product to 25 0C which is the upper limit of the claim range. Selecting a slightly lower temperature is a routine optimization of the cooling step described in the prior art. See page 4, the 5th paragraph.
Regarding claim 12, Jin taught range of 0.1 to 2 mm is entirely within the claimed range. When a prior art range falls within or overlaps a claimed range the claim is generally considered obvious. There is no indication that a 5 mm bubble produces a unique technical result compared to a 2 mm bubble. Both sizes function similarly to transport chlorine into the aromatic liquid phase. See page 3, the 3rd paragraph from the bottom.
Regarding claim 13-16, Jin teaches the same catalyst and cocatalyst and the ratio of catalyst to cocatalyst is 1:0.76 or more and 1:0.76 or less. See page 3, last paragraph through page 4, lines 1-5.
A person ordinary skill in the art, prior to the effective filing date of the claimed invention seeking to perform the aromatic chlorination process described in Jin would find it obvious to use the same catalyst, cocatalyst and proportions specified in that same reference.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAFAR F PARSA whose telephone number is (571)272-0643. The examiner can normally be reached M-F 10:00 AM-6:30PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Scarlett Goon can be reached at 571-270-5241. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JAFAR F PARSA/Primary Examiner, Art Unit 1692
Prosecution Insights