DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Specification
The disclosure is objected to because of the following informalities: In the first lines of examples 1-2, applicants disclose a particle size “from 500 micrometers to less than 45 micrometers” which is unclear in the range it establishes..
Appropriate correction is required.
Claim Interpretation
Mentions towards a “copper sulfate penta-hydrate meta” will be interpreted to mean “copper sulfate penta-hydrate” in claims 5 and 7 as described in the rejections under 35 USC 112 below.
The “iron power particles” in claim 8 will be interpreted as “iron powder” as described in the rejection under 35 USC 112 below.
The term “substantially free of inter-particle sintering” will be interpreted as having 10% contact area or less between particles as described in the rejection of claim 9 under 35 USC 112 below.
In “delubricating the compacted article from the mold” of claim 11, the limitation will be interpreted as the compacted article being already removed from the mold as opposed to delubrication occurring in the mold as described in the rejection under 35 USC 112 below.
Claim 15 will be interpreted as being dependent upon the method of claim 14 and “the CuOFe2O3 magnetic oxide” as “a CuOFe2O3 magnetic oxide” as described in the rejection under 35 USC 112 below.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2, 5-10, and 11-15 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 term “significant degradation” in claim 2 is a relative term which renders the claim indefinite. The term “significant degradation” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Claim 2 describes an insulating material that is characterized by its ability to withstand a thermal treatment (1200-1500F) without "significant degradation". It is unclear what is meant by "significant" or how "significant degradation" is determined to an acceptable or unacceptable limit, thus limiting the claim indefinite. Claim 10 is rejected as being dependent on, and failing to cure the deficiencies of, rejected dependent claim 2.
Regarding claim 5, the phrase “copper sulfate penta-hydrate meta” is unclear in what the compound is. Copper sulfate penta-hydrate is a readily understood compound in the art, but the additional term “meta” renders it unclear as to what the intended meaning is. Therefore, the claim is indefinite. Additionally, examiner recommends changing the wording of the list for the compounds in line 3 starting with “1 to 3 weight percent…” so that choosing from the listed compounds is more clear. Examiner recommends changing the “and/or” to commas for better understanding of what the “at least one of” can be. Claims 6-10 are rejected as being dependent on, and failing to cure the deficiencies of, rejected independent claim 5.
Regarding claim 7, the phrase “copper sulfate penta-hydrate meta” is unclear in what the compound is. Copper sulfate penta-hydrate is a readily understood compound in the art, but the additional term “meta” renders it unclear as to what the intended meaning is. Further, claim 7 states that the “at least one of …” is specifically “copper sulfate penta-hydrate” without the “meta” term. Therefore, the claim is indefinite. Additionally, examiner recommends changing the wording of the list for the compounds in line 3 starting with “1 to 3 weight percent…” so that choosing from the listed compounds is more clear. Examiner recommends changing the “and/or” to commas for better understanding of what the “at least one of” can be. Claim 10 is rejected as being dependent on, and failing to cure the deficiencies of, rejected dependent claim 7.
Claim 8 recites the limitation "the iron power particles" in line 2. There is insufficient antecedent basis for this limitation in the claim. Furthermore, there is a typo as “iron power” opposed to “iron powder”. Claim 5, on which claim 8 depends upon, only mention an iron powder as opposed to powder particles. Thus for examination, claim 8 will be interpreted to mean “iron powder”. Claim 10 is rejected as being dependent on, and failing to cure the deficiencies of, rejected dependent claim 8.
Claim 9 recites the limitation "the iron powder particles" in lines 1 and 2. There is insufficient antecedent basis for this limitation in the claim. Claim 5, on which claim 9 depends upon, only mention an iron powder as opposed to powder particles. Thus, for examination, claim 9 will be interpreted to mean “iron powder”. Claim 10 is rejected as being dependent on, and failing to cure the deficiencies of, rejected dependent claim 9.
The term “substantially free of inter-particle sintering” in claim 9 is a relative term which renders the claim indefinite. The term “substantially free of inter-particle sintering” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. In paragraph [0014] of the instant . Claim 10 is rejected as being dependent on, and failing to cure the deficiencies of, rejected dependent claim 9.
The term “generally comprise” in claim 11 is a relative term which renders the claim indefinite. The term “generally comprise” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Claim 11. Additionally, claim 11 references “delubricating the compacted article from the mold”. It is unclear whether the delubrication occurs while the compacted article is still contained within the mold to release the article from the mold or if the compacted article originates from the mold and was subsequently removed for delubricating. Furthermore, there is no mention of a lubricant being added to the iron powder mixture, so it is unclear how delubrication can occur without presence of a lubricant Claims 12-15 are rejected as being dependent on, and failing to cure the deficiencies of, rejected independent claim 11.
The term “any suitable powder metallurgy lubricant” in claim 12 is a relative term which renders the claim indefinite. The term “any suitable powder metallurgy lubricant” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is unclear what dictates a powder as being “suitable” for a metallurgy lubricant.
The term “significant degrading” in claim 13 is a relative term which renders the claim indefinite. The term “significant degrading” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Claim 13 describes mixing any inorganic compound capable of being thermally treated (1200-1500F) without "significant degrading". It is unclear what is meant by "significant" or how "significant degrading" is determined to an acceptable or unacceptable limit, thus limiting the claim indefinite. Additionally, claim 13 states addition of “at least one of” “magnetic ferrites”. It is unclear if there is one type of magnetic ferrite, at least one of multiple magnetic ferrites simultaneously, or a mixture of different identities of magnetic ferrites applied.
Claim 15 recites the limitation "the steamed treated compacted article" in line 1 and “the CuOFe2O3 magnetic oxide” in line 3. There is insufficient antecedent basis for these limitations in the claim.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Taheri et al (US PGPub 20210104342) in view of Hosokawa et al (US Pat No 9472328).
Regarding claim 1, Taheri teaches a soft magnetic composite (SMC) comprising an iron ferromagnetic material coated with an oxide material. The oxide (paragraph [0055]) includes several listed examples such as CuFe2O4 (CuOFe2O3). In paragraph [0054], Taheri describes that a suitable ferromagnetic material is high purity iron (100 wt% Fe). In example 7, Taheri mixes 4g of coarse Fe powder with 40mg of bulk Fe3O4 (~99 wt% Fe and ~1 wt% Fe3O4). The presence of this oxide layer creates an antiphase domain boundary which may provide an increase in magnetization at the interface between the ferromagnetic and oxide layers (paragraph [0058]). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute the Fe3O4 with CuOFe2O3 as a known alternative oxide source at the disclosed weight percents to generate a SMC. Hosokawa also teaches SMCs that comprise iron with electrically insulating materials. Hosokawa teaches (Col 3, lines 50-60) that a phosphate conversion coating containing trace amounts of nickel can have better heat resistance (thermal stability) and electrical resistivity (a property of insulation, see Fig. 1), thus the SMC can be subjected to heat treatments at higher temperatures and have low core loss (Col 3 lines 20-26). In Col 6 lines 19-22, Hosokawa teaches the coating preferably falls within a range of about 0.01% by mass to 0.8% by mass. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Thus, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to provide an electrically insulating material to the SMC of Taheri, as informed by Hosokawa, to improve the heat resistance and electrical resistivity such that the SMC has lower core loss. Therefore, Taheri and Hosokawa teach the claimed “A soft magnetic composite comprising, based on total weight of the composite: 95 to 99 weight percent iron; 0.1 to 3 weight percent electrically insulating material; 0.5 to 2 weight percent CuOFe2O3; and a balance of incidental impurities.”.
Regarding claim 2, Taheri and Hosokawa teach the SMC of claim 1. Further, Taheri teaches that their SMC is capable of withstanding curing treatments at 500-1200°C. Additionally, Hosokawa teaches a heat treatment step between 500°C-700°C which is possible due to the insulating coating having satisfactory heat resistance (Col 10 lines 50-62). Therefore, it would be expected that the arrival to the SMC as claimed would contain electrically insulating materials capable of withstanding thermal treatments from 648.9-815.56°C (1200-1500°F) without compromising the integrity of the composite. Thus, Taheri and Hosokawa teach the claimed “The composite of claim 1, wherein the electrically insulating material characterized by being capable of withstanding a 1200-1500°F thermal treatment without significant degradation.”.
Regarding claim 3, Taheri and Hosokawa teach the SMC of claim 1. Further, Hosokawa teaches an additional electrically insulating material (Silicone resin coating i.e., a silicon oxide, Col 7 lines 41-67 through Col 8 lines 1-38) to be included with the phosphate conversion coating. The silicone resin coating contributes to formation of Si-O bonds, thereby contributing to better thermal stability and a satisfactorily high electric resistance, when included at 0.05-0.3% by mass (Col 8 lines 25-38). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to further include a silicone resin (a silicon oxide) as an electrically insulating material with the phosphate conversion coating to enhance thermal stability and electric resistance. Thus, Taheri and Hosokawa teach the claimed “The composite of claim 1, wherein the electrically insulating material comprises an electrically insulating oxide”.
Regarding claim 4, Taheri and Hosokawa teach the SMC of claim 1. Hosokawa teaches phosphorous sources that can be phosphoric acid (Col 6, line 33) and specific use throughout examples 1 to 12 and 16 to 20. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to use phosphoric acid as the electrically insulating material of Taheri’s SMC, as informed by Hosokawa, to improve electrical resistivity and heat resistance. Thus, Taheri and Hosokawa teach the claimed “The composite of claim 1, wherein the electrically insulating material comprises at least one of phosphorous acid, phosphorous oxide, and silica oxide”.
Regarding claim 10, Taheri and Hosokawa teach the SMC of claims 1-4. Further, Taheri teaches in paragraph [0095] that their SMC is for use in manufacturing more efficient electric motors that can tolerate high temperatures. It is well known in the art that electric motors possess rotor(s) and stator(s). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to implement the SMC into an electric motor for improved efficiency of the motor and its heat tolerance. Thus, Taheri and Hosokawa teach the claimed “An article comprising the composite of any of the foregoing claims, wherein the article comprises at least one of stators and rotors for electric motors”.
Claims 5 and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al (US PGPub 20160341251) in view of Kim et al (US PGPub 20100181522), Hanejko et al (US PGPub 20070186722), and Wolfgang et al (DE102014017448A1).
Regarding claim 5, Yoshizuka teaches general preparation of an unsintered body (green compact) whereby the metal base material can be any material so long as it can form an oxide film and describes major raw materials as being Fe- and Cu- based metals (paragraphs [0029-31]). In base material examples 1 to 5 (paragraph [0096]), Yoshizuka mixes 2 wt% of Cu powder, 0.7 wt% of a lubricant (the lubricant can be removed during molding process or remain per paragraph [0029]), and remainder Fe powder (97.3 wt%). These powders would be expected to contain incidental impurities as they are not “purified”. Kim similarly prepares a Fe-Cu material which is a soft magnetic composite. In paragraph [0051], Kim describes examples of Fe and Cu sources which include iron nitrate, copper nitrate, and copper sulfate. In all examples and per paragraph [0050], these materials are dissolved in distilled water and thus aqueous (thereby copper sulfate would be copper sulfate penta-hydrate). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute Fe and/or Cu sources with iron and copper nitrate or copper sulfate penta-hydrate as known alternative sources, as informed by Kim, to produce SMCs. Neither Yoshizuka nor Kim disclose use of a hexagonal boron nitride. Hanejko discloses that compacted articles (such as iron based powders) can optionally contain external lubricants such as boron nitride, preferably at 0.01 to 0.5 wt % of the metallurgical powder composition (paragraphs [0070-71]). In composition 7, although the identity of the external lubricant is not disclosed, Hanejko adds it at 0.2 wt%. Regardless, overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed and to add a lubricant such as boron nitride as disclosed with a predictable result of preparing a SMC. Hanejko does not disclose the crystal structure of the boron nitride. Wolfgang discloses use of hexagonal boron nitride as a coolant lubricant, helpful in heat dissipation for metal-based machinery compositions (stainless steel, copper, etc.) and improving tool life. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to use hexagonal boron nitride as a known lubricant to improve heat dissipation of the SMC. Thus, Yoshizuka, Kim, Hanjeko, and Wolfgang teach the claimed “A soft magnetic composite comprising, based on total weight of the composite: 95 to 99 weight percent iron powder; 0.1 to 0.75 weight percent hexagonal boron nitride; 1 to 3 weight percent of at least one of copper sulfate penta-hydrate meta and/or magnesium sulfate penta-hydrate and/or copper nitrate and iron nitrate; and a balance of incidental impurities”.
Regarding claim 7, Yoshizuka, Kim, Hanjeko, and Wolfgang teach the composite of claim 5. Further, as described in the rejection of claim 5 above, Kim teaches copper sulfate penta-hydrate as a known Cu source for SMCs. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute Cu source (Cu powder of Yoshizuka) with copper sulfate penta-hydrate, as informed by Kim, to prepare a SMC. Thus, Yoshizuka, Kim, Hanjeko, and Wolfgang teach the claimed “The composite of claim 5, wherein the at least one of copper sulfate penta-hydrate meta and/or magnesium sulfate penta-hydrate and/or copper nitrate and iron nitrate comprises copper sulfate penta-hydrate”.
Regarding claim 8, Yoshizuka, Kim, Hanjeko, and Wolfgang teach the composite of claim 5. Yoshizuka in paragraph [0025] teaches that the oxide film is subjected to compacting to give a green compact and is formed by a steam treatment between particles of the metal powder constituting the green compact. Further, in paragraph [0030], Yoshizuka discloses that the density of the green compact is such that water vapor can enter throughout the green compact to form an oxide over the particles, thus surrounding them. Therefore, Yoshizuka, Kim, Hanjeko, and Wolfgang teach the claimed “The composite of claim 5 comprising an oxide layer comprising copper oxides and iron oxides and wherein the oxide layer surrounds the iron power particles”.
Regarding claim 9, Yoshizuka, Kim, Hanejko, and Wolfgang teach the composite of claim 5. Yoshizuka teaches in paragraph [0023] that typically, raw material powders are mixed, compacted, and sintered, but their compact is unsintered. The unsintered green compact is the metal base material on which an oxide film is formed (paragraph [0089] and see rejection of claim 8). Thus, it would be expected that the arrival to such a composite would possess an oxide network surrounding the iron powder particles (green compact) and be substantially free of inter-particle sintering as the green compact is unsintered. Therefore, Yoshizuka, Kim, Hanejko, and Wolfgang teach the claimed “The composite of claim 5 characterized by an oxide network surrounding the iron powder particles and being substantially free of inter-particle sintering of the iron powder particles”.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al, Hanejko et al, and Wolfgang et al as applied to claims 5 and 7-9 above, and further in view of Taheri et al.
Yoshizuka, Kim, Hanejko, and Wolfgang teach the SMC of claims 5 and 7-9 but are silent on implementing it into a motor. Taheri teaches in paragraph [0095] that SMCs of similar composition can be used in manufacturing more efficient electric motors that can tolerate high temperatures. It is well known in the art that electric motors possess rotor(s) and stator(s). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to implement the SMC into an electric motor for improved efficiency of the motor and its heat tolerance. Thus, Yoshizuka, Kim, Hanejko, Wolfgang, and Taheri teach the claimed “An article comprising the composite of any of the foregoing claims, wherein the article comprises at least one of stators and rotors for electric motors”.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al, Hanejko et al, and Wolfgang et al as applied to claim 5 above, and further in view of Zeng et al (CN109136605A).
Regarding claim 6, Yoshizuka, Kim, Hanejko, and Wolfgang teach the SMC of claim 5. Hanejko and Wolfgang are silent on providing a boron nitride comprising a size range within 5-10micrometers. Zeng also teaches preparation of composite powders while providing boron nitride as a lubricating phase. Zeng teaches a preferable average particle diameter of 0.05-20 microns. Zeng also describes a “self-propagating process” of powder particle size range on the “basis of the wider” which helps reduce selection difficulty and production cost. Overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed. Further, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to modify the particle size of boron nitride of Wolfgang, as informed by Zeng, to have a sufficiently "wide" diameter, as such a value represents an optimization of a result-effective variable (i.e., size) to reduce selection difficulty and production costs. Thus, Yoshizuka, Kim, Hanejko, Wolfgang, and Zeng satisfy the claimed “The composite of claim 5, wherein the hexagonal boron nitride comprises a size range of 5-10 micrometers in diameter”.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al, Hanejko et al, Wolfgang et al, and Zeng et al as applied to claim 6 above, and further in view of Taheri et al.
Yoshizuka, Kim, Hanejko, Wolfgang, and Zeng teach the SMC of claim 6 but are silent on implementing it into a motor. Taheri teaches in paragraph [0095] that SMCs of similar composition can be used in manufacturing more efficient electric motors that can tolerate high temperatures. It is well known in the art that electric motors possess rotor(s) and stator(s). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to implement the SMC into an electric motor for improved efficiency of the motor and its heat tolerance. Thus, Yoshizuka, Kim, Hanejko, Wolfgang, Zeng and Taheri teach the claimed “An article comprising the composite of any of the foregoing claims, wherein the article comprises at least one of stators and rotors for electric motors”.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al, Hanejko et al, and Wolfgang et al as applied to claim 5 above, and further in view of Aichele et al (US Pat No 6756118).
Yoshizuka, Kim, Hanejko, and Wolfgang teach the composite of claim 5. Yoshizuka teaches in paragraph [0023] that typically, raw material powders are mixed, compacted, and sintered, but their compact is unsintered. Thus, it is expected that the generated composite would be free of inter-particle sintering. Similarly, Aichele teaches preparation of an iron-based SMC with oxide coating/layering. In Col 4 lines 56 through Col 5 line 1, Aichele describes that heating the prepared mixture at approximately 550°C makes it impossible for metal particles to sinter together and thereby to form electrical current paths (see also Col 3 lines 23-31). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to heat the prepared mixture as taught by Aichele such that sintering does not occur, thus reducing current paths between metal particles. Therefore, Yoshizuka, Kim, Hanejko, Wolfgang, and Aichele teach the claimed “The composite of claim 5 characterized by an oxide network surrounding the iron powder particles and being substantially free of inter-particle sintering of the iron powder particles”.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al, Hanejko et al, Wolfgang et al, and Aichele et al as applied to claim 9 above, and further in view of Taheri et al.
Yoshizuka, Kim, Hanejko, Wolfgang, and Aichele teach the SMC of claim 9but are silent on implementing it into a motor. Taheri teaches in paragraph [0095] that SMCs of similar composition can be used in manufacturing more efficient electric motors that can tolerate high temperatures. It is well known in the art that electric motors possess rotor(s) and stator(s). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to implement the SMC into an electric motor for improved efficiency of the motor and its heat tolerance. Thus, Yoshizuka, Kim, Hanejko, Wolfgang, Aichele and Taheri teach the claimed “An article comprising the composite of any of the foregoing claims, wherein the article comprises at least one of stators and rotors for electric motors”.
Claims 11, 12, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al and Aichele et al.
Regarding claim 11, Yoshizuka teaches (see rejection of claim 5 above) mixture of a reduced iron powder with 2wt% Cu powder. Subsequently, the mixture is compacted to make an unsintered green compact (compacted article). Yoshizuka also teaches addition (0.7 wt%) of a lubricant which can be optionally removed (paragraph [0029]) via degreasing step (thus delubrication). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add the optional delubrication step in preparing a compacted article. Kim similarly prepares a Fe-Cu material which is a soft magnetic composite. In paragraph [0051], Kim describes examples of Fe and Cu sources which include iron nitrate, copper nitrate, and copper sulfate. In all examples and per paragraph [0050], these materials are dissolved in distilled water and thus aqueous (thereby copper sulfate would be copper sulfate penta-hydrate). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute Fe and/or Cu sources with iron and copper nitrate or copper sulfate penta-hydrate as known alternative sources, as informed by Kim, to produce SMCs. In Col 4 lines 10-49, Aichele describes in preparation of SMCs that an antitack or lubricating agent can coat the powdered metals in the mixture. In Col 4 lines 56 – Col 5 lines 1-5 (see examples 1-6), Aichele describes heating the mixture in order to pyrolyze the antitack or lubricating agents, thereby removing them or “delubricating”. This pyrolysis step enables the pyrolysis residues of the lubricating agent and the added fine powders to react with one another and/or the surface of metal particles to form the specific chemical compounds of the SMC (see examples 1-6). It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to add the delubrication step via pyrolysis such that the specific chemical compounds of the SMC can properly form. Thus, Yoshizuka, Kim, and Aichele teach the claimed “A method of making a compacted article may generally comprise: high shear mixing an iron powder and 1-5 weight percent, based on the total weight of the iron powder, of an aqueous solution of one of copper sulfate penta-hydrate, copper nitrate and iron nitrate; compacting the mixture in a mold to make the compacted article; and delubricating the compacted article from the mold”.
Regarding claim 12, Yoshizuka, Kim, and Aichele teach the method of claim 11. In paragraph [0029], Yoshizuka discloses the lubricant for compaction can be a powder such as a metal soap or an amide wax. Zinc stearate is a well known metal soap, and ethylene bis stearamide is a well known amide wax to those of ordinary skill in the art. Additionally, Aichele in Col 4 lines 50-55 defines examples of antitack or lubricating agents which can be stearates of zinc. Thus, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the list of disclosed lubricating or antitack agents to arrive at the invention as claimed. Therefore, Yoshizuka, Kim, and Aichele teach the claimed “The method of claim 11 comprising premixing the iron powder and a compaction lubricant comprises at least one of ethylene bis stearamide, zinc stearate, and any suitable powder metallurgy lubricant”.
Regarding claim 14, Yoshizuka, Kim, and Aichele teach the method of claim 11. Furthermore, Yoshizuka discloses in paragraphs [0024-26] a steam treatment step in order to form a triiron tetraoxide (Fe3O4) coating on the surface of the compact which occurs after the delubrication step. For Fe-based metal powder, the temperature of steam treatment is about 400-700°C (752-1292°F), or preferably 400-550°C (752-1022°F). Additionally, in examples 1-5 and 9-12, Yoshizuka steam treats the degreased (delubricated) base material at 500°C or 900°F (550°C or 1022°F in example 9). Thus, Yoshizuka, Kim, and Aichele teach the claimed “The method of claim 11 comprising heating the de-lubricated compacted article via a steam to a temperature of 900-1100°F to form an iron oxide (Fe3O4) layer on the surface of the iron powder”.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al and Aichele et al as applied to claim 11 above, and further in view of Hanejko et al and Wolfgang et al.
Yoshizuka, Kim, and Aichele teach the method of claim 11 as described above. Aichele describes forming an insulating layer around the core particles (paragraphs [0042-44]) whereby the insulating layer can be oxides or inorganic compounds such as a silicon oxide. Aichele is silent on this insulating layer withstanding 1200-1500°F (648.9-815.56°C) and on the amount provided but does disclose the insulating layer is formed by thermally treating the core particle at a temperature ranging from 300-1200°C (paragraph [0057]), thus it would be expected that the insulating layer can withstand such a thermal treatment without degradation. As described in the rejection of claim 5 above, Hanejko and Wolfgang discuss inclusion of a boron nitride (hexagonal in the case of Wolfgang) in the method of making a compacted article. Hanejko discloses that compacted articles (such as iron based powders) can optionally contain external lubricants such as boron nitride, preferably at 0.01 to 0.5 wt % of the metallurgical powder composition (paragraphs [0070-71]). In composition 7, although the identity of the external lubricant is not disclosed, Hanejko adds it at 0.2 wt%. Regardless, overlapping ranges have been held to present a prima facie case of obviousness over the prior art. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to select from the overlapping portion of the range to arrive at the invention as claimed and to add a lubricant such as boron nitride as disclosed with a predictable result of preparing a SMC. Hanejko does not disclose the crystal structure of the boron nitride. Wolfgang discloses use of hexagonal boron nitride as a coolant lubricant, helpful in heat dissipation for metal-based machinery compositions (stainless steel, copper, etc.) and improving tool life. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to use hexagonal boron nitride as a known lubricant to improve heat dissipation of the compacted article. Thus, Yoshizuka, Kim, Aichele, Hanejko, and Wolfgang teach the claimed “The method of claim 11 comprising mixing the iron powder with 0.1-0.75 weight percent, based on the total weight of the iron powder, at least one of hexagonal boron nitride, cubic boron nitride, Fe2O3, magnetic ferrites, silicon dioxide powder and any other inorganic compound capable of withstanding 1200-1500°F thermal treatment without significant degrading”.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshizuka et al in view of Kim et al and Aichele et al as applied to claim 14 above, and further in view of Verma et al (US PGPub 20050019558).
Regarding claim 15, Yoshizuka, Kim, and Aichele teach the method of claim 14 (inclusion of steam treatment step). Yoshizuka is silent on an additional treatment step after steam treatment. Verma also teaches preparation of ferromagnetic composites or compacted articles whereby the ferromagnetic particles can undergo two coating processes (paragraphs [0029], [0033], and [0037]). The first layer is a Fe3O4 conversion coating, and the optional additional coating may comprise a metal oxide (through inclusion of Cu as taught by Yoshizuka, a CuOFe2O3 layer would thus form). Although Verma teaches this coating step prior to compaction, Yoshizuka teaches that oxide layer formation can occur afterwards by a steam and/or thermal treatment. Thus, it would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to substitute the order of steps with a predictable result of coating iron powder with an oxide layer. Regardless, in examples 3-4, Verma teaches coating particles with black oxide (Fe3O4) after compaction and notes that unintentional inclusion of oxygen during a decarburization annealing treatment at 780°C (1436°F) led to formation of insulating oxide mixtures which were exploited for developing materials of high permeability. Additionally, in paragraph [0043], Verma discloses thermal treatment (250-950°C or 482-1742°C) is carried out in an inert atmosphere or a reactive atmosphere such as air (21% O2), suggesting that increasing oxygen can aid in formation of insulating oxide mixtures to increase permeability. It would have been prima facie obvious to one of ordinary skill in the art, as of the effective filing date, to modify oxygen content of air, balancing with in the thermal treatment, as informed by Verma, to form insulating oxide layers, as such an oxygen content (starting with 21%) represents an optimization of a result-effective variable (i.e. concentration) to improve permeability of the compacted article. Thus, Yoshizuka, Kim, Aichele, and Verma teach the claimed “The method of claim 11 comprising heating the steamed treated compacted article in a 25-30% oxygen atmosphere and a balance of nitrogen and/or any other inert gas to a temperature of 1300-1500°F to form the CuOFe2O3 magnetic oxide on the surfaces of the iron powder”.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Kejzelman et al (US Pat No 7153594) describe preparation of iron SMCs with an insulating inorganic oxide coating and lubricant. Da Luz et al (US PGPub 20190228892) describe enriching the surfaces of ferromagnetic composites and coating with oxides. Kim et al (US PGPub 20150015359) describe importance of creating inter-particle boundaries between the iron and oxide components of the SMC. Skarman et al (US PGPub 20090042051) teach a method of preparing SMCs along with steam treatment step. Jansson et al (US Pat No 6348265) teach a SMC comprising iron and a phosphorous-oxygen based coating. Vachon et al (US PGPub 20100224822) teaches thermal treatment in an oxidizing atmosphere.
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/NWFG/Examiner, Art Unit 1759
/MELVIN C. MAYES/Supervisory Patent Examiner, Art Unit 1759
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