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 § 102/103
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 –
(a)(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.
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 1-5 are rejected under 35 U.S.C. 102((a)(1)) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Chinese Patent Publication No. CN105502490A (published 20 April 2016) as evidenced by Nayak et al. (Scientific Reports, 2016, 6, 26404).
In regard to claim 1, CN105502490A, herein referred to as CN ‘490A, teaches a zirconium hydroxide powder with an average pore diameter of 2.0-2.4 nm and a pore volume of 0.20-0.25 cm3/g [0008]. CN ‘490A does not disclose a full pore distribution via the BJH method which indicates a peak top in the distribution curve (which would correspond to the mode of distribution) between 1-5 nm. However, Since the range of average pore diameters disclosed by CN ‘490A is centered in the instantly claimed pore diameter range, it is the position of the examiner that the top of the pore distribution curve as evaluated by the BJH method for the disclosed zirconium hydroxide powders is within the range of 1-5 nm as instantly claimed and therefore the limitation is anticipated by CN ‘490A.
As a demonstration, Nayak et al. provides a full pore distribution curve (evaluated by the BJH method) for an amorphous zirconium hydroxide powder prior to any calcination treatment. The distribution curve indicates that zirconium hydroxide powders have a narrow bell-curve shaped distribution centered at the mode/mean pore diameter (Figure 2c) and the range immediately around the peak of the curve contributes overwhelmingly to the total pore volume (pp. 4, lines 10-14). Therefore, as the average pore size of the materials in CN ‘490A, 2.0-2.4 nm, the peak of a pore distribution curve is expected to be centered directly in the range of 2.0-2.4 nm or slightly shifted to a lower/higher size that is still between 1-5 nm as instantly claimed. Given the narrowness of the BHJ pore distribution, it is further expected that an overwhelming majority of the pores contributing to the total pore volume are between 1-5 nm wide, and therefore the majority of the disclosed pore volume (0.20-0.25 cm3/g) would comprise pores between 1-5 nm. Examples 1-4 (physical properties in Table 1) have average pore sizes ranging from 2.10-2.25 and pore volumes greater than 0.23 cm3/g. It would have been obvious to one of ordinary skill that the disclosed zirconium hydroxide powders have a pore volume of greater than or equal to 0.15 cm3/g for pores with a diameter between 1-5 nm.
Furthermore, even if from the information disclosed by CN ‘490A is not considered sufficient to anticipate a peak height in the pore distribution of between 1-5 nm and that pores of a diameter between 1-5 nm contribute at least 0.15 cm3/g of pore volume, the instantly claimed limitations still would have been obvious to one of ordinary skill. A person of ordinary skill in the art at the relevant time would have arrived at the instantly claimed pore size and volume through process optimization based on CN ‘490A’s teachings that materials with very small mesopores in a narrow size range and a high pore volume are exceptionally effective at adsorbing phosphates and sulfates [0004]. It has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 2, CN ‘490A discloses zirconium hydroxide powders with average pores sizes ranging from 2.10-2.25 nm and total pore volumes ranging from 0.231-0.245 cm3/g. As noted above, the most commonly observed pore size contributes the majority of the total pore volume in typical amorphous zirconium hydroxide powders (as per Nayak et al.). Therefore, it is the examiner’s position that the materials disclosed in CN ‘490A, with total pore volumes significantly greater than the threshold instantly claimed, have a pore volume of pores between 1-5 nm in diameter, that is 0.20 cm3/g or greater. Furthermore, it would have been obvious to one of ordinary skill in the art to optimize the pore volume contributions of pores between 1-5 nm in diameter because of the teachings of CN ‘490A’s general disclosure which indicates that pore size, distribution, and volume are key variables in a material’s ability to adsorb specific chemical species (see above rejection of claim 1) and since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 3, CN ‘490A does not disclose the bulk density of the zirconium hydroxide powders taught. However, given that CN ‘490A teaches the same material (zirconium hydroxide, with a standard molecular weight) with the same pore size distribution and pore volume (see above rejections), it is the position of the examiner that the optimized zirconium hydroxide powders of CN ‘490A would necessarily possess the bulk density instantly claimed as bulk density measures the distribution of solid mass over a given volume.
In regard to claim 4, CN ‘490A teaches that the zirconium hydroxide powders disclosed have specific surface areas of greater than or equal to 550 m2/g ([0008], and see Examples 1-4 in Table 1) as instantly disclosed (≥350 m2/g).
In regard to claim 5, CN ‘490A teaches that zirconium hydroxide powders are prepared by a wet method [0010]-[0014] and then dried at 50-120°C to a solid concentration of 75-95 wt% ([0015], reported as 5-25 wt% moisture). The disclosed solid concentration overlaps the instantly claimed solid concentration range of 60-87 mass%.
CN ‘490A does not teach a condition of the drying process that the increase rate of solid concentration is 5-120% mass/h. CN ‘490A provides drying temperatures and final solid concentrations, but not the time for which the powders were dried for. However, optimizing the drying conditions of CN ‘490A for a specific rate of increase in solid concentration, given both the disclosure of acceptable drying temperatures and moisture content, would only require a person of ordinary skill in the art to determine an optimal drying time and in-range temperature. As discussed in Nayak et al., thermal treatment was well-understood to affect the final physical properties of zirconium hydroxide powders through sintering and pore collapse, as seen through predictable negative trends in specific surface area, positive trends in pore size (if present), and the transformation of pore shape as temperatures increase (Table 1). Therefore, it would have been obvious to one of ordinary skill in the art at the relevant time, to modify the teachings of CN ‘490A to control the evaporation rate of water in the wet zirconium hydroxide powders to be between 5-120% mass/h by optimizing the drying temperature and time, in order to exert fine control over changes to the internal pore structure and size as suggested by Nayak et al.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over CN '490A in view of Nayak et al. applied to claim 5 above, and further in view of Liu et al. (Materials & Design, 2017, 128, pp. 80-85).
In regard to claim 6, CN ‘490A teaches a final solid concentration of 75-95 wt%, which encompasses the instantly claimed solid concentration range of 87-92% by mass [0015]. As noted above in regard to claim 5, the final solid concentration of the wet cake/zirconium hydroxide powder would have been obvious to one of ordinary skill in the art at the time of invention to select the portion of the prior art’s range which is within the range of the applicants’ claims because it has been held prima facie case of obviousness to select a value in a known range by optimization for the results. In re Aller, 105 USPQ 233. Additionally, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time invention was made to have selected the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
CN ‘490A does not teach a 2-step drying process in order to dry the wet filter cake of zirconium hydroxide produced. However, multistep drying, or annealing, is a common practice in the art, and often serves the purpose of preventing the formation of faults, fractures, or other defects during rapid temperature changes in solid materials. In the context of zirconium materials, Liu et al. teaches the use of a multistage drying method to dry zirconium boride films, wherein the prepared precursor slurry is dried for 20 min at 70°C, 40 min at 60°C, 30 min at 40°C, and then naturally cooled to room temperature (pp. 82, left column, 1st paragraph). As multistage drying is well-known in the art for preventing defects, and CN ‘490A teaches a range of solid concentration/moisture content which overlaps both the first drying step and second drying step instantly claimed, it would have been obvious to one of ordinary skill in the art at the relevant time to modify the method taught by CN ‘490A by splitting the singular drying step into two or more steps, wherein a first, higher temperature is used followed by a lower temperature, in order to further improve the structural homogeny of the final materials as is known in the art.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Chinese Patent Publication No. CN105435733A, English machine translation attached herein, which describes a large-particle-size zirconium hydroxide powder with a specific surface area above 350 m2/g, a total pore volume, of 0.16-0.22 cm3/g, and an average pore diameter of 2.01-2.35 nm.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MORDECAI M LEAVITT whose telephone number is (571)272-6637. The examiner can normally be reached Monday-Friday 8AM-5PM.
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/MORDECAI M LEAVITT/Examiner, Art Unit 1742 /CHRISTINA A JOHNSON/Supervisory Patent Examiner, Art Unit 1742
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