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 .
Claim Interpretation
Regarding Claim(s) 1 and 14 – the phrase “drying the mixed slurry” included the process of removing air from the slurry.
Regarding Claim(s) 1 and 15 – the claimed ranges for respective attributes are inclusive. Example: Claim 1 – nozzle that is less than 40um includes a 40um nozzle; Claim 15 – a diameter between 20 and 30um includes diameters of 20um and 30um.
Regarding Claim 17 –
the term “determining”, as the specification is brought into the claims, maybe performed a human or any other type of device or instrument;
in reference to the phrase “desired range”, any range may be considered desired or undesirable.
Examiner Note: A method is defined as a series of actions (MPEP 2106 (I), i.e., “processes…defines “actions”; inventions that consist of a series of steps or acts to be performed). Thus, since methods are defined by actions, the method is given weight only to the extent that it impacts the method in a manipulative sense. See Ex parte Pfeiffer, 135 USPQ 31, noting “recited structural limitations must affect method in manipulative sense and not amount to mere claiming of a use of a particular structure”. Below is/are a list of claims/limitations that are structural limitations or mere outcomes of the method.
Regarding an aspect of Claim 20 –“ a distance between an extrusion point of the nozzle and the turntable is predetermined to prevent the preform from breaking”, where to prevent the preform from breaking is an outcome of a predetermined distance between the extrusion point of the nozzle and the turntable method, and not a method. As well, to prevent the preform from breaking is a motivation to predetermine the distance.
Claim Objections
Claim(s) 7 and 15 is/are objected to because of the following informalities. The form below is read/Examiner suggestion:
Regarding Claim 7 – The process of claim 4/the method of claim 4.
Regarding Claim 15 - between 20 and 30um / between 20um and 30um.
Claim Rejections - 35 USC § 103
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 pre-AIA 35 U.S.C. 103(a) 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 under pre-AIA 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of pre-AIA 35 U.S.C. 103(c) and potential pre-AIA 35 U.S.C. 102(e), (f) or (g) prior art under pre-AIA 35 U.S.C. 103(a).
Claims 1-2, 4, 6-10, 12-17, 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over NPL
“Material Extrusion of Highly Loaded Silicon Nitride Aqueous Inks for Solid Infilled Structures” by Costakis
et. al. (herein “Costakis”) and in further review of USPGPUB 20220073432A1 by Chandrasekaran (herein
“Chandrasekaran”).
Regarding Claim 1 – Costakis teaches a method for creating a polycrystalline silicon nitride fiber, the method comprising,
classifying the dispersed silicon nitride powder to create a classified fine silicon nitride powder; Page 2 Para. 3 , “…high purity Si3N4 powder with a reported D50…and a surface area…”. Given that the powder has a D50 and a surface area, the powder has been classified.
classifying the dispersed sintering aid to create a classified sintering aid; Page 2 Para. 3, “Alumina (Al2O3) and Yttria (Y2O3) were added as sintering aids…”, “…alumina with a…specified mean particle size…and BET surface area…”, “…and yttria with a…D50…”. Given that the sintering aids have particle size related attributes of mean particle size, surface area, and D50, the sintering aids have been classified.
adding a plasticizer, a binder, and the classified sintering aid to the classified fine silicon nitride powder to define a compound; Page 2 Para. 3 “…by dissolving poly-vinylpyrrodine (PVP) ( the binder) and Master Glenium 7500 …with de-ionized water. Master Glenium 7500…is a water based super plasticizer solution...used as a water reducing dispersant…”, “…once the solution was mixed, sintering aids were added. Next the Si3N4 powder was added…”.
dispersing silicon nitride powder to create a dispersed silicon nitride powder; dispersing a sintering aid to create a dispersed sintering aid; Page 2, Para. 3 “…once the solution was mixed,
sintering aids were added. Next the Si3N4 powder was added in 10g increments…followed by a mixing procedure. The solution and powders were mixed in 1min intervals….this process was repeated until the powders were sufficiently dispersed into an ink”.
mixing the compound to create a mixed slurry; Page 2 Para. 3, “After 20g of Si3N4 powder were added…cylindrical milling media were added to the inks to aid in the mixing process. After the previous listed mixing procedure, the ceramic inks were ball milled…to achieve uniformity and reliable rheological properties”.
drying the mixed slurry to create a material for extrusion; Page 3 Para. 4, “The ceramic inks were loaded into a syringe…to remove these air pockets the syringe was subjected to a planetary mixer…After mixing…a small amount of air and ink were pushed out”.
extruding the material to create a preform; Page 3 Para. 6 Fig. 1c, “…were selected as the nozzles to be used. The inks were deposited layer by layer…various sample geometries were printed..”. Fig 1c illustrates a printed preform.
wherein,
sintering the preform to form the polycrystalline silicon nitride fiber; Page 4 Para. 4, “Pressureless sintering was used to densify…”.
While Costakis uses a nozzle for extruding the silicon nitride material ( a known high-temperature application material) to create the preform (Page 3 Para. 5) and material particle sizes on the order of 1-10um (Page 2 Para. 5), Costakis does not disclose,
the material is extruded through a nozzle that is less than 40 micrometers (um) in diameter;
In an analogous endeavor of 3D printing (extrusion) of ceramic inks through a nozzle using high temperature materials ([0005], [0032] lines 1-5, [0033]), Chandrasekaran discloses direct ink writing of high temperature materials into a filament ([0033] lines 10-13, [0034] lines 4-5). Further, nozzles can be selected to deposit a filament of any size, noting a nozzle size of 200um ([0037 lines 11-12, 17). Nozzle diameter can be considered a result effective variable as the nozzle diameter achieves a recognized result in a relation to the extruded material diameter.
Chandrasekaran discloses the claimed invention except for a nozzle less than 40um in diameter. It would have been obvious to one having ordinary skill in the art at the time of the effective filing date of the claimed invention to optimize the extrusion process for a 40um diameter nozzle, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. One would have been motivated to optimize the extrusion process for a 40um diameter nozzle for the purpose of providing a filament that has a predetermined configuration based on the desired configuration of the printed body, the type of ink being used, as well as the size of the ceramic particles of the ceramic particles in the ink to prevent clogging, as noted Chandrasekaran [0037].
A particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). Further, it is well settled that determination of optimum values of cause effective variables such as these process parameters is within the skill of one practicing in the art. In re Boesch, 205 USPQ 215 (CCPA 1980).
Regarding Claim 2 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein dispersing the silicon nitride powder comprises;
adding a solvent to the silicon nitride powder; Page 2 Para. 3 “…by dissolving poly-vinylpyrrodine (PVP) ( the binder) and Master Glenium 7500 …with de-ionized water (water is a solvent). “…once the solution was mixed, sintering aids were added. Next the Si3N4 powder was added…”.
and after adding the solvent, milling the silicon nitride powder to disperse the silicon nitride
powder within the solvent; Page 2, Para. 3 “… Next the Si3N4 powder was added in 10g increments…followed by a mixing procedure. The solution and powders were mixed in 1min intervals….this process was repeated until the powders were sufficiently dispersed into an ink…”, “…cylindrical milling media were added to the inks to aid in the mixing process…”.
Regarding Claim 4, 6, 7 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of
the limitations of claim 1.
Costakis teaches wherein,
dispersing the sintering aid comprises dispersing one or more metal oxide powders – Claim 4
dispersing metal oxide powder comprises dispersing an aluminum oxide powder – Claim 6
dispersing metal oxide powder comprises dispersing an yttrium oxide powder – Claim 7
Page 2, Para. 5, “Alumina (Al2O3) and Yttria (Y2O3) were added as sintering aids…”, “Master Glenium
7500…is a water based super plasticizer solution...used as a water reducing dispersant…”,
“…once the solution was mixed, sintering aids were added. Next the Si3N4 powder was
added…followed by a mixing procedure… This process was repeated until the powders were
sufficiently dispersed in the ink”.
Regarding Claim 8 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein,
dispersing the sintering aid comprises dispersing a metalloid oxide powder; Page 2 Para. 5,
“...Master Glenium 7500…is a water based super plasticizer solution...used as a water reducing
dispersant…”, “…once the solution was mixed, sintering aids were added. Next the Si3N4 powder
was added…followed by a mixing procedure… This process was repeated until the powders were
sufficiently dispersed in the ink”. Here, dispersing the sintering aids comprises dispersing the
Si3N4 powder. As noted in the point reference NPL document” A review and a fundamental
theory of silicon nitride tribochemistry” by Dante et. al, non-oxide ceramics in air commonly
form oxide films on their surfaces (e.g. silicon nitride) (Page 28 Para.4 and 5) meaning Si3N4
powder in air forms SiO2 on the surface of the Si3N4 powder. Hence, Si3N4 contains SiO2 where Si
is a metalloid and SiO2 is a metalloid oxide powder.
Regarding Claim 9 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein dispersing the sintering aid to create the dispersed sintering aid
comprises,
adding a solvent to the sintering aid ; Page 2 Para. 3 “…by dissolving… Master Glenium 7500
…with de-ionized water. Master Glenium 7500…is a water based super plasticizer solution...used
as a water reducing dispersant…”, “…once the solution was mixed, sintering aids were added.
Here, the solvent is water.
and after adding the solvent, milling the sintering aid to disperse the sintering aid within the
solvent; “Next the Si3N4 powder was added in 10g increments…followed by a mixing
procedure. The solution and powders were mixed in 1min intervals….this process was repeated
until the powders were sufficiently dispersed into an ink…”, “…cylindrical milling media were
added to the inks to aid in the mixing process”. Here, the cylindrical milling media were adding
to the mixing process that was repeated to disperse the all the powders, which includes the
sintering aids into the ink.
Regarding Claim 10 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein dispersing the sintering aid to create the dispersed sintering aid comprises,
combining a first sintering aid and a second sintering aid to create a combined sintering aid;
adding a solvent to the combined sintering aid;
and after adding the solvent, milling the combined sintering aid to disperse the combined sintering aid in the solvent.
Page 2 Para. 3 “…by dissolving… Master Glenium 7500 …with de-ionized water. Master Glenium
7500…is a water based super plasticizer solution...used as a water reducing dispersant…”, “…once
the solution was mixed, sintering aids were added. Here the sintering aids (alumina and yttria) were
added to the solution. Hence the sintering aids were combined in the solution which contains the
solvent water, to create a combined sintering aid; “Next the Si3N4 powder was added in 10g
increments…followed by a mixing procedure. The solution and powders were mixed in 1min
intervals….this process was repeated until the powders were sufficiently dispersed into an ink…”,
“…cylindrical milling media were added to the inks to aid in the mixing process”. Here, the
cylindrical milling media were adding to the mixing process that was repeated to disperse the all the
powders, which includes the combined sintering aid.
Regarding Claim 15 and 16 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all
of the limitations of claim 1.
While Costakis uses a nozzle for extruding the silicon nitride material ( a known high-temperature
application material) to create the preform (Page 3 Para. 5) and material particle sizes on the order of 1-
10um (Page 2 Para. 5), Costakis does not disclose extruding the material to create the preform
comprises,
extruding the material through a nozzle having a diameter between 20 and 30um;
extruding the material through a nozzle having a diameter of 20um.
Chandrasekaran discloses 3D printing (extrusion) of ceramic inks through a nozzle using high
temperature materials ([0005], [0032] lines 1-5, [0033]), via direct ink writing into a filament ([0033]
lines 10-13, [0034] lines 4-5). Further, nozzles can be selected to deposit a filament of any size, noting a
nozzle size of 200um ([0037 lines 11-12, 17). Nozzle diameter can be considered a result effective
variable as the nozzle diameter achieves a recognized result in a relation to the extruded material
diameter.
Chandrasekaran discloses the claimed invention except for a nozzle between 20 and 30um and a nozzle
of 20um in diameter. It would have been obvious to one having ordinary skill in the art at the time of
the effective filing date of the claimed invention to optimize the extrusion process for 20um to 30um
nozzle diameters, inclusive, since it has been held that discovering an optimum value of a result effective
variable involves only routine skill in the art. One would have been motivated to optimize the extrusion
process for 20um to 30um nozzle diameters, inclusive, for the purpose of providing a filament that has a
predetermined configuration based on the desired configuration of the printed body, the type of ink
being used, as well as the size of the ceramic particles of the ceramic particles in the ink to prevent
clogging, as noted Chandrasekaran [0037]. A particular parameter must first be recognized as a result-
effective variable, i.e., a variable which achieves a recognized result, before the determination of the
optimum or workable ranges of said variable might be characterized as routine experimentation, In re
Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). Further, it is well settled that determination of
optimum values of cause effective variables such as these process parameters is within the skill of one
practicing in the art. In re Boesch, 205 USPQ 215 (CCPA 1980).
Regarding Claim 17 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein further comprising,
determining whether a porosity of the polycrystalline silicon nitride fiber is within a desired
range; Page 8, Para. 4, Page 4 Para. 7, “The average calculated densities…were 95.3% TD and
94.9% TD (theoretical density). With the desire for any sintered material to be fully dense
(100%) not fully dense indicates there is porosity. “ A Zeiss Xradia 620 was used to perform x-
ray tomography…to observe and quantify porosity in the material. In order to quantify
porosity…a high-resolution scan…was conducted…using Dragonfly from ORS software in order to
quantify the porosity within the scans”.
and in response to the porosity being outside the desired range, sintering the polycrystalline
silicon nitride fiber in a hot isostatic press; Page 10 Para. 1 , “ “…it may be possible to
alleviate a majority of this porosity through pressure assisted sintering processes such as HIP
(hot isostatic pressing) or elevated pressure sintering”.
Regarding Claim 19 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein extruding the material to create the preform comprises,
drying the extruded material with a dryer apparatus to create the preform; Page 7 Para. 7, “…a
chamber with a set elevated humidity was used…so that the samples could completely dry in a
controlled manner.”
While Costakis teaches disposing the preform on work surface, Costakis fails to disclose,
and disposing the preform on a turntable surface prior to the preform being sintered;
Chandrasekaran further teaches the print platform can be configured to move the work surface so that relative motion between the nozzle and work surface can be provided. Further the print platform can be configured to translate the work surface in X, Y, X directions and can be configured to rotate the work surface about any of the X, Y Z axis [0039]. Incorporating movement, in this case rotation, of a platform in a process is common industrial practice. A person of ordinary skill has good reason to pursue the known option within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense." KSR int'l Co. v. Teleflex Inc., 127 S.Ct. 1727,82 USPQ2d 1385 (2007). Further, greater degrees of freedom in a process can lead to efficiency.
It has been repeatedly held that an implicit motivation to combine exists
not only when a suggestion may be gleaned from the prior art as a whole, but when the ‘improvement’
is technology-independent and the combination of references results in a product or process that is
more desirable, for example because it is stronger, cheaper, cleaner, faster, lighter, smaller, more
durable, or more efficient. And because the desire to enhance commercial opportunities by improving a
product or process is universal—and even common-sensical—we have held that there exists in these
situations a motivation to combine prior art references even absent any hint of suggestion in the
references themselves. In re Sernaker, 702 F.2d 989, 994-95, 217 USPQ 1, 5-6 (Fed. Cir. 1983); See
also, Dystar Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick, 464 F.3d 1356, 1368, 80 USPQ2d
1641, 1651 (Fed. Cir. 2006).
Claim 3, 11, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Costakis et. al in
further view of Chandrasekaran and in further view of WO8807400A1 (English language translation of
the Description and provided herewith and referenced herein) by Novich et. al. (herein “Novich”).
Regarding Claim 3 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
While Costakis discloses the use of purchased and classified silicon nitride powder (Page 2 Para. 5),
Costakis does not disclose a classification method of the silicon nitride powder, such that,
classifying the dispersed silicon nitride powder comprises using a sedimentation method.
In an analogous endeavor of classifying ceramic powders for high performance ceramic parts (line 10, 22, 28), where the powders can be oxides of alumina, cordierite and SiALONS (lines 284-286), Novich teaches classifying ceramic powders can be accomplished through dispersion sedimentation (line 40) and can be expedited with centrifugal sedimentation (line 59) with Example 5 classifying SiAlON (Silicon Aluminum Oxynitride, an alloy of Silicon Nitride) (line 418).
Novich discloses the claimed invention except for sedimentation/classification of silicon nitride . It would have been obvious to one having ordinary skill in the art at the time of the effective filing date of the claimed invention to use the sedimentation process of Novich for the purchased silicon nitride powder of Costakis, as one would be motivated to do so for the purpose of producing narrow particle size ranges to support, orderly particle packing of green bodies, lower sintering temperatures, and reduced sintering shrinkage variability as noted by Novich (lines 33-36).
Regarding Claim 11 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
While Costakis discloses the use of purchased and classified alumina oxide and yttria oxide (Page 2 Para.
5), Costakis does not disclose a classification method of the sintering aid, such that,
the classified sintering aid comprises classifying the dispersed sintering aid with a
sedimentation method.
Novich further teaches that alumina (aluminum oxide) can classified in Example 4 (same classification process used for silicon nitride in Claim 3). It would have been obvious to one having ordinary skill in the art at the time of the effective filing date of the claimed invention to use the sedimentation process of Novich for the purchased aluminum oxide powder of Costakis, as one would be motivated to do so for the purpose of producing narrow particle size ranges to support, orderly particle packing of green bodies, lower sintering temperatures, and reduced sintering shrinkage variability as noted by Novich (lines 33-36).
Regarding Claim 18 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches wherein classifying the dispersed silicon nitride powder to create classified fine
silicon nitride powder comprises,
separating particles suspended in a supernatant from a liquid of the supernatant to create the
classified fine silicon nitride powder;
Novich cites, in general, a supernatant that contains particles for classifying (lines 241-244).
Further, Novich teaches classifying ceramic powders can be accomplished through dispersion sedimentation (line 40) and can be expedited with centrifugal sedimentation (line 59) with Example 5 classifying SiAlON (Silicon Aluminum Oxynitride, an alloy of Silicon Nitride) (line 418). Example 5 is processed per Example 4 (line 418) in a staged classification process using one residence volume of water and dispersant, where each classification stage removes particles from the water (lines 390-409). Novich discloses the claimed invention except for classifying silicon nitride . It would have been obvious to one having ordinary skill in the art at the time of the effective filing date of the claimed invention to use the particle separating process a supernatant of Novich for the purchased silicon nitride powder of Costakis, as one would be motivated to do so for the purpose being able to provide a well dispersed feed slurry that does not contain agglomerates in order for proper classification to be performed, as noted by Novich (lines 238-244, 320-322).
Claim 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Costakis et. al in further view of
Chandrasekaran and further view of U.S. Patent 4,552,851 by Hsieh (herein “Hsieh”).
Regarding Claim 5 - Costakis and Chandrasekaran in the rejection of claim 4 above teaches all of the
limitations of claim 4.
While Costakis teaches the addition of aluminum oxide powder and yttrium oxide powder, Costakis
does not disclose wherein dispersing the one or more metal oxide powders comprises,
dispersing an yttrium aluminum garnet powder;
In a similar endeavor of making high density silicon nitride sintered bodies (Col 2 lines 12-15), Hsieh
teaches the addition of an yttrium aluminum compound in silicon nitride compositions (Col 1 lines 27-
28, Col 2 lines 12-13). It would have been obvious to one of ordinary skill in the art at the time of the
effective filing date of the claimed invention to add an yttrium aluminum compound per Hsieh to the
method Costakis, as one would be motivated to do so for the purposes of eliminating adding yttrium
oxide and aluminum oxide separately, where yttrium oxide could react with the silicon of the silicon
nitride during processing resulting in a nonhomogeneous product, as noted by Hsieh (Col 1 lines 15-20).
Claim 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Costakis et. al in
further view of Chandrasekaran and in further view of WO2022107038A1 (English language translation
of the Description and provided herewith and referenced herein) by Daub et. al. (herein “Daub”).
Claims 12 and 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Costakis et. al in
further view of Chandrasekaran and in further view of NPL evidential reference “Master Builders Safety
Data Sheet MasterGlenium 7500”.
Regarding Claim 12 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all
of the limitations of claim 1.
Costakis teaches wherein adding the plasticizer, the binder, and the classified sintering aid to the
classified fine silicon nitride powder to define the compound comprises,
adding at most two parts of the classified sintering aid to at least eight parts of the classified
fine silicon nitride powder by weight –
Page 2, Table 1 – contains volume % of silicon nitride, alumina and yttria (sintering aids) Master Glenium
7500 (plasticizer) and Polyvinylpyrrolidone ( binder). A PHOSITA can convert vol% to wt% and then to
parts. As it is unknown the molecular weight of Master Glenium 7500, evidential reference Master
Glenium 7500 Safety Data sheet lists 1.049g/cm3 as the density, which will be used for calculation. See
Table 10 summary below:
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Therefore, there are 6.93 parts parts of sintering aid added to 68.04 parts of Si3N4 powder. Reducing,
6.93/68.04 = 1 part sintering aid to 9.82 parts (which is at least 8 parts) Si3N4 powder.
Regarding Claim 13 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all
of the limitations of claim 1.
adding at most five parts by weight of the plasticizer and the binder combined so that a resulting
compound contains at most five parts plasticizer and binder, at most two parts classified
sintering aid, and at least eight parts of the classified fine silicon nitride powder by weight.
Page 2, Table 1 – contains volume % of silicon nitride, alumina and yttria (sintering aids) Master Glenium
7500 (plasticizer) and Polyvinylpyrrolidone ( binder). A PHOSITA can convert vol% to wt% and then to
parts. As it is unknown the molecular weight of Master Glenium 7500, evidential reference Master
Glenium 7500 Safety Data sheet lists 1.049g/cm3 as the density, which will be used for calculation. See
Table 10 summary above.
Therefore, plasticizer and binder provide 4.61 parts to 68.04 parts of Si3N4 powder. Reducing,
4.61/68.04 = 1 part plasticizer and binder (which is at most 5) to 14.75 parts (which is at least 8 parts)
Si3N4 powder. To reiterate from Claim 12,
There are 6.93 parts of sintering aid added to 68.04 parts of Si3N4 powder. Reducing,
6.93/68.04 = 1 part sintering aid to 9.82 parts (which is at least 8 parts) Si3N4 powder.
Regarding Claim 14 - Costakis and Chandrasekaran in the rejection of claim 1 above teach all of the
limitations of claim 1.
Costakis teaches process where the ceramic inks were loaded into a syringe and tapped (agitation) to
release air where the tapping process was effective at removing large pockets of air, and further,
removing smaller air pockets, the syringe was subjected to a planetary mixer (agitation) (Page 3 Para. 4).
While Costakis teaches use of a mixer to remove air from the ceramic inks, Costakis does not disclose,
drying the mixed slurry comprises agitating the mixed slurry under vacuum;
In a similar endeavor of making a silicon nitride ink composition for 3D writing (lines 82, 566), where the
ink composition includes alumina, yttria, binder/additive and water(lines 569-576, 580-581), Daub
discloses the mixing procedure (same as Example 1) was performed “under low pressure of 800mbar”
(line 579), where it is also noted as “a vacuum of 800mbar” for a similar mixing process (lines
616-617). It would have been obvious to one having ordinary skill in the art at the time of the effective
filing date of the claimed invention to use the vacuum mixing process of Daub in the method Costakis as
one would be motivated to do so for the purpose of optimizing homogeneity of the ink to make it
suitable for 3D printing, as noted by Daub (lines 578-579).
Claim 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Costakis et. al in
further view of Chandrasekaran and in further view of NPL “Additive Manufacturing of Dense Ceramic
Parts via Direct Ink Writing of Aqueous Alumina Suspensions” by Rueschhoff et. al. (herein
“Rueschhoff”).
Regarding Claim 20 - Costakis and Chandrasekaran in the rejection of claim 19 above teach
all of the limitations of claim 19.
While Costakis discloses optimized printing parameters including layer height (Page 3 Table 2), and it
would seem reasonable to a PHOSITA that the distance between the extrusion nozzle and the turntable
should be set at a value, Costakis nor the combination discloses,
a distance between an extrusion point of the nozzle and the turntable is predetermined to prevent the preform from breaking;
In an analogous endeavor of direct ink writing of an aqueous alumina suspension containing water, a binder and a dispersant and ball milling the mix to achieve optimized rheological properties (Page 822 Para. 3), Rueschhoff discloses a set of direct ink printing variables including slice height, which is the height between the syringe tip and the build platform (Page 824 Table II.) It would have been obvious to one of ordinary skill in the art at the time of the effective filing date of the claimed invention to set a distance between syringe tip and build platform per Rueschhoff in the method of the combination, as one would be motivated to do so for the purposes of achieving, along with the path width setting, maximum shape retention of the filament, as noted by Rueschhoff (Page 824, Para.1).
Double Patenting
A rejection based on double patenting of the “same invention” type finds its support in the language of 35 U.S.C. 101 which states that “whoever invents or discovers any new and useful process... may obtain a patent therefor...” (Emphasis added). Thus, the term “same invention,” in this context, means an invention drawn to identical subject matter. See Miller v. Eagle Mfg. Co., 151 U.S. 186 (1894); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Ockert, 245 F.2d 467, 114 USPQ 330 (CCPA 1957).
A statutory type (35 U.S.C. 101) double patenting rejection can be overcome by canceling or amending the claims that are directed to the same invention so they are no longer coextensive in scope. The filing of a terminal disclaimer cannot overcome a double patenting rejection based upon 35 U.S.C. 101.
Claims 1-18 are provisionally rejected under 35 U.S.C. 101 as claiming the same invention as in that of copending Application No. USPGPUB 20250243123A1. This is a provisional statutory double patenting rejection since the claims directed to the same invention have not in fact been patented.
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Conclusion
The prior art made of record and not relied upon is considered pertinent to the applicant’s disclosure.
Quadir (U.S. Patent 5,209,885) – teaches (Abstract) a method to prepare a water-based silicon nitride powder extrusion mixture that can be dried and sintered. Further, included in the method are added sintering aids, a drying apparatus, pressureless sintering, and hot isostatic pressing.
Komeya et. al. ( U.S. Patent 4,693, 857) teaches (Abstract) a method to prepare a silicon nitride slurry mixture including sintering aids.
Smith (U.S. Patent 4,350,771) teaches (Abstract) forming silicon nitride polycrystalline bodies that include yttria and silicon dioxide. Further, a method of forming a slurry that includes ball milling.
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/CHRISTOPHER PAUL DAIGLER/ Examiner, Art Unit 1741
/JODI C FRANKLIN/Primary Examiner, Art Unit 1741
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