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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 July 13, 2026 has been entered.
Claims 1,6,8,9,14,15,19,20 and 25-29 are pending. Claims 2-5,7,10-13,16-18 and 21-24 have been cancelled. Claims 37-29 are new.
All prior rejections are maintained for the reasons set forth below.
Claim Objections
Claim 27 is objected to because of the following informalities: claim 27 recites the pressures in Pa and bara in parenthesis which is redundant, only one unit of pressure should be recited. 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.
Claims 1,6,8,9,14,15,19,20,25,26 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over Schmidt (WO 2004/024826) in view of Gaeng (DE 19831291 A1), Ramanathan (Optimization of Continuous Distillation Columns Using Stochastic Optimization Approaches, Trans IChem E, Vol 79, Part A, April 2001) and Hearn (US 6,169,218).
Schmidt teaches producing highly pure leuco indigo by removing aniline and N-methyl aniline from a 23% aqueous leuco indigo solution (water added prior to distillation) with 0.6% aniline (6000 ppm) and 0.4% N-methylaniline (4000 ppm) using a method of distillation under air exclusion under nitrogen (inert gas) to remove any oxygen wherein 1000 mL of water are distilled off and fresh water can be added (examples 1 and 3, 232, 277-293). Schmidt teaches producing solutions with leuco indigo content of up to 55% by weight and less than 200 ppm aniline and N-methylaniline (136-152). Schmidt teaches oxidizing the leuco indigo after the dye is drawn into the textiles to dye them (93). In example 4, Schmidt teaches a solution in which neither aniline or N-methylaniline can be detected obtained by distillation.
Schmidt does not teach the mixed alkali metal salt ratio and stability which is prevention of crystallization and/or precipitation or the number of theoretical stages. Schmidt does not specify water distilled off in a weight that is at least one and a half times the weight of the aqueous leuco indigo solution and is not more than four times the weight of the aqueous leuco indigo solution. Schmidt also does not teach that the liquid stream comprises 2000ppm-10000ppm aromatic amine, 1000-3000ppm aniline and 500-2000ppm n-methylaniline based on the total weight of the solution, or continuous distillation. Schmidt does not teach the features of the distillation apparatus of the sidewall inlets for the liquid stream and the water stream, mixing of the streams and extraction of the water containing aniline and N-methylaniline at the top of the column and extraction of the leuco indigo solution at the bottom of the column and column packing. Schmidt does not teach the 1.5 to 2.5 mol alkali to 1 mole leucoindigo
Gaeng teaches preparing concentrated leuco indigo solutions by using a mixture of two alkali metal salts, preferably sodium and potassium (page 3, paragraph 1 and 2), preferably in ratios of 3: 1 to 1:3 (claims 1 and 4) to prevent crystallization of the leuco indigo and provide stability to the solutions (page 3, paragraph 4; examples). Gaeng teaches 1.5 to 2.5 mol alkali hydroxide to 1 mole leucoindigo (page 3, paragraph 2)
Ramanathan teaches continuous distillation is the one of the most widely used separation techniques used in chemical processes industry and can be effectively optimized to achieve the desired degree of separation and the lowest total cost (page 310, left column; page 31, left column). Figure 1 demonstrates that the liquid mixture if fed into the sidewall of the column, with the first component being removed from the overhead or top of the columns and the second separated product is removed from the bottom of the column (page 311, Figure 1). Ramanathan teaches the number of theoretical stages is an optimizable parameter that becomes a design variable which results in a tradeoff between the energy and costs to achieve the desired degree of separation at the lowest total cost (page 311, left column).Ramanathan teaches the total number of stages should be optimized (page 312, left column, continuous simple distillation).
Hearn teaches it is standard structure for distillation columns to provide sidewall inlets (Figure 1: 1,2) for two feed streams which are mixed together in the packed column (Figure 4, 312) and extraction of the separated components in different locations one at the bottom of the column (Figure 1: 11,8) and the other from the top of the column (Figure 1: 3,20,9; column 9, lines 1-55).
It would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the methods of Schmidt by preparing a mixed salt leuco indigo with sodium and potassium present in the claimed ratio of 4:1 to 8:1 or 5:1 to 7:1 as Gaeng teaches the sodium and potassium salts are effectively used in any mixture wherein a ratio of 3:1 to prevent crystallization and precipitation of the leuco indigo for solution stability is preferred and that 1.5 to 2.5 mole alkali should be used per mol leucoindigo. While the 3:1 ratio is 75%:25% is slightly outside applicant’s 4:1 ratio which is 80%:20% or 5:1 ratio which is 83% to 17%. Any mixture of sodium hydroxide and potassium hydroxide is permitted, and the 70-30% mole content of a single hydroxide is simply preferred an not limiting as the claimed 3:1 is 75% mol% to 25 mol%. Accordingly selecting any mixture of sodium and potassium hydroxide particularly 4:1 to 8:1 or 5:1 to 7:1, would just require routine skill in the art. It is noted that the solution stability for a 75% to 25% ratio of sodium to potassium is still provided and crystallization is still prevented, which is the same benefits desired by applicant. Selecting from the claimed ratios for the identical benefit of solution stability and crystallization prevention is obvious through routine experimentation. A prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties, see Titanium Metals Corp. of America v. Banner, 778F.2d 775,227 USPQ 773 (Fed. Cir. 1985). See MPEP 2144.051. While Gaeng teaches a maximum 70 mol % potassium or sodium salt, claim 5 clearly teaches a 75%:25% molar ratio which is outside the range and therefore the maximum 70% is not limiting of Gaeng. Using the claimed concentrations of sodium and potassium to produce mixed salts of leuco indigo is clearly taught by Gaeng as beneficial to stability of the solution, particularly preventing crystallization. Further three salts can be used in the leuco indigo mixture wherein lithium hydroxide can also be included, so in a ratio of three hydroxide salts it is possible to have the claimed 5:1 to 7:1 ratio without exceeding 70% of the entire hydroxide, for example 50% sodium hydroxide, 10% potassium hydroxide and 40% lithium hydroxide. None of the hydroxide exceed 70% and the ratio of sodium to potassium is 5:1.
It would have been obvious to one of ordinary skill in the art at time the time the invention was made to modify the methods of Schmidt by performing the step where water is distilled off in a weight that is at least one and a half times the weight of the aqueous leuco indigo solution and is not more than four times the weight of the aqueous leuco indigo solution and arriving at 2.0ppm or less of N-methylaniline as Schmidt clearly teaches distilling with water to arrive at less than 200 ppm aniline and N-methylaniline. Less than 200ppm includes values of 2.0-0ppm and examples of Schmidt include undetectable levels of N-methylaniline. Schmidt teaches achieving these levels of aniline and N-methylaniline by distillation in example 4. Using any method of distillation and level of water distilled off to arrive at undetectable levels of aniline and N-methylaniline such as 0 ppm would be obvious as maximal removal of these contaminants is desired and undetectable levels are achievable.
It would have been obvious to one of ordinary skill in the art at the time the invention was made to prepare the leucoindigo solutions of Schmidt by using the continuous distillation methods with optimization to 5-50 or 10-40 theoretical stages as Ramanathan teaches this method is one of the most widely used separation techniques in the chemical process industry and can be optimized by adjusting the number of stages to a value that achieves the desired degree of separation but at the lowest cost.
It would have been obvious to use the standard distillation apparatus structure taught in Hearn in the methods of Schmidt, as Hearn teaches this is a conventional distillation apparatus). Schmidt invites the inclusion of distillation and Ramanathan teaches continuous distillation is one of the most widely used techniques to obtain a desired separation of components while Hearn teaches the claimed distillation method of mixing a water stream with liquid stream, and distilling the combined stream and separating components in the claimed process is conventionally used in the art.
It would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the methods of Schmidt by using a liquid stream of 2000ppm-10000ppm aromatic amine, 1000-3000ppm aniline and 500-2000ppm n-methylaniline based on the total weight of the solution would be obvious as Schmidt teaches methods of removing aniline and N-methylaniline from leuco indigo in similar distillation methods with aqueous leuco indigo solutions and producing leuco indigo solution of a content of up to 55% by weight and any value less than 200 ppm aniline and N-methyl aniline. Schmidt is not limited to the values of the working example and the methods are applicable to any leuco indigo solution with any level of initial aniline and N-methyl aniline. Schmidt recognizes the need to add water to provide an aqueous leuco indigo solution and distill off the water and add fresh water if the distilled leuco indigo solution requires dilution.
Applicant has not demonstrated the criticality of the liquid stream having 2000ppm-10000ppm aromatic amine, 1000ppm-3000ppm aniline and 500-2000ppm N-methylaniline based on the weight of the solution therefore these parameters could obviously be achieved through routine experimentation by one of ordinary skill in the art to arrive at a leuco indigo solution with less than 40 ppm aniline and N-methylaniline. Ramanathan teaches the process of continuous distillation can be optimized to the desired level of separation of components, therefore any starting level of aromatic amine, particularly aniline or N-methylaniline could be removed to a final solution of less than 40 ppm through optimization of the continuous distillation process. It would have been obvious to one of ordinary skill in the art at the time the invention was made to optimize the number of theoretical stages through routine experimentation for best results. As to optimization results, a patent will not be granted based upon the optimization of result effective variables when the optimization is obtained through routine experimentation unless there is a showing of unexpected results which properly rebuts the prima facie case of obviousness. See In re Boesch, 617 F.2d 272,276,205 USPQ 215,219 (CCPA 1980). See also In re Woodrufl 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936-37 (Fed. Cir. 1990), and In re Aller, 220 F2d 454,456,105 USPQ 233,235 (CCPA 1955).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Schmidt (WO 2004/024826) in view of Gaeng (DE 19831291 A1), Ramanathan (Optimization of Continuous Distillation Columns Using Stochastic Optimization Approaches, Trans IChem E, Vol 79, Part A, April 2001) and Hearn (US 6,169,218) and further in view of Davidson (US 2,130,878) and JP H0199603.
Schmidt, Gaeng, Ramanathan and Hearn are relied upon as set forth above.
Schmidt, Gaeng, Ramanathan and Hearn do not teach the pressures and temperatures of the distillation.
Davidson teaches that distilling leucoindigo is effectively accomplished at 95°C at sub atmospheric pressure (below 1 atm, below 1.013 bar) to remove aniline and methylaniline (claim 1).
JP H199603 teaches that conventional distillation columns contain a thermometer at the bottom of the column to measure and control the temperature as well as adjust for fluctuations (page 3, first paragraph).
It would have been obvious to one of ordinary skill in the art at the time the inventions was made to modify the methods of Schmidt, Gaeng, Ramanathan and Hearn by removing aniline and N-methylaniline by distillation at the claimed temperatures and pressures as Davidson teaches sub atmospheric pressure and temperatures of 95°C are effective for removal of aniline and methylaniline. It would have been obvious to measure the temperature at the bottom of the distillation column and control the temperature of the process as JP H199603 teaches this is an efficient way of temperature of a distillation process. Performing distillation for removing of aniline and methylaniline at art recognized temperatures and pressure and monitoring temperatures of the distillation process using standard distillation columns with thermometers located in the bottom is obvious.
Claim 28 is rejected under 35 U.S.C. 103 as being unpatentable over Schmidt (WO 2004/024826) in view of Gaeng (DE 19831291 A1), Ramanathan (Optimization of Continuous Distillation Columns Using Stochastic Optimization Approaches, Trans IChem E, Vol 79, Part A, April 2001) and Hearn (US 6,169,218) and further in view of Csendes (US 2002/0017450).
Schmidt, Gaeng, Ramanathan and Hearn are relied upon as set forth above.
Schmidt, Gaeng, Ramanathan and Hearn do not teach heat entering the column equals heat removed.
Csendes teaches that distillation columns for separating impurities from a liquid are effectively run under adiabatic conditions wherein no loss of heat occurs (paragraph 0005, 0007).
It would have been obvious to one of ordinary skill in the art at the time the inventions was made to modify the methods of Schmidt, Gaeng, Ramanathan and Hearn by using adiabatic distillation methods as Csendes teaches these methods are effective at removing impurities from a liquid during distillation and have no loss of heat. Using a known effective distillation method to effectively remove impurities from a liquid is obvious.
Response to Arguments
Applicant's arguments filed regarding Schmidt have been fully considered but they are not persuasive. It is the examiner’s position that all the references are reasonably pertinent because they relate to leucoindigo purification from aniline or methylaniline or relate to standard distillation techniques and equipment. The examiner argues applicant tis using routine distillation processes and equipment recognized in the art as useful for impurity removal from liquids in particular removal of aniline or methylaniline from leucoindigo solutions containing water and the same alkali. The references cited show it is known to remove these impurities from leucoindigo at similar pressure, temperatures of the distillation columns and the distillation as a process conventionally uses theoretical stages to reach a desired level of purity. This process is a standard calculation and process adjustment based on purification levels desired. The prior art teaches treating the same concentration leucoindigo solutions by distillation to remove the aniline and n-methylaniline to the claimed degree. The examples of the prior art do not need to show every claimed limitation in a single step, rather the selection of the purification methods, concentrations of the leucoindigo solutions can be selected from the broad teachings of the prior art. Further substituting or incorporating efficient methods of distillation known such as continuous distillation and optimizing the number of theoretical stages, temperatures and pressures of treatments is obvious to achieve the desired purification level.
The examiner repeats prior arguments that Ramanathan teaches continuous distillation is the one of the most widely used separation techniques used in chemical processes industry and can be effectively optimized to achieve the desired degree of separation and the lowest total cost and a crucial variable in the optimization to desired level of separation is the choice of the number of theoretical stages in the distillation. Since Ramanathan clearly teaches the importance of optimizing this parameter to provide a balance between degree of separation and total costs, it would have been obvious to arrive at the claimed number of theoretical stages for separation. Using a known distillation process effective for separation is obvious to substitute for another type of distillation also used for separation as both processes achieve the same result removing contaminants. Schmidt is not limited to the teachings in the examples and must be considered for the broad teachings also. Schmidt teaches producing solutions with leuco indigo content of up to 55% by weight and less than 200 ppm aniline and N-methylaniline (136-152). Using a known continuous distillation technique and optimizing the number of theoretical stages to achieve a desired degree of separation is conventionally performed in the art and would be advantageous to apply to the distillation of Schmidt to produce a concentrated leucoindigo content of up to 55% by weight and less than 200 ppm aniline and N-methylaniline as Schmidt also teaches distillation for separation of contaminants. Hearns is simply relied upon for the standard structure of distillation column, not for the compounds being distilled. The columns of Hearns are useful to distill materials other than hydrocarbons. No distillation column is limited to only separating an exemplified hydrocarbon, but rather can be applied to extensive species of other materials to be separated. Applicant has not demonstrated any unexpected results in a manner commensurate in scope with the clams and directly comparing to the prior art of record to establish that these common adjustments are anything more than standard distillation optimizations. Accordingly, the rejections are maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AMINA S KHAN whose telephone number is (571)272-5573. The examiner can normally be reached on Monday-Friday, 9am-5:30pm EST.
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/AMINA S KHAN/Primary Examiner, Art Unit 1761
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