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 .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application No. EP21386015.8, filed on 23 February 2021.
Information Disclosure Statement
The information disclosure statements (IDS) filed on 23 August 2023 and 6 August 2025 are acknowledged and have been considered by the examiner.
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 1-5, 7-11, and 14-19 are rejected under 35 U.S.C. 103 as being unpatentable over Li (US 20190150396A1, published 23 May 2019) in view of PCT Application Publication No. WO 97/06671 (published 27 February 1997) as evidenced by Pedersen & Surlyk (Bull. Geolg. Soc. Denmark., 32, 1983, pp. 43-65), Kiviranta et. al. (Posiva Oy, Dec 2011), and Dolley (USGS Minerals Yearbook; 2003, pp. 23.1-23.6).
In regards to claim 1, Li teaches a particulate material (e.g. absorbent granules) comprising an absorbent core and a coating layer (a two-layer coating on the core, paragraph [0018]). Li further teaches that the coating may be comprised of activated carbon, a binder, sodium bentonite, and water (paragraphs [0007], [0009], [0051]). Li further teaches that bentonite is a mineral rich in montmorillonite, which is a smectite clay (paragraph [0071]).
Li does not teach that the core comprises naturally-occurring argillaceous (clayey) diatomite.
However, WO ‘671 teaches an absorbent particle for use as an animal litter comprising a substrate, clumping particles, and superabsorbent particles (line 36, pp. 4 – line 4, pp. 5), wherein the substrate is preferably comprised of natural moler, such as the type found at Mors in Denmark, (lines 1-3, pp. 6). Further, moler acts as a non-swelling clayey material, which prevents excessively physical swelling of an animal litter upon ingestion by an animal (lines 1-10, pp. 6).
As evidenced by Pedersen & Surlyk, moler is generally understood to contain 65 wt% diatomite (e.g. diatoms; second paragraph, right column, pp. 60), smectite-rich clays, and small quantities of other minerals (sixth paragraph, left column, pp. 62). Li teaches that the core may be an agglomerate which comprises clay (paragraph [0024]). By this definition, moler would be a naturally-formed agglomeration of diatomite and clay and is an appropriate alternative material for the core taught by Li. It would have been obvious to one of ordinary skill in the art of the time to modify the absorbent granules taught by Li to use moler as the core material as suggested by WO ‘671 in order to carefully control the swelling of the final material.
Li does not explicitly teach that the mineral used in the coating layer is 70 wt% smectite clay.
However, bentonite is understood in the art to be rich in the smectite mineral montmorillonite (Li, paragraph [0071]. While the exact amount of montmorillonite and other smectites contained in bentonite varies by locality, it is generally above 70 wt%. As evidenced by Kiviranta et al., bentonite samples originating from Wyoming and Milos were found to contain 79 wt% and 88 wt% smectite respectively (paragraph 2, Abstract). It would have been obvious to one of ordinary skill in the art at the time to select a bentonite which contained >70 wt% smectites as it was easily accessible and the clay particles are responsible for the swelling properties of the material (i.e. the clumping properties, Li paragraph [0069]).
In regard to claim 2, as discussed above bentonite is rich in the smectite montmorillonite (Li, paragraph 0071]), with samples from various localities containing above 75 wt% smectites. It would have obvious to one of ordinary skill in the art to select a bentonite for use in the coating layer taught by Li that contains >75 wt% smectites as it is a commonplace physical property and positively contributes to the swelling/clumping properties of the material.
In regard to claim 3, Li teaches that the coating layer may contain a binder (paragraphs [0007], [0025]).
In regard to claim 4, as evidenced by Pedersen & Surlyk, the naturally-occurring moler is generally understood to contain 65 wt% diatomite with the remaining minerals being majority smectites and trace minerals. Further, as evidenced by Dolley, moler may contain up to 30 wt% clays (lines 10-11, right column, pp. 23.1). Therefore, the combined teachings of Li and WO ‘671 would result in the composition of the naturally-occurring argillaceous diatomite being at least 60 wt% diatomite and at least 20 wt% smectite on account of those amounts being inherent to moler’s mineral composition.
In regard to claim 5, Li does not teach the use of moler as a material in the absorbent core, but WO ‘671 teaches the use of moler as a second material (lines 1-3, pp. 6), and would be obvious to modify the core of Li with moler as taught by WO ‘671 as previously described in regard to claim 1.
In regard to claim 7, Li does not disclose the porosity or distribution of pore sizes of the materials used to form the absorbent granules. The material which is used in the core is defined as being a naturally-occurring argillaceous diatomite. As a naturally-occurring material which, in light of the specification, is not modified in a way that would affect the distribution of pores of various sizes, it is expected that the size distribution of pores in the naturally-occurring argillaceous diatomite is inherent to the natural material. Therefore, any art which utilizes the same naturally-occurring materials would share the claimed range of pores in the macroporosity area. As WO ‘671 utilizes moler, which meets the definition of naturally-occurring argillaceous diatomite as discussed in regard to claim 1, it is the examiner’s position that the disclosed moler would comprise around 25-60 vol% pores in the macroporosity area.
In regard to claim 8, neither Li or WO ‘671 disclose the porosity or distribution of pore sizes of the materials used to form the absorbent granules. As discussed in regard to claim 7, it is the examiner’s position that as the material chosen is specifically naturally-occurring and no preparation steps indicated in the preparation in the specification are expected to chemically or mechanically change the porosity of the starting material. Therefore, a naturally-occurring argillaceous diatomite such as moler would have a distribution of pores in the meso- and microporous areas within the claimed ranges.
In regard to claim 9, Li teaches that sodium bentonite, a swelling clay, may be used in the coating layer (paragraph [0071]). Bentonite (either Na-bentonite or Ca-bentonite) is known in the art to be primarily composed of montmorillonite (Kiviranta et al., page 31, Section 3.2.3, paragraphs 1 & 2).
In regard to claim 10, Li teaches the use of bentonite (specifically sodium bentonite) as a clumping agent in the coating layer (paragraph [0069]).
In regard to claim 11, Li teaches that the absorbent granules may have a composition comprising the following ranges: 0.5/12 wt% water, 0.02-5 wt% binder, 25-60 wt% core material, 0.1-10 wt% activated carbon, 20-75 wt% bentonite (paragraphs [0051], [0052], [0058], [0066], [0072]). In example 1, Li discloses an absorbent product manufactured with 1.14 g CMC as a binder, 568 g water, 22.7 g activated carbon, 567 g perlite cores, and 1701 g sodium bentonite (paragraph [0082]) which is then dried (paragraph [0082]). Of the dry components, the expanded perlite cores account for 24.7 wt% while the components of the coating layer account for 75.3 wt%. The method does not disclose the exact moisture content after drying, but assuming an extreme as disclosed by the specification of 12 wt% (paragraph [0051]), the core is 21 wt% of the core while the coating layer is 79 wt% of the particle. Under both assumptions, the wt% of the core and coating layer are within the claimed ranges.
In regard to claim 14, Li teaches a method of forming an absorbent granule by contacting a core material (modified by WO ‘671 to be a naturally-occurring argillaceous diatomite) with a composition comprising a mineral containing smectite in a laboratory rotary coating machine (expanded perlite cores coated in carbon slurry, followed by sodium bentonite powder; paragraph [0082]).
In regard to claim 15, Li teaches that the absorbent granules taught may be used as an absorbent animal litter (paragraph [0006]).
In regard to claim 16, Li does not disclose the porosity or distribution of pore sizes of the materials used to form the absorbent granules. As discussed in regard to claim 7, it is the examiner’s position that as the material chosen is specifically naturally-occurring and no preparation steps indicated in the preparation in the specification are expected to chemically or mechanically change the porosity of the starting material, a naturally-occurring argillaceous diatomite such as moler would share the claimed distribution of pores in the macroporous area.
In regard to claim 17, Li does not disclose the porosity or distribution of pore sizes of the materials used to form the absorbent granules. As discussed in regard to claim 7, it is the examiner’s position that as the material chosen is specifically naturally-occurring and no preparation steps indicated in the preparation in the specification are expected to chemically or mechanically change the porosity of the starting material, a naturally-occurring argillaceous diatomite such as moler would share the claimed distribution of pores in the meso- and microporous areas.
In regard to claim 18, Li does not teach the use of moler as a material in the absorbent core, but WO ‘671 teaches the use of moler as a second material (lines 1-3, pp. 6), and would be obvious to modify the core of Li with moler as taught by WO ‘671 as previously described in regard to claim 1.
In regard to claim 19, as described in regard to claim 9, Li teaches that sodium bentonite may be used as the primary mineral in the coating layer of the absorbent granules.
Claims 6, 12, 13, & 20 are rejected under 35 U.S.C. 103 as being unpatentable over Li and WO ‘671 as applied to claim 1 above, and further in view of Jiang et. al. (U.S. Pub. No. 20170265428A1, published 21 September 2017).
In regard to claim 6, Li and WO ‘671 do not teach that the naturally-occurring argillaceous diatomite is calcined. However, Jiang et. al. teaches embodiments of an absorbent particle where calcined diatomaceous earth is used as a non-clumping component of the particle (lines 15-24, paragraph [0052]). Jiang et. al. further teaches that high compressive strength of the non-clumping particle can be achieved through calcination (lines 4-7, paragraph [0052]). Jiang et. al. links compressive strength of the non-clumping material to a resilience of the particulate matter to not collapse when wet. One of ordinary skill in the art would find it advantageous to apply the thermal treatment of calcination to the equivalent non-clumping/non-swelling material in the teaches of Li and WO ‘671, moler, to improve the compressive strength of the absorbent material. Therefore, it would have been obvious to one of ordinary skill at the relevant time to modify the teachings of Li and WO ‘671 to include calcining the naturally-occurring argillaceous dolomite (moler) improve compressive strength and clumping ability of the absorbent material.
In regard to claim 12, Li and WO ‘671 are silent on the bulk density of the particulate material/granules made. However, Jiang et. al. teaches an absorbent material comprising diatomaceous earth as a non-clumping/non-swelling material and sodium bentonite with a bulk density of 673 kg/m3, which is within the instantly claimed range (50:50 ratio, Table 2, pp. 8). Jiang et. al. further teaches that there is an optimal range of densities for an animal litter, where lower density is desirable for ease of use but too low of a density may lead to dustiness and high dispersal (paragraph [0006]). These teaching establish bulk density as a results-effective variable which a person of ordinary skill would aim to optimize in a product. It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed range of bulk density through process optimization, 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 13, Li and WO ‘671 are silent on the water absorptivity of the particulate material/granules made. However, Jiang et. al. teaches an absorbent material comprising diatomaceous earth as a non-clumping/non-swelling material and sodium bentonite with a water absorptivity of 309 wt%, which is within the instantly claimed range (50:50 ratio, Table 2, pp. 8). Jiang et. al. further teaches that high absorptivity is important to prevent slacking (the inability of a litter to retain clumps) and to function effectively as a litter (paragraph [0005 and [0007]). WO ‘671 teaches that a particulate material which has a high water absorptivity may pose a negative ingestion risk for animals and thus should be avoided (lines 9-14, pp. 6). These teaching establish bulk water absorptivity as a results-effective variable which a person of ordinary skill would aim to optimize in a product. It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed range of water absorptivity (wt%) through process optimization, 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 20, Li and WO ‘671 are silent on the bulk density and water absorptivity of the particulate material/granules made. A material with a 50:50 ratio of sodium bentonite to diatomaceous earth is disclosed to have a water absorbency of 309 wt% and a dry bulk density of 673 kg/m3 (50:50 ratio, Table 2, pp. 8). As discussed in regard to claims 12 and 13, Jiang et. al. teaches that it is preferable to have a material with a bulk density below 800 kg/m3 and a water absorptivity of 10-400 wt% of the absorbent material (paragraphs [0012] and [0023]). Further as discussed in regards to claims 12 and 13, the teachings of Li, WO ‘671, and Jiang et. al. establish that bulk density and water absorptivity of a particulate material for animal litters are results-effective variables and that one of ordinary skill would aim to optimize. It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed ranges of bulk density and water absorptivity through process optimization, 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.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US Patent Application Publication No. US20110185977A1; US Patent Application Publication No. US20160135421A1.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, CHRISTINA JOHNSON can be reached at (571) 272-1176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MORDECAI M LEAVITT/Examiner, Art Unit 1742 /CHRISTINA A JOHNSON/Supervisory Patent Examiner, Art Unit 1742