DETAILED ACTION
The claims 12-20 are pending and presented for the examination.
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
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 07/25/2024 is being considered by the examiner.
Claim Rejections - 35 USC § 112
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.
Claims 12-20 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.
Independent claims 12 and 16 recite that the pressureless sintering step includes “normal pressure sintering or vacuum sintering,” however, normal pressure sintering would seemingly not constitute a pressureless sintering operation. It is therefore unclear what the intended claim coverage would be in situations wherein normal pressure sintering is included in the pressureless sintering, but vacuum sintering is not. Said claims are therefore ambiguous and indefinite under USC 112.
Claims 13-15 and 17-20 are indefinite because they depend from said claims 12 and 16 and include the indefiniteness limitations therein.
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 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Han et al (CN 107721406 A) in view of Kaito et al (US 8703041 B2).
Regarding claim 16, Han et al teaches a method for preparing magnesium aluminate spinel transparent ceramic comprising weighing MgO powder and y-Al2O3 powder in a MgO:Al2O3 molar ratio of 1:1.3, adding 100 ppm and 500 ppm CaO as sintering aids, ball milling to form a slurry and thereafter drying and sieving the slurry, and calcining the sieved powder at 800°C for 6 hours; wherein the thus-produced powder is subjected to forming into a magnesium aluminate spinel ceramic body by dry pressing and cold isostatic pressing; and wherein the ceramic body is subject to bisque firing in an air atmosphere at 800°C for 6 hours, followed by presintering in a vacuum furnace at 1400°C for 6 hours, and thereafter performing hot isostatic pressing at a pressure of 200 MPa at 1600°C for 3 hours. The sintered body is annealed in a muffle furnace at 1200°C for 6 hours.
Thus, Han et al teaches a method wherein a calcium-containing sintering aid is added to a starting powder in an amount meeting the instant claim limitation, and is thereafter subjected to pressureless sintering at a temperature and for a time that fall within the corresponding ranges of the instant claim. Claim 16 differs from Han et al because Han et al teaches a calcium-containing sintering aid that is CaO rather than calcium phosphate. However, it would have been obvious to one of ordinary skill in the art to modify Han et al in view of Kaito et al in order to use said calcium phosphate as the sintering aid. Kaito et al teaches a sintered transparent ceramic used in equivalent applications to those for which the Han et al transparent ceramics are used (i.e. cover windows). Kaito et al teaches that the inventive ceramic is prepared from a starting mixture including a sintering additive that can be calcium phosphate (see column 7, lines 25-30). Kaito et al teaches that said calcium phosphate is a sintering additive option that is used equivalently with calcium oxide (ibid.). This teaching indicates to one of ordinary skill in the art that the calcium oxide taught by Han et al can be used equivalently to calcium phosphate in order to achieve equivalent and expected results. Thus, the choice of a calcium phosphate sintering additive as taught by Kaito et al would be made by such factors as material price and availability. The calcium phosphate of Kaito et al would necessarily be represented by a formula listed in the instant claim, as this list encompasses all forms of calcium phosphate. One would have had a reasonable expectation of success in the modification because Han et al and Kaito et al are each drawn to transparent ceramics used for equivalent purposes. 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.
Regarding claim 17, Han et al teaches that the inventive spinel is produced from a starting mixture having a MgO:Al2O3 molar ratio of 1:1.3.
Regarding claim 18, Han et al teaches that the powder mixture is subjected to forming by a dry pressing, which constitutes a dry molding step.
Regarding claims 19-20, Han et al teaches that the magnesium aluminum spinel ceramic is subsequently subjected to hot isostatic pressing at a pressure of 200 MPa and temperature of 1600°C for 3 hours.
Claims 12-15 are rejected under 35 U.S.C. 103 as being unpatentable over Han et al (CN 107721406 A) in view of Hutzler et al (US 9309156 B2) and Kaito et al (US 8703041 B2).
Regarding claim 12, Han et al teaches a method for preparing magnesium aluminate spinel
transparent ceramic comprising weighing MgO powder and y-Al2O3 powder in a MgO:Al2O3 molar ratio of 1:1.3, adding 100 ppm and 500 ppm CaO as sintering aids, ball milling to form a slurry and thereafter drying and sieving the slurry, and calcining the sieved powder at 800°C for 6 hours; wherein the thus-produced powder is subjected to forming into a magnesium aluminate spinel ceramic body by dry pressing and cold isostatic pressing; and wherein the ceramic body is subject to bisque firing in an air atmosphere at 800°C for 6 hours, followed by presintering in a vacuum furnace at 1400°C for 6 hours, and thereafter performing hot isostatic pressing at a pressure of 200 MPa at 1600°C for 3 hours. The sintered body is annealed in a muffle furnace at 1200°C for 6 hours.
Thus, Han et al teaches a method wherein a calcium-containing sintering aid is added to a starting powder in an amount meeting the instant claim limitation, and is thereafter subjected to pressureless sintering at a temperature and for a time that fall within the corresponding ranges of the instant claim. The claim differs from Han et al because Han et al teaches that the sintering aid is added to the component magnesia and alumina oxides rather than to a spinel powder. However, it would have been obvious to one of ordinary skill in the art to modify Han et al in view of Hutzler et al in order to use magnesium aluminum spinel powder having a chemical formula of MgAl2O4 as the starting component to be sintered. Hutzler et al teaches transparent spinel ceramics and methods of producing the same, wherein an additive of CaO is included (see Abstract). Thus, Hutzler et al teaches a method wherein an equivalent additive is included in the batch to form an equivalently composed magnesium aluminum transparent spinel. Hutzler et al teaches that the production method for said transparent spinel comprises using MgAl2O4 powder as the starting material (see column 10, lines 45-55). One would have had motivation to use said powder as the material to be molded and sintered in the Han et al method because doing so would remove the steps of forming the spinel powder from starting MgO and Al2O3. This would be seen as an advantageous reduction in process complexity, and the teachings of Hutzler et al show that this is possible in a method similar to that of Han et al. As such, this further limitation of the instant claim is taught by the prior art of record.
Claim 12 further differs from Han et al because Han et al teaches a calcium-containing sintering aid that is CaO rather than calcium phosphate. However, it would have been obvious to one of ordinary skill in the art to modify Han et al in view of Kaito et al in order to use said calcium phosphate as the sintering aid. Kaito et al teaches a sintered transparent ceramic used in equivalent applications to those for which the Han et al transparent ceramics are used (i.e. cover windows). Kaito et al teaches that the inventive ceramic is prepared from a starting mixture including a sintering additive that can be calcium phosphate (see column 7, lines 25-30). Kaito et al teaches that said calcium phosphate is a sintering additive option that is used equivalently with calcium oxide (ibid.). This teaching indicates to one of ordinary skill in the art that the calcium oxide taught by Han et al can be used equivalently to calcium phosphate in order to achieve equivalent and expected results. Thus, the choice of a calcium phosphate sintering additive as taught by Kaito et al would be made by such factors as material price and availability. The calcium phosphate of Kaito et al would necessarily be represented by a formula listed in the instant claim, as this list encompasses all forms of calcium phosphate. One would have had a reasonable expectation of success in the modification because Han et al and Kaito et al are each drawn to transparent ceramics used for equivalent purposes. Each limitation of claim 12 is therefore met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct.
Regarding claim 13, Han et al teaches that the powder mixture is subjected to forming by a dry pressing, which constitutes a dry molding step.
Regarding claims 14-15, Han et al teaches that the magnesium aluminum spinel ceramic is subsequently subjected to hot isostatic pressing at a pressure of 200 MPa and temperature of 1600°C for 3 hours.
Conclusion
12. No claim is allowed.
13. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
14. 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
NSW10 September 2026
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