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 .
Election/Restrictions
Applicant's election with traverse of claims 11-15 in the reply filed on 01/16/2026 is acknowledged. The traversal is on the ground(s) that the method of making the coating according to claim 1 could not be made according to the alternative process as suggested in the restriction requirement mailed on 11/20/2025 because a eutectic mixture could not be made. This is not found persuasive because the provided alternative process of making involves making the rare earth disilicate particles dispersed in a eutectic phase which may also be provided in particulate form. The materials would be provided in an organic coating which can be applied to the surface of the substrate and would therefore not require the sintering step. This would also apply to the distinctness between groups I and III in view of the proposed different processes.
With respect to the burden search, a burden exists for at least the reasons set forth in the restriction requirement mailed on 11/20/2025.
The requirement is still deemed proper and is therefore made FINAL.
Claims 1-10 and 16-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 11, 13 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Pujari et al. (U.S. App. Pub. No. 2012/0315492) in view of Lee et al. (U.S. Pat. No. 11,325,869).
Regarding claim 11, Pujari et al. teaches an environmental barrier coating formed on a silicon carbide/silicon nitride substrate (i.e. a ceramic substrate). (Abstract). The environmental barrier coating includes a first layer and second layer which independently include a mixture of rare earth silicate and cordierite. (Abstract). The rare earth silicate is in the form of particles mixed with the cordierite. (par. [0031]). The content of rare earth disilicate is at least 50 percent by weight and the cordierite is at least 6 percent (par. [0024]-[0025]) which would mean that the relative ratio thereof is 8.3:1 or more, overlapping with the presently claimed range As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). The powders are further densified by sintering the particle compositions together. (par. [0034]).
Pujari et al. does not disclose the presence of an amorphous eutectic phase of rare earth disilicate and cordierite comprising rare earth disilicate particles dispersed therein.
Lee et al. teaches an environmental barrier composition made from a slurry of ceramic material including a mullite-based coat and a rare earth disilicate based bond coat. (Abstract). Lee et al. teaches that the rare earth disilicate coating may be densified by a liquid phase sintering process which fills the gaps between the particles of the coating material. (col. 6, lines 43-62). Lee et al. further teaches that the sintering causes the rare earth disilicate, sintering aid and mullite (the other component present in the coating) to form a liquid phase (i.e. an amorphous eutectic mixture).
It would have been obvious to one of ordinary skill in the art to sinter the environmental barrier coating composition of Pujari et al. using a liquid phase sintering process as disclosed in Lee et al., thereby forming an amorphous eutectic mixture formed from the rare earth disilicate and cordierite included in the coating composition disclosed in the primary reference.
One of ordinary skill in the art would have found it obvious to use a liquid sintering process as disclosed in Lee et al. in view of the teaching that the process is known for densifying ceramic coatings for environmental barrier compositions. One of ordinary skill in the art would therefore have a reasonable expectation of success that the process would be usable in Pujari et al. to achieve suitable densified ceramic coatings. Furthermore, Lee et al. teaches that the process results in enhanced bonding and performance due to the presence of the liquid phase. (col. 6, lines 50-55).
Regarding claim 13, the substrate coated with the ceramic material coating including cordierite would therefore include cordierite on the surface thereof.
Regarding claim 14, the rare earth disilicate may be formed by using yttrium powders having average particles of less than about 1 micron and
Regarding claim 15, the limitation “a component of an aerospace system” does impart additional structural features to the claim. The claim is therefore rejected for substantially the same reasons as claim 1, above.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Pujari et al. (U.S. App. Pub. No. 2012/0315492) in view of Lee et al. (U.S. Pat. No. 11,325,869), further in view of Olson et al. (U.S. App. Pub. No. 2022/0098122)
Pujari in view of Lee et al. is relied upon as described in the claim rejections above.
Pujari in view of Lee et al. does not disclose two ceramic substrates wherein the high temperature coating is at the interface bonding the two substrates.
Olson et al. teaches a method of pressure sintering an environmental barrier on the surface of a ceramic substrate. (Abstract). Olson et al. teaches that the environmental coating may include a rare earth disilicate (par. [0039]-[0040]) along with a free rare earth oxide, aluminosilicate or alkaline earth aluminosilicate such as cordierite to modify the properties. (par. [0041]). Olson et al. teaches several layered structures ceramic layers (i.e. substrates) wherein the environmental barrier coating is applied at an interface between the layers. (Fig. 11A-11B). Olson et al. teaches that the multilayer embodiment allows for controlled density and porosity of the environmental barrier stack. (par. [0073]).
It would have been obvious to one of ordinary skill in the art to use the environmental barrier coating of Pujari et al. to include multiple layers, thereby creating at least one layer which is at the interface of at least a two-layer stack.
One of ordinary skill in the art would have found it obvious to use multiple coating layers in order to allow for a controlled density and porosity for the environmental coating thereby allowing one of ordinary skill in the art to tune the properties thereof.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Pujari et al. (U.S. App. Pub. No. 2012/0315492) in view of Lee et al. (U.S. Pat. No. 11,325,869), further in view of ‘260 (U.S. App. Pub. No. 2010/0255260)
Pujari in view of Lee et al. is relied upon as described in the claim rejections above.
Pujari in view of Lee et al. does not disclose the diameter of the rare earth disilicate materials.
‘260 teaches a slurry-based coating composition with may include particles of mullite and at least one rare earth silicate. (Abstract and par. [0046]). ‘260 discloses that the average particle diameter of the rare earth disilicate generally lies in the range of 0.1 to 10 micrometers for adjusting the viscosity of the mixture. (par. [0046]).
It would have been obvious to one of ordinary skill in the art to use rare earth disilicate particles having diameters in the range disclosed in ‘260 in the composition of Pujari et al., which overlaps with the presently claimed ranges.
One of ordinary skill in the art would have found it obvious to use particle diameters in the range disclosed in ‘260 in view of the teachings therein that the particle diameter is result effective for controlling the viscosity of the ceramic slurry composition. Furthermore, one of ordinary skill in the art would have a reasonable expectation of success that using particles in the range taught in ‘260 would be effective in forming ceramic coating compositions.
Claims 11, 13 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Sechi et al. (U.S. RE39,120).
Regarding claim 11, Sechi et al. discloses a low thermal expansion ceramic material including a cordierite crystal phase. (Abstract). The material includes a crystalline compound precipitated between the grain boundaries of the cordierite crystal phase including rare earth disilicate particles. (col. 3, lines 36-64). Sechi et al. further teaches that the cordierite phase, precipitated phase and sintering aids are sintered together to form a liquid (i.e. amorphous) phase (col. 3, lines 43-46 and col. 6, lines 36-40). This liquid phase would therefore be equivalent to the claimed eutectic amorphous phase and the crystalline rare earth disilicate particles would be dispersed therein. Sechi et al. further discloses that the coating material is applied onto a ceramic substrate. (col. 5, lines 38-44).
Sechi et al. does not explicitly disclose the relative ratio of the liquid phase to precipitated crystalline compounds. However, the reference discloses that the amount rare earth disilicate materials may be included in amounts of 1-20% by weight (col. 4, lines 10-15) and implies that the liquid phase formed by sintering the cordierite is not an excessive amount given that the material is predominantly in a crystalline phase. (Abstract, col. 3, lines 20-29 and Table 1). It would have been obvious to one of ordinary skill in the art to optimize the relative contents of the rare earth disilicate and liquid phase in the ceramic material disclosed in Sechi et al., given teaching in the reference of the utility of the amorphous phase for improving the sintering property of the composite and that the rare earth disilicate for preventing a drop in thermal expansion while increasing the Young’s modulus of the ceramic material. (col. 3, lines 36-46). "Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456 (CCPA 1955). MPEP 2144.05 (II).
Regarding claim 13, the substrate coated with the ceramic material coating including cordierite would therefore include cordierite on the surface thereof.
Regarding claim 15, the limitation “a component of an aerospace system” does impart additional structural features to the claim. The claim is therefore rejected for substantially the same reasons as claim 1, above.
Claims 11-13 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Olson et al. (U.S. App. Pub. No. 2022/0098122) in view of Lee et al. (U.S. Pat. No. 11,325,869).
Regarding claim 11, Olson et al. teaches a method of pressure sintering an environmental barrier on the surface of a ceramic substrate. (Abstract). Olson et al. teaches that the environmental coating may include a rare earth disilicate (par. [0039]-[0040]) along with a free rare earth oxide, aluminosilicate or alkaline earth aluminosilicate such as cordierite to modify the properties. (par. [0041]). Olson et al. teaches the ceramic materials are pressure together which forms a liquid glass phase in an amount of 0.5-20 parts by weight of the coating composition. (par. [0059]). This liquid glass phase would be equivalent to the amorphous eutectic mixture phase presently claimed, wherein the glass phase would include mixtures of cordierite and rare earth disilicate. The content thereof relative to the remaining composition would cause the ratio of the glass and rare earth disilicate to overlap with the presently claimed range since the rare earth disilicate may be included in amounts of 95% or more. (par. [0039]).
Olson et al. does not disclose explicitly that the liquid glass phase comprises rare earth disilicate particles dispersed therein.
Lee et al. teaches an environmental barrier composition made from a slurry of ceramic material including a mullite-based coat and a rare earth disilicate based bond coat. (Abstract). Lee et al. teaches that the rare earth disilicate coating may be densified by a liquid phase sintering process which fills the gaps between the particles of the coating material. (col. 6, lines 43-62). Lee et al. further teaches that the sintering causes the rare earth disilicate, sintering aid and mullite (the other component present in the coating) to form a liquid phase (i.e. an amorphous eutectic mixture).
It would have been obvious to one of ordinary skill in the art to sinter the environmental barrier coating composition of Pujari et al. using a liquid phase sintering process as disclosed in Lee et al., thereby forming an amorphous eutectic mixture formed from the rare earth disilicate and cordierite included in the coating composition disclosed in the primary reference.
One of ordinary skill in the art would have found it obvious to use a liquid sintering process as disclosed in Lee et al. in view of the teaching that the process is known for densifying ceramic coatings for environmental barrier compositions. One of ordinary skill in the art would therefore have a reasonable expectation of success that the process would be usable in Olson et al. to achieve suitable densified ceramic coatings. Furthermore, Olson et al. teaches that the process results in enhanced bonding and performance due to the presence of the liquid phase. (col. 6, lines 50-55).
Regarding claim 12, Olson et al. teaches several layered structures ceramic layers (i.e. substrates) wherein the environmental barrier coating is applied at an interface between the layers. (Fig. 11A-11B).
Regarding claim 13, the substrate coated with the ceramic material coating including cordierite would therefore include cordierite on the surface thereof.
Regarding claim 14, Olson et al. teaches that the rare earth disilicate particles have an average particles diameter of
Regarding claim 15, the limitation “a component of an aerospace system” does impart additional structural features to the claim. The claim is therefore rejected for substantially the same reasons as claim 1, above.
Claim 14 isrejected under 35 U.S.C. 103 as being unpatentable over Olson et al. (U.S. App. Pub. No. 2022/0098122) in view of Lee et al. (U.S. Pat. No. 11,325,869), further in view of ‘260 (U.S. App. Pub. No. 2010/0255260)
Olson in view of Lee et al. is relied upon as described in the claim rejections above.
Pujari in view of Lee et al. does not disclose the diameter of the rare earth disilicate materials.
‘260 teaches a slurry-based coating composition with may include particles of mullite and at least one rare earth silicate. (Abstract and par. [0046]). ‘260 discloses that the average particle diameter of the rare earth disilicate generally lies in the range of 0.1 to 10 micrometers for adjusting the viscosity of the mixture. (par. [0046]).
It would have been obvious to one of ordinary skill in the art to use rare earth disilicate particles having diameters in the range disclosed in ‘260 in the composition of Olson et al., which overlaps with the presently claimed ranges.
One of ordinary skill in the art would have found it obvious to use particle diameters in the range disclosed in ‘260 in view of the teachings therein that the particle diameter is result effective for controlling the viscosity of the ceramic slurry composition. Furthermore, one of ordinary skill in the art would have a reasonable expectation of success that using particles in the range taught in ‘260 would be effective in forming ceramic coating compositions.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDRE F FERRE whose telephone number is (571)270-5763. The examiner can normally be reached M-F: 8 am to 4 pm ET.
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/ALEXANDRE F FERRE/Primary Examiner, Art Unit 1788 03/06/2026