DETAILED ACTION
Status of Claims
1. Acknowledgement is made of the amendments filed 06/19/2026. Upon entering the amendments, claims 1-11 and 25 are canceled and claims 26-37 are added. Claims 12-24 and 26-37 are pending and presented for the examination.
Election/Restrictions
2. Applicant’s election without traverse of invention II, claims 12-24, in the reply filed on 06/19/2026 is acknowledged. New claims 26-37 depend from the elected claims and thus properly belong with the elected invention.
Notice of Pre-AIA or AIA Status
3. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
4. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
5. The information disclosure statements (IDS) submitted on 01/18/2024, 06/02/2025, 06/09/2025, 05/13/2026, and 08/21/2026 are being considered by the examiner.
Claim Rejections - 35 USC § 112
6. The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
7. Claims 17, 22-24, and 27-29 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 17 contains a brand name as the only further limitation to the mixer type. >>>>>>>>>>>
Claims 22, 23, and 29 contain limitations to ratios of closed porosity to open porosity, but give these ratios in terms of a percentage. As a ratio would properly be given as a x:y value, it is likely that the values/ranges of said claims are meant to be the percentage of total porosity that is closed. The claims will be interpreted as such for examination on merits herein.
Claim 24 recites a total pore volume, but gives the unit for this as grams/cm3. The proper unit for this property should be cm3/gram.
Claim 27 recites a limitation to the “foam quality” of the foaming agent. However, the instant Specification does not further define the nature of this foam quality property, and the term is not sufficiently known in the art so as to unambiguously convey to a skilled artisan which foaming agents would be covered by the claim. Claim 27 is therefore indefinite under USC 112.
Claim 28 is indefinite as depending from claim 27 and thus including the ambiguous limitations thereof.
Claim Rejections - 35 USC § 103
8. 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.
9. 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.
10. 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.
11. Claims 12-13, 18-24, 29, and 31-37 are rejected under 35 U.S.C. 103 as being unpatentable over Perich et al (US 5766686 A).
Regarding claim 12, Perich et al teaches a coating composition for refractory articles, said composition comprising a binder component along with a foaming agent component. The binder component is preferably colloidal silica (see column 3, lines 20-25) with a silica content of 40 wt%, and thus having a water content of 60 wt%. The colloidal silica binder is present in an amount of 25-75 wt% (see claim 2) and the foaming agent is present in an amount of 0-5 wt% (ibid.). When using the aforementioned 60 wt% water present in the colloidal silica binder solution, this constitutes 15-45 wt% water. The 0-5 wt% range for the foaming agent content would thus lead to a foaming agent-to-water ratio range that overlaps that of the instant claim 12. Perich et al only teaches an exemplary embodiment comprising 2.2 wt% foaming agent, resulting in a ratio that is from 1:6.8 to 1:20.5. However, lower values within the 0-5 wt% range taught by Perich et al for the foaming agent component would lead to ratios falling within the 1:25-1:1500 range of the instant claim. In combination with a water content of 15 wt%, the foaming agent content range of 0.01-0.6 wt% would result in a ratio falling within the instant claim range. For a water content of 45 wt%, a foaming agent content range of 0.03-1.8 wt% would result in a ratio falling within the instant claim range. As such, routine optimization and experimentation with the ranges of Perich et al would result in a colloidal silica/water/foaming agent mixture meeting the compositional limitations of instant claim 12.
Perich et al teaches that producing the inventive coating composition comprises adding the foaming agent component to the water present in the colloidal silica sol. The sol is necessarily produced by adding the 40 wt% colloidal silica taught by Perich et al to water. Each process step limitation of the instant claim is therefore met by the teachings of Perich et al.
Perich et al does not teach the porosity or total pore volume of the binder itself, and does not teach a half-life of said binder. However, as discussed above, Perich et al teaches a composition that comprises colloidal silica, water, and foaming agent in amounts that, through routine optimization and experimentation, would be equivalent to those of the instant claim. This equivalently composed mixture is produced according to steps meeting the instant process limitations. The resultant binder component would therefore necessarily also have an equivalent porosity and total pore volume to that of the instant claims, as these values flow from the amount and type of foaming agent used. It is well settled that when a claimed composition appears to be substantially the same as a composition disclosed in the prior art, the burden is properly upon the applicant to prove by way of tangible evidence that the prior art composition does not necessarily possess characteristics attributed to the CLAIMED composition. In re Spada, 911 F.2d 705, 15 USPQ2d 1655 (Fed. Circ. 1990); In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980); In re Swinehart, 439 F.2d 2109, 169 USPQ 226 (CCPA 1971).
Similarly, the equivalent binder/foaming agent mixture taught by Perich et al would also necessarily have an equivalent half-life to that instantly claimed. Each limitation of claim 12 is therefore met by Perich et al, and the claim is obvious and not patentably distinct over the prior art of record.
Regarding claim 13, Perich et al teaches that the foaming agent (MEARLCEL 3532) is added directly to the aqueous colloidal silica (see column 5, lines 20-35).
Regarding claims 18-19, as above, the ranges taught by Perich et al for the foaming agent and colloidal silica sol binder components are such that the ratio ranges resultant therefrom would overlap and thus render obvious the 1:50-1:750 and 1:50-1:200 ranges of claims 18 and 19.
Regarding claims 20-21, as discussed above, Perich et al teaches an equivalently composed mixture that is produced by a process meeting the limitations of instant claim 12. This resultant mixture would necessarily have equivalent porosity properties, and would therefore necessarily meet the further limitations of said claims 20 and 21.
Regarding claims 22-23 and 29, as discussed above, Perich et al teaches an equivalently composed mixture that is produced by a process meeting the limitations of instant claim 12. This resultant mixture would necessarily have equivalent porosity properties, and would therefore necessarily have a percentage of closed porosity as compared to total porosity of at least 70%, 80%, or 90%.
Regarding claim 24, as discussed above, Perich et al teaches an equivalently composed mixture that is produced by a process meeting the limitations of instant claim 12. This resultant mixture would necessarily have equivalent porosity properties, and would therefore necessarily have a total pore volume of 1.15-7.0 cm3/g.
Regarding claim 31, Perich et al teaches that the colloidal silica sol and foaming agent are mixed prior to introduction of refractory material. At this stage the mixture of colloidal silica sol and foaming agent constitute a binder meeting the limitations of claim 12, and as such the binder is mixed separately before mixing with additional refractory ingredients.
Regarding claims 32-34-, as discussed above, the Perich et al binder mixture of colloidal silica sol and foaming agent is equivalently composed to that of the instant claims and necessarily has equivalent porosity properties. As such, the Perich et al mixture would also necessarily have an equivalent density, as said density is resultant from porosity. The Perich et al foamed binder would thus have a density of at least about 0.130 g/cm3, 0.195 g/cm3, and 0.260 g/cm3.
Regarding claims 35-37, as above, the equivalent Perich et al binder mixture of colloidal silica sol and foaming agent necessarily has an equivalent density to that of the instant claims, resultant from the necessarily equivalent porosity properties. The density would thus be greater than the further minimum values of said claims 35-37.
12. Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Perich et al (US 5766686 A) in view of Scott (US 8235092 B2).
Regarding claim 16, the claim differs from Perich et al as applied above because Perich et al does not teach mixing with a screen mixer. However, it would have been obvious to one of ordinary skill in the art to modify Perich et al in view of Scott in order to use screen agitation in the production process. Scott teaches a method of making an investment molding material by producing a mix comprising a refractory material, colloidal silica, and a foaming agent, and thereafter foaming using a method that can be screen agitation (see column 8, lines 15-20). As can be ascertained, the mixture of Scott is equivalent to that of Perich et al in terms of components, and thus one would have had a reasonable expectation of success in using the foaming method of Scott with said Perich et al process. Doing so would constitute screen mixing. One would have had motivation to use this method in the Perich et al process because Scott specifies that is a known conventional means for forming mixtures of the type taught by Perich et al and Scott, and thus one would have found it advantageous to use to ensure success in preparation of the Perich et al mixture. Each limitation of claim 16 is therefore met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct.
13. Claim 26 is rejected under 35 U.S.C. 103 as being unpatentable over Perich et al (US 5766686 A) in view of Fishwick (US 3413132 A).
Regarding claim 26, the claim differs from Perich et al as applied above because Perich et al does not specify a pH of the foaming agent. However, it would have been obvious to one of ordinary skill in the art to modify Perich et al in view of Fishwick in order to use a foaming agent pH taught therein. Fishwick teaches a foamed ceramic body produce from a slip mixture including a foaming agent. Fishwick teaches that said foaming agent is preferably substantially natural, with a pH of about 6-8 (see column 3, lines 35-40). One of ordinary skill would have had motivation to use the pH taught by Fishwick for the foaming agent component in the Perich et al mixture because the lack of specificity as to this feature in Perich et al would lead one to look to other teachings for an appropriate pH. Fishwick provides such a teaching, and one would have had a reasonable expectation of success in the modification because Perich et al and Fishwick are each drawn to mixtures for forming ceramics that include foaming agents. Each limitation of claim 26 is therefore met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct.
Allowable Subject Matter
14. Claims 14-15 and 30 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The prior art, either alone or in combination, fails to teach or suggest a method of making a foamed colloidal silica binder meeting each limitation of instant claim 12, and wherein the foaming agent is added to a first quantity of aqueous colloidal silica binder and mixed, and thereafter the resultant precursor foamed colloidal silica binder is added to a second quantity of aqueous colloidal silica binder. The prior art also does not teach a method of making a foamed colloidal silica binder meeting each limitation of instant claim 12, and wherein the foaming agent is first added to water to form foamed water and thereafter the foamed water is added to aqueous colloidal silica binder and mixed. The prior art further does not teach or suggest a method of making a foamed colloidal silica binder meeting each limitation of instant claim 12, wherein the formed binder consists only of the foaming agent, water, and colloidal silica particles.
Conclusion
15. Claims 12-13, 16-24, 26-29, and 31-37 are rejected. Claims 14-15 and 30 are objected to.
16. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
17. Any inquiry concerning this communication or earlier communications from the examiner should be directed to NOAH S WIESE whose telephone number is (571)270-3596. The examiner can normally be reached on Monday-Friday, 7:30am-4:30pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Amber Orlando can be reached on 571-270-3149. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/NOAH S WIESE/Primary Examiner, Art Unit 1731
NSW2 September 2026
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