Detailed Office Action
Notice of Pre-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
Request for Continued Examination
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 04/09/2026 has been entered.
Response to Amendments
The amendment filed on 04/09/26 has been entered. Claims 1 – 5, 7, and 9 – 27 remain pending. Claims 14 – 27 remain withdrawn. Claims 1 – 5, 7, and 9 – 13 remain under examination.
Response to Declaration under 1.132
The declaration under 37 CFR 1.132 filed 04/09/26 is insufficient to overcome the rejections of:
Claims 1 – 5, 7, 9 – 11 under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173) in view of Wang (US2020/0346365)
For clarity of the record, the Declarant is a co-inventor of the pending applicant.
The Declarant states and provides references that show that plasma spheroidization results in denser particles. The Declarant states that therefore, an ordinarily skilled artisan would appreciate that particles subjected to plasma spheroidization would be fully dense, pore-free particles. The Examiner acknowledges that plasma spheroidization is a known process that increases the density and sphericity of particles and can be used to reduce internal porosity. However, the declaration fails to provide sufficient factual support that subjecting particles to plasma spheroidization would necessarily result in particles without porosity (internal or external).
As previously stated, the prior art of Enneti states that by controlling the power input to the plasma torch, the degree of spheroidization/densification of the granules can be/was controlled [00109].
Furthermore, Wang (which is relied upon for the porosity disclosure) states that the cemented carbide particles are produced by sintering [0019] and can be further heat treated by plasma densification/spheroidization treatment [0019]. Wang expressly acknowledges that densification treatments can be administered any desired number of times to provide sintered cemented carbide particles with desired apparent densities, tap densities and/or individual particle densities (i.e., porosity) [0019].
Therefore, both the prior arts of Enneti and Wang which are relied upon acknowledge that the plasma spheroidization process can be controlled/tailored to achieve desired particle properties.
Additionally, the instant invention’s specification states that particles have a porosity ranging from 2 – 20 percent [0021] and then further states in [0026] that “The densities and individual particle porosities of the powder compositions disclosed herein can be achieved through one or several sintering processes administered to the particles.”, “Further heat treatment can include plasma densification, such as plasma spheroidization using an RF plasma torch or DC plasma torch.”, and “Further densification treatments can be administered any desired number of times to provide sintered cemented carbide particles desired apparent densities, tap densities and/or individual particle densities” (emphasis added by Examiner). As such, the instant invention’s specification acknowledges that plasma spheroidization can be used in the production of powders of the instant invention, which possess a porosity ranging from 2 – 20%.
Further still, prior art Yang (CN108500281) discloses producing powder for additive manufacturing [0001 of translation]. Yang expressly discloses in the claims [Page 40 – 46] that powders with porosity in a range of 20 – 50% [Page 42] can be produced in a process comprising plasma spheroidization [Page 44]
In view of the foregoing, when all of the evidence is considered, the totality of the rebuttal evidence fails to outweigh the evidence of obviousness.
Claim Rejections – U.S.C. §112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 4 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 4 (which depends on claim 1) limits the D50 from at least 14 µm to 20 µm. This is broader than the range of D50 in claim 1 (at least 12 µm to 18 µm) and therefore, claim 4 fails to further limit the claim.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections – U.S.C. §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 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.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1 – 5, 7, and 9 – 11 are rejected under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173, cited in the IDS of 03/06/23) in view of Wang (US2020/0346365, cited in IDS 03/06/23)
Regarding claim 1 – 3, 9 and 11, Enneti teaches densified spheroidized cemented carbide powders for binder jetting [Title, 0092]. Enneti teaches that the spheroidized cemented carbide particles are produced by sintering and then subjected plasma densification/spheroidization [00107 – 00109], meeting the claimed limitation of sintered cemented carbide particles and the claimed limitation of claim 11 that the particles are substantially spherical.
Enneti teaches that the densified spheroidized particles have tungsten carbide [0078] and a metallic binder phase [0079], of which the metallic binder phase can be cobalt [0082], meeting the claimed limitation of claim 2 of comprising tungsten carbide and the metallic binder comprising cobalt.
Enneti teaches that the densified spheroidized particles have a D90 from about 20 µm to about 40 µm microns, which overlaps with the claimed range of claim 1 and claim 9 [0083].
Enneti teaches that the particles comprise about 10 wt% to about 15 wt% of metallic binder phase [Claim 6, 0079], which overlaps with the claimed range of claim 1 and claim 3.
Enneti teaches that the powder composition has a bulk density (i.e. apparent density) of about 4 to about 8 g/cm3, which overlaps with the claimed range [0084].
Enneti teaches an example in which the D10 is 10.8 µm [Table 1], which lies outside the stated upper bound of 10 µm of the claimed range of claim 1 and a D50 of 18.7 µm, which is outside the claimed range of claim 1 [Table 1].
However, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties."(MPEP 2144.05 I)
Additionally, [0041] of the specification states that all numbers quantities of ingredients are modified by the term “about” and Enneti as well explicitly defines that each term is modified by the term “about” [0021].
Further still, an ordinarily skilled artisan would understand that the D10 and D50 of a powder are smaller than the D90 and Enneti teaches that the D90 can be as small as 10 µm [0083], implying that the D10 of Enneti can be less than 10µm and that the D50 of Enneti can be lower than the 18.7 µm of the example.
Lastly, both Enneti and the claimed invention possess an overlapping apparent/bulk density of about 4 to about 8 g/cm3 [0084] and Enneti explicitly teaches that the powder used can achieve a final sintered body with a porosity classification of A00B00C00 [00102]. Therefore, prima facie one skilled in the art would expect them (the claimed powder and powder of Enneti) to possess the same properties.
Enneti discloses that the cemented carbide powder is subjected to sintering and then plasma densification/spheroidization [00107 – 00109], that during plasma densification/spheroidization the powders are densified by collapsing pores [0086], and that by controlling the power input to the plasma torch, the degree of spheroidization/densification of the granules was controlled [00109]. However, Enneti does not explicitly teach the particle porosity of the densified/spheroidized sintered cemented carbide particles.
Wang teaches a cemented carbide powder composition for additive manufacturing [Title]. Wang teaches that the additive manufacturing can be binder jetting [0008] and cemented carbide particles comprise tungsten carbide [0022] and a metallic binder [0023]. Said cemented carbide particles are produced by sintering the particles [0019] and can be further heat treated by plasma densification/spheroidization treatment [0019]. Furthermore, Wang teaches that the average individual particle porosity is less than 5 vol% [0027], which overlaps with the claimed range. Wang also acknowledges that densification treatments (such as plasma spheroidization/densification) can be administered any desired number of times to provide sintered cemented carbide particles with desired apparent densities, tap densities and/or individual particle densities [0019].
It would have been obvious to one of ordinary skill in the art before the effective filing date to have combined the teachings of Enneti and Wang to achieve the cemented carbide powder of Enneti with the average individual particle porosity of less than 5 vol% taught by Wang. Enneti and Wang are directed to the same field of endeavor of cemented carbide powders with metallic binder for binder jetting. Additionally, both powders of Enneti and Wang can be subjected to sintering and plasma densification/spheroidization and Enneti states that controlling the power input to the plasma torch controls the degree of spheroidization/densification of the granules [00109]. Therefore, an ordinarily skilled artisan would have had a reasonable expectation of success.
Furthermore, both of Enneti and Wang disclose attaining a final sintered body with a porosity classification of A00B00C00 [Enneti, 00102 and Wang, 0031] and as such, selection and application of the porosity range of Wang to the powders of Enneti would achieve predictable results.
In regards to the overlapping ranges taught, it would have been obvious to an ordinarily skilled artisan, before the effective filing date of the claimed invention, to have selected the overlapping portion of the ranges disclosed. Selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05.I).
Regarding claims 4 – 5, Enneti in view of Wang teaches the invention as applied in claim 1. Enneti teaches examples in which the D50 is 18.7 µm [Table 1], which falls outside of the stated range of 14 – 18 µm (claim 4) and 12 – 16 µm (claim 5). However, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties."(MPEP 2144.05 I).
Additionally, as defined in [0041] of the specification, all numbers/quantities of ingredients are modified by the term “about” and Enneti as well explicitly defines that each term is modified by the term “about” [0021].
Further still, an ordinarily skilled artisan would understand that the D10 and D50 of a powder were smaller than the D90 and Enneti teaches that the D90 can be as small as 10 µm [0083], implying that the D50 can be lower than the 18.7 µm of the example.
Lastly, both Enneti and the claimed invention of claim 5 possess an overlapping apparent/bulk density of about 4 to about 8 g/cm3 [0084] and Enneti explicitly teaches that the powder used can achieve a final sintered body with a porosity classification of A00B00C00 [00102]. Therefore, prima facie one skilled in the art would expect them (the claimed powder and powder of Enneti) to possess the same properties.
Regarding claim 7, Enneti in view of Wang teaches the invention as applied in claim 1. Enneti teaches an example in which the D10 is 10.8 µm [Table 1], which falls outside of the stated range of 7 – 9 µm. However, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties."(MPEP 2144.05 I).
Moreover, as defined in [0041] of the specification, all numbers quantities of ingredients are modified by the term “about”. Additionally, Enneti also explicitly defines that each term is modified by the term “about” [0021].
Further still, an ordinarily skilled artisan would understand that the D10 and D50 of a powder were smaller than the D90 and Enneti teaches that the D90 can be as small as 10 µm [0083], implying that the D10 can be less than 10µm.
Lastly, both Enneti and the claimed invention of claim 5 possess an overlapping apparent/bulk density of about 4 to about 8 g/cm3 [0084] and Enneti explicitly teaches that the powder used can achieve a final sintered body with a porosity classification of A00B00C00 [00102]. Therefore, prima facie one skilled in the art would expect them (the claimed powder and powder of Enneti) to possess the same properties.
Regarding claim 10, Enneti in view of Wang teaches the invention as applied in claim 1. Wang teaches that the average individual particle porosity is less than 5 vol% [0027], which overlaps with the claimed range. Selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05.I).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173, cited in the IDS of 03/06/23) in view of Wang (US2020/0346365, cited in IDS 03/06/23), as applied to claim 1 above, in further view of Global Tungsten Powders (“Tungsten Carbide – Cobalt Powder for Binder Jetting Printers”, NPL, 2022)
Regarding claim 5, Enneti in view of Wang teaches the invention as applied in claim 1. Enneti teaches a range for the D90 [0083]. Enneti teaches an example with a D50 of 18.7 µm [Table 1], which lies outside the claimed range, but does not disclose ranges for D50.
Global Tungsten Powders teaches a tungsten carbide – cobalt powder for binder jetting [page 5]. Global Tungsten Powders teaches a powder with a D90 of greater than 20 µm [AM WC702], and wherein the powder also possesses a D50 of 15 – 30 µm, which overlaps with the claimed range, and a D10 of 5 – 15 µm [AM WC702, Page 5].
It would have been obvious to one of ordinary skill in the art before the effective filing date to have taken the powder composition of Enneti as-modified by Wang and controlled the D50 to 15 – 30 µm, respectively, as taught by Global Tungsten Powders. Given that both Enneti and Global Tungsten Powders are directed tungsten carbide powders for binder jetting with an overlapping D10, D50, and D90 size, a person of ordinary skill in the art would have a reasonable expectation of success in combining the teachings of Enneti and Global Tungsten Powders to achieve predictable results.
In regards to the overlapping ranges taught, it would have been obvious to an ordinarily skilled artisan, before the effective filing date of the claimed invention, to have selected the overlapping portion of the ranges disclosed. Selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05.I).
Claims 12 – 13 are rejected under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173, cited in the IDS of 03/06/23) in view of Wang (US2020/0346365, cited in IDS 03/06/23), as applied to claim 1, in further view of Prichard (US2020/0307018)
Regarding claims 12 – 13, Enneti in view of Wang teaches the invention as applied in claim 1. Enneti teaches an apparent density of about 4 to about 8 g/cm3 [0084]. Enneti does not explicitly teach the tap density or Hausner ratio (the ratio of tap density to apparent/bulk density).
Prichard teaches techniques for additive manufacturing [Title], including binder jetting [0004, 0007]. Prichard teaches an embodiment of using sintered cemented carbide particles [0018]. Prichard teaches that the sintered cemented carbide particle contains a metallic binder [0025] and an apparent density of at least 4 g/cm3 [0018]. Prichard teaches that the tap density of sintered cemented carbide particles can be at least 5 g/cm3, which overlaps with the claimed range, and the Hausner ratio can be controlled to a range of 1.1 – 1.5 [0019], which overlaps with the claimed range.
It would have been obvious to one of ordinary skill in the art before the effective filing date to have taken the cemented carbide powder of Enneti as-modified by Wang and controlled the tap density and Hausner ratio to at least 5 g/cm3 and 1.1 – 1.5, respectively, as taught by Prichard. Given that both Enneti and Prichard are directed to sintered cemented carbide powders with metallic binder and similar apparent densities that are used for binder jetting (i.e. same field of endeavor and process), a person of ordinary skill in the art would have had a reasonable expectation of success in combining the teachings of Enneti as-modified by Wang and Prichard to achieve predictable results.
In regards to the overlapping ranges taught, it would have been obvious to an ordinarily skilled artisan, before the effective filing date of the claimed invention, to have selected the overlapping portion of the ranges disclosed. Selection of overlapping portions of ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05.I).
Claims 1 – 5 and 9 – 10 are rejected under 35 U.S.C. 103 as being unpatentable over De Flon (US2019/0211424) in view of Prichard (US2018/0236687)
Regarding claims 1 and 10, De Flon teaches cemented carbide for binder jetting [0041]. The cemented carbide particles have a:
D10 from 1 – 5 µm [0020], which lies outside the claimed range.
D50 from 7 – 15 µm [0019], which overlaps with the claimed range.
D90 from 17 – 30 µm [0018], which overlaps with the claimed range.
A metallic binder is present from 8 – 14 wt% [0022], which overlaps with the claimed range
Particles with an average porosity of 10 – 40% [0013], which overlaps with the claimed ranges of claim 1 and claim 10.
De Flon teaches that the particles are pre-sintered prior to 3D printing at a temperature of 1230°C [0069], which the instant invention describes as light sintering [0036 of the specification]. As such, the powder meets the broadest reasonable interpretation of sintered cemented carbide.
With regards to the D10 of De Flon, while the disclosed range falls outside the explicitly claimed range a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties."(MPEP 2144.05 I). Moreover, In re Brandt, 886 F.3d 1171, 1177, 126 USPQ2d 1079, 1082 (Fed. Cir. 2018)(the court found a prima facie case of obviousness had been made in a predictable art wherein the claimed range of "less than 6 pounds per cubic feet" and the prior art range of "between 6 lbs./ft3 and 25 lbs./ft3" were so mathematically close that the difference between the claimed ranges was virtually negligible absent any showing of unexpected results or criticality”. Lastly, as defined in [0041] of the specification, all numbers quantities of ingredients are modified by the term “about”.
De Flon does not expressly teach the apparent density of the powder.
Prichard teaches techniques for additive manufacturing [Title], including binder jetting [0004, 0019]. Prichard teaches using cemented carbide particles [Abstract], wherein the cemented carbide particle uses a metallic binder [0017] and possess an apparent density of at least 6 g/cm3 [Abstract], which overlaps with the claimed range. The cemented carbide particles can have an average size range of 1 – 100 µm [0015] and the metallic binder can be cobalt [0017] in a range of 0.5 – 15% [Table V]. Prichard teaches that the individual particle density is 80 – 98% theoretical density (porosity 2 – 20%) [0012]
It would have been obvious to one of ordinary skill in the art before the effective filing date to have taken the cemented carbide powder for binder jetting of De Flon and controlled the apparent density to be at least 6 g/cm3, as taught by Prichard. Given that both De Flon and Prichard are directed to cemented carbide powders with metallic binder for binder jetting (i.e. same field of endeavor) with overlapping porosity and particle sizes, a person of ordinary skill in the art would have had a reasonable expectation of success in combining the teachings of De Flon and Prichard to achieve predictable results.
With regards to the overlapping ranges taught, “In the case where the claimed ranges "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)”, absent evidence of criticality or unexpected results (MPEP 2144.05 I). "The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims. . . . In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range." In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (MPEP 2144.05 III A).
Regarding claims 2 – 3, De Flon in view of Prichard teaches the invention as applied in claim 1. De Flon teaches that the metallic binder is present from 8 – 14 wt% [0022], which overlaps with the claimed range. “In the case where the claimed ranges "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)” (MPEP 2144.05 III A). De Flon teaches that the carbide can be tungsten carbide [0052] and the metallic binder can be cobalt [0064], meeting the claimed limitations.
Regarding claims 4 – 5 and 9, De Flon in view of Prichard teaches the invention as applied in claim 1. De Flon teaches that the powder size has a D50 from 7 – 15 µm [0019], which overlaps with the claimed range of claims 4 – 5. De Flon teaches that the powder size has a D90 from 17 – 30 µm [0018], which overlaps with the claimed range. “In the case where the claimed ranges "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)” (MPEP 2144.05 III A).
Response to Arguments
Applicant's amendments have overcome the previous rejection of claims 1 – 5, 7, and 9 – 13 under 35 U.S.C. 103 as being unpatentable over Wolfe (“Coarse Cemented Carbide produced via Binder Jetting 3D Printing”, NPL, 2022) as evidenced by GTP (“Additive Manufacturing”, NPL, 2023), and in further view of Prichard (US2020/0307018) and Global Tungsten Powders (“Tungsten Carbide – Cobalt Powder for Binder Jetting Printers”, NPL, 2022). As such, arguments thereto are considered moot.
Applicant’s arguments directed to the rejections of:
Claims 1 – 5, 7, 9 – 11 under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173) in view of Wang (US2020/0346365)
Claim 5 under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173) in view of Wang (US2020/0346365), as applied to claim 1, in further view of Global Tungsten Powders (“Tungsten Carbide – Cobalt Powder for Binder Jetting Printers”, NPL, 2022)
Claims 12 – 13 under 35 U.S.C. 103 as being unpatentable over Enneti (WO2021/072173) in view of Wang (US2020/0346365), as applied to claim 1, in further view of Prichard (US2020/0307018)
have been full considered but are not persuasive.
Applicant argues that the porosity disclosed by Wang could not be applied to Enneti because Enneti produces the powders by plasma spheroidization and as discussed in the declaration and in the references provided, applying plasma spheroidization would result in fully dense, pore-free particles (page 9 – page 10, top). This is not found persuasive.
As discussed above and provided again here, when all of the evidence is considered the totality of the rebuttal evidence fails to outweigh the evidence of obviousness.
The Examiner acknowledges that plasma spheroidization is a known process that increases the density and sphericity of particles and can be used to reduce internal porosity. However, the preponderance of the evidence does not support that subjecting particles to plasma spheroidization would necessarily result in particles without porosity (internal or external).
As previously stated, the prior art of Enneti states that by controlling the power input to the plasma torch, the degree of spheroidization/densification of the granules can be/was controlled [00109].
Furthermore, Wang (which is relied upon for the porosity disclosure) states that the cemented carbide particles are produced by sintering [0019] and can be further heat treated by plasma densification/spheroidization treatment [0019]. Wang expressly acknowledges that densification treatments can be administered any desired number of times to provide sintered cemented carbide particles with desired apparent densities, tap densities and/or individual particle densities (i.e., porosity) [0019].
Therefore, both the prior arts of Enneti and Wang which are relied upon acknowledge that the plasma spheroidization process can be controlled/tailored to achieve desired particle properties.
Additionally, the instant invention’s specification states that particles have a porosity ranging from 2 – 20 percent [0021] and then further states in [0026] that “The densities and individual particle porosities of the powder compositions disclosed herein can be achieved through one or several sintering processes administered to the particles.”, “Further heat treatment can include plasma densification, such as plasma spheroidization using an RF plasma torch or DC plasma torch.”, and “Further densification treatments can be administered any desired number of times to provide sintered cemented carbide particles desired apparent densities, tap densities and/or individual particle densities” (emphasis added by Examiner). As such, the instant invention’s specification acknowledges that plasma spheroidization can be used in the production of powders of the instant invention, which possess a porosity ranging from 2 – 20%.
Further still, prior art Yang (CN108500281) discloses producing powder for additive manufacturing [0001]. Yang expressly discloses in the claims [Page 40 – 46] that powders with porosity in a range of 20 – 50% [Page 42] can be produced in a process comprising plasma spheroidization [Page 44].
Lastly, applicant asserts that although Wang states plasma spheroidization may be used to prepare the powder composition and that the powder composition has a porosity of less 5 vol%, this does not mean that plasma spheroidized particles could achieve this porosity (page 11). Applicant argues that instead, if plasma spheroidization were used in Wang the particles would be fully dense (Page 11). This is not persuasive. As discussed above, the preponderance of the evidence does not support this assertion. The examiner provides further evidence in Itagaki (NPL, 2019) which discusses the application of plasma treatment to WC-12Co powder to spheroidize it [Abstract]. Itagaki shows in Figure 8 that pores/porosity still exists to an extent in the treated powder. As such, the preponderance of the evidence supports that plasma spheroidization/densification can be controlled to attain a particular porosity, including the porosity range disclosed by Wang. As such, a prima facie case of obviousness exists.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Austin M Pollock whose telephone number is (571)272-5602. The examiner can normally be reached M - F (11 - 8 ET).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sally Merkling can be reached at (571) 272-6297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/AUSTIN POLLOCK/Examiner, Art Unit 1738 /SALLY A MERKLING/SPE, Art Unit 1738
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