RESPONSE TO AMENDMENT
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 .
WITHDRAWN REJECTIONS
The 35 U.S.C. §103 rejections of the claims made of record in the office action mailed on 03/11/2026 have been withdrawn due to Applicant’s amendment in the response filed 06/11/2026.
REJECTIONS
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
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 25-26 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claim 25, the limitation “the high temperature coating is continuous with at least a portion of the cordierite phase of the portion of the ceramic substrate adjacent to the surface of the at least one ceramic substrate” does not have support in the specification as originally filed. The closest feature that the Examiner could find refers to the coating composition being continuous after sintering (Applicant’s specification, par. [0041]). However, there is no disclosure of a continuous structure of cordierite between the coating and the substrate.
Regarding claim 26, the limitation “the rare earth disilicate particles comprises at least 95 percent by weight (wt.%) of the at least one ceramic substrate” does not have support in the specification as originally filed. The specification does not disclose that the substrate includes the rare earth disilicate particles, let alone in an amount of 95 percent by weight as claimed.
Claim 26 is 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.
The limitation “at least 95 percent by weight (wt.%) of the at least one ceramic substrate” is unclear because it appears as though it is the coating composition of claim 11 which contains the rare earth disilicate particles. Are the rare earth disilicate particles in the substrate distinct from those in the coating? For purposes of examination, the examiner is interpreting the limitation as referring the content of rare earth disilicate particles in the coating composition, not the ceramic coating.
Claim Rejections - 35 USC § 103
Claims 11, 15, 21-22 and 25-26 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 (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]).
With respect to the limitation “a portion of the at least one ceramic substrate adjacent to a surface of the at least one ceramic substrate comprises a cordierite phase”, either one of the layers as described in Pujari et al. would also meet the limitation of “at least ceramic substrate” and the other layer being the high temperature coating. The first and the second layers described in Pujari et al. both comprise cordierite (par. [0024] and [0027]) and would therefore satisfy the limitation of “a portion of the at least one ceramic substrate adjacent to a surface of the at least one ceramic substrate comprises a cordierite phase”, as claimed, where the first layer is the substrate and the second is the coating layer or vice versa.
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 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.
Regarding claim 21, the combination of Pujari in view of Lee et al. would result in a composition including rare earth disilicate particles dispersed in a eutectic phase. The limitation “formed by consolidation of cordierite of the cordierite particles”, the method of forming the product is not germane to the issue of patentability of the product itself, unless Applicant presents evidence from which the Examiner could reasonably conclude that the claimed product differs in kind from those of the prior art. MPEP 2113. Given that Lee et al. teaches forming a eutectic mixture of rare earth disilicates and mullite material, it would be obvious to one of ordinary skill in the art to create a eutectic mixture using the rare earth disilicate and cordierite materials in Lee et al. to form a densified ceramic material.
Regarding claim 22, the first and second layers disclosed in contain cordierite in a bulk of the matrix. (par. [0024] and [0027]).
Regarding claim 25, since the cordierite in the first and second layers are adjacent and in contact with one another, the coating composition would be continuous as claimed.
Regarding claim 26, the first layer may comprise “about 6 percent” cordierite (par. [0024]) which would mean the rare earth disilicate would be “about 94” which be sufficient to overlap with the range of “95 percent by weight”. Furthermore, the second layer includes at least 97% weight rare earth discilicate. (par. [0028]).
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.
Claim 23 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 Harris (CA 2,935,952).
Pujari in view Lee et al. is relied upon as described in claims 11 and 14, above.
Pujari in view of Lee et al. does not disclose that the rare earth disilicate particles have a bimodal or trimodal particle size distribution.
Harris teaches a ceramic matrix material which includes a ceramic particle based slurry, including rare earth metal silicate. (Abstract and par. [0013]-[0015]). Harris teaches that the size of the ceramic particles in the slurry may vary and be included in monomodal, bimodal or multimodal distribution. (par. [0015]).
It would have been obvious to one of ordinary skill in the art to select rare earth disilicate particles in the coating composition of Pujari et al. have bimodal or higher particle size distributions.
One of ordinary skill in the art would have found it obvious to include a particle composition having bimodal or higher distributions in order to adjust the porosity and packing density of the coating by allowing smaller particles to fill the voids between larger particles.
Claims 23-24 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 Tang et al. (EP 4 296 249)
Pujari in view Lee et al. is relied upon as described in claims 11 and 14, above.
Pujari in view of Lee et al. does not disclose that the rare earth disilicate particles have a bimodal or trimodal particle size distribution.
Furthermore, Pujari in view of Lee et al. does not disclose the packing factor of the rare earth disilicate particles. “Packing factor” is being interpreted consistent with the broadest reasonable interpretation of the term which refers to the fraction volume of the coating that is occupied by the ceramic particles
Tang et al. teaches an environmental barrier coating composition including an interlayer composition from a slurry applied to the surface of a substrate material. (Abstract and [0047]). Tang et al. teaches that multimodal particle size distributions for ceramic particles allows for improved packing of the particles when the slurry is applied and reduces the capacity for shrinking. (par. [0047]-[0050]). Tang et al. further teaches that the solids load of the composition should be greater than 60% by volume (par. [0052]), which implies a packing factor overlapping with the presently claimed range due to the discouraging the presence of voids or areas that are low in packed ceramic particles, allowing a dense ceramic coating.
It would have been obvious to one of ordinary skill in the art to use a slurry composition of rare earth disilicate particles having a multimodal particle size distribution (i.e. bimodal or higher) and have a solid load of the particle layer of 60% by volume or greater in Pujari et al. as taught in Tang et al.
One of ordinary skill in the art would have found it obvious to use a multimodal particle size distribution and a solid load content of 60% volume or greater in order to form a dense coating composition that would have reduced capacity for shrinkage during sintering or curing, thereby forming an improved ceramic coating.
Claims 11-12, 15, 21-22 and 25-26 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]).
With respect to the limitation “a portion of the at least one ceramic substrate adjacent to a surface of the at least one ceramic substrate comprises a cordierite phase”, Olson et al. teaches etching the surface of the ceramic substrate and pressure sintering the environmental barrier coating onto the surface of the substrate. (par. [0046]-[007]). The environmental barrier coating is applied onto the substrate is the form of a paint, paste or slurry (par. [0053]) and is then place in an isostatic press (HIP) furnace which causes diffusion between the boundaries/voids of the layers (par. [0057]) which causes a portion of the environmental barrier coating to be disposed in the textured surface of the ceramic substrate. (par. [0059]). Therefore, Olson et al. teaches that a portion of the environmental coating, which includes cordierite, is present in a portion of the ceramic substrate adjacent to the surface thereof.
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 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.
Regarding claim 21, the combination of Olson in view of Lee et al. would result in a composition including rare earth disilicate particles dispersed in a eutectic phase. The limitation “formed by consolidation of cordierite of the cordierite particles”, the method of forming the product is not germane to the issue of patentability of the product itself, unless Applicant presents evidence from which the Examiner could reasonably conclude that the claimed product differs in kind from those of the prior art. MPEP 2113. Given that Lee et al. teaches forming a eutectic mixture of rare earth disilicates and mullite material, it would be obvious to one of ordinary skill in the art to create a eutectic mixture using the rare earth disilicate and cordierite materials in Lee et al. to form a densified ceramic material.
Regarding claim 22, since the cordierite phase of the environmental barrier coating infiltrates the ceramic substrate texture surface, the cordierite would be considered a “bulk material” of the substrate.
Regarding claim 24, Olson et al. teaches that the environmental barrier coating has a porosity of less than 20 vol% (par. [0042]), implying a packing ratio of over 80 vol.%, overlapping with the presently claimed range.
Regarding claim 25, the infiltration of the environmental barrier coating into the substrate would result in a continuous cordierite phase joining the substrate and environmental barrier coating.
Regarding claim 26, the environmental barrier coating consists essentially of the rare earth silicate material which means 5% or less of the coating material is not rare earth disilicate (i.e. 95% or more by weight of rare earth silicate as claimed). (par. [0039]).
Claim 14 is 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), 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.
Claims 23-24 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), further in view of Tang et al. (EP 4 296 249)
Olson in view Lee et al. is relied upon as described in claims 11 and 14, above.
Polson in view of Lee et al. does not disclose that the rare earth disilicate particles have a bimodal or trimodal particle size distribution.
Furthermore, Olson in view of Lee et al. does not disclose the packing factor of the rare earth disilicate particles. “Packing factor” is being interpreted consistent with the broadest reasonable interpretation of the term which refers to the fraction volume of the coating that is occupied by the ceramic particles
Tang et al. teaches an environmental barrier coating composition including an interlayer composition from a slurry applied to the surface of a substrate material. (Abstract and [0047]). Tang et al. teaches that multimodal particle size distributions for ceramic particles allows for improved packing of the particles when the slurry is applied and reduces the capacity for shrinking. (par. [0047]-[0050]). Tang et al. further teaches that the solids load of the composition should be greater than 60% by volume (par. [0052]), which implies a packing factor overlapping with the presently claimed range due to the discouraging the presence of voids or areas that are low in packed ceramic particles, allowing a dense ceramic coating.
It would have been obvious to one of ordinary skill in the art to use a slurry composition of rare earth disilicate particles having a multimodal particle size distribution (i.e. bimodal or higher) and have a solid load of the particle layer of 60% by volume or greater in Olson et al. as taught in Tang et al.
One of ordinary skill in the art would have found it obvious to use a multimodal particle size distribution and a solid load content of 60% volume or greater in order to form a dense coating composition that would have reduced capacity for shrinkage during sintering or curing, thereby forming an improved ceramic coating.
ANSWERS TO APPLICANT’S ARGUMENTS
Applicant’s arguments in the response filed 06/11/2026 regarding the 35 U.S.C. §103 rejections made of record in the office action mailed on 03/11/2026 have been considered but are moot due to the new grounds of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/ALEXANDRE F FERRE/Primary Examiner, Art Unit 1788 07/16/2026
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