DETAILED ACTION
Continued Examination Under 37 CFR 1.114
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 June 4, 2026 has been entered.
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 .
Priority
Priority to PCT/US2020/040413 filed July 1, 2020 is acknowledged. A copy of the WIPO publication WO 2022/005465 is attached.
Claim Status
This Office Action is in response to Applicant’s Remarks and Claim Amendments filed June 4, 2026.
Claims Filing Date
June 4, 2026
Amended
9, 14
New
16, 17
Cancelled
1, 5, 6, 8, 10
Pending
2-4, 7, 9, 11-17
The applicant argues support for the claim 9 and claim 14 amendments in [0063] and support for new claims 16 and 17 in [0065] (p. 5 para. 1).
Response to Remarks filed June 4, 2026
Applicant's arguments filed June 4, 2026 have been fully considered but they are not persuasive.
Storck in view of Grinder, Davis, and Satoh; Grinder in view of Davis
The applicant argues Grinder tests AISI316 (p. 29 Table 1), but does not disclose stainless steel 316L powder (p. 6 para. 2, p. 8 para. 2), where Davis Table 1 discloses SS316N1, N2 and SS316L (p. 6 para. 4), with 316L being a low-carbon version of 316 stainless steel (p. 7 para. 2, p. 8 para. 3) and SS316N1, N2 having a higher nitrogen content (p. 7 para. 3).
Grinder discloses oxidation kinetics of stainless steel powders (1. Introduction para. 10) including austenitic steel powders (2.1 Raw material) AISI316 (Table I). Davis discloses austenitic stainless steel S31600 (p. 6 col. 1 paras. 2-4) with enhanced corrosion resistance where the lower-carbon grade (AISI L) prevents intergranular corrosion (p. 6 col. 2 para. 2), such that it would have been obvious to oxidize 316L austenitic stainless steel powder using the process of Grinder.
The applicant argues new claims 16 and 17 recite preheating for a time period from about 2.5 hours to about 15 hours, but Grinder discloses heating for 2 hours (para. spanning pp. 9-10).
Grinder discloses oxidizing with samples for oxygen analysis taken after 5, 10, 30, 60, and 120 minutes (2.2 Surface oxidation of the powder) with data presented as a function of time in which between about 60 and 120 minutes the oxygen content levels out to a set value (3.1.1 Influence of oxidation time and temperature, Fig. 16). Therefore, in light of the disclosure of Grinder, one of ordinary skill in the art would understand that increasing the oxidation time beyond the tested 120 minutes (2 hours) yields a substantially similar oxygen content to 120 minutes (2 hours) of oxidation.
For the above cited reasons, the rejections of Storck in view of Grinder, Davis, and Satoh and over Grinder in view of Davis are maintained.
New Grounds
In light of claim amendment and upon further consideration new grounds of rejection are made over Storck in view of Takahashi and Satoh as evidenced by Davis and over Takahashi as evidenced by Davis.
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 9, 12, 13, 16, 2-4, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Storck (US 2018/0141120) in view of Grinder (Grinder and Ericsson. Low Temperature Oxidation of Inert-Gas Atomized Steel Powder. Modern Developments in Powder Metallurgy. Swedish Institute for Metals Research. 16 (1985), Vol. Date 1984, 295-327.), Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.), and Satoh (EP 3501692).
Regarding claim 9, Storck discloses a method of three-dimensional printing ([0002], [0005], [0025]), the method comprising:
stainless steel particles with an oxidation (corrosion-resistant) barrier (film) formed on the stainless steel particles ([0025], [0028], [0030], [0033], [0055]-[0056]);
iteratively applying individual build material layers of a particulate build material onto a powder bed, the particulate build material including from about 80 wt% to 100 wt% of the stainless steel particles (binder jetting with 100 wt% because the entirety of the feedstock is the stainless steel particles) ([0008], [0043], [0046]); and
based on a three-dimensional object model, iteratively and selectively applying a binding agent to the individual build material layers to define individually patterned object layers that become adhered to one another to form a layered green body object (binder jetting) ([0008], [0046]).
Storck is silent to forming the oxidation (corrosion-resistant) barrier (film) ([0025], [0028], [0030], [0033], [0055]-[0056]) by the claimed preheating of the stainless steel particles.
Grinder discloses preheating stainless steel particles (AISI 316) (Abstract, 2.1. Raw Material, Table I) to a temperature ranging from about 150°C to about 300°C (250°C) for a time period ranging from about 2 hours to about 15 hours (120 minute, 2 hours) (2.2 Surface oxidation of the powder, 3.1.1 Influence of oxidation time and temperature, Figs. 15, 16, 19, 22, Table III) to form an oxidation barrier (oxidized particle surface) on the stainless steel particles, wherein the stainless steel particles have a D50 (mean) particle size of from about 3 um to about 200 um (about 0.003 mm to about 0.2 mm), and from about 0.02 wt% to about 0.3 wt% (about 200 ppm to about 3000 ppm) of a total weight of the stainless steel particles is the oxidation barrier formed on the stainless steel particles (Table III, Figs. 19, 22).
Feature
Claim 9
Grinder Table III
AISI 304
AISI 304
AISI 316
AISI 316
D50
About 0.003 to about 0.2 mm
0.077 mm
0.054 mm
0.077 mm
0.054 mm
Oxidation Barrier
About 200 ppm to about 3000 ppm
247 ppm
340 ppm
205 ppm
270 ppm
It would have been obvious to one of ordinary skill in the art to for the corrosion-resistant oxide film on the stainless steel powder feedstock of Storck to be formed by the low temperature preheating process of Grinder to form a consistent oxide film where after treatment of about an hour the oxygen content of the stainless steel powder levels off (Grinder Figs. 15-16), providing a predictable amount of oxygen in the stainless steel powder (Grinder 1. Introduction) and corrosion resistance of the underlying stainless steel (Storck [0007], [0033]).
Grinder discloses stainless steel powders (1. Introduction para. 10) including austenitic (2.1 Raw material) AISI 316 stainless steel particles (Table I).
Davis discloses austenitic stainless steel S31600 (p. 6 col. 1 paras. 2-4) has enhanced corrosion resistance and lower-carbon grades (AISI L designation) prevent intergranular corrosion (p. 6 col. 2 para. 2) with a carbon content of 0 to 0.03% (Table 1).
It would have been obvious to one of ordinary skill in the art in the process of Grinder for the AISI 316 austenitic stainless steel powder to be stainless steel 316L particles to prevent intergranular corrosion (Davis p. 6 col. 2 para. 2).
Storck discloses binder jetting ([0008], [0046]), but is silent to the claimed binding agent.
Satoh discloses binder jetting ([0002]-[0004], [0095]-[0101]) where the binding agent (resin) including a binder dispersed in an aqueous liquid vehicle (medium) ([0083]-[0086]), wherein the aqueous liquid vehicle includes an organic co-solvent ([0083]) with a boiling point ranging from about 150 °C to about 300 °C (higher than boiling point of water with a specific example of 1,2-butanediol having a boiling point of 192°C) ([0114]-[0115]).
It would have been obvious to one of ordinary skill in the art in the binder jetting process of Storck to use the binding agent disclosed by Satoh increases the solubility of the resin and produces a high-strength three-dimensional object (Satoh [0112]) that prevents nozzles from drying during standby, clogging, and missing (Satoh [0113]), forming an object with reduced voids and reduced unevenness of voids (Satoh [0009]).
Regarding claim 12, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is 1,2 butanediol (Satoh [0115]).
Regarding claim 13, Grinder discloses the oxidation barrier has an average thickness of from about 3 nm to about 30 nm (surface oxide layer too thin to be detected and was less than 1 micron, 1000 nm) (3.2 Metallographic investigation of the oxide layer). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Further, the limitation of the oxidation barrier average thickness has been considered and determined to recite a property that results from the instantly claimed preheating oxidation process. The prior art discloses a composition (316L stainless steel particles; Grinder 1. Introduction para. 10, 2.1 Raw material, Table I, Davis p. 6 col. 1 paras. 2-4, p. 6 col. 2 para. 2, Table 1) and process (preheating at 250°C for 2 hours, Grinder Fig. 22, Table III) that fall within the scope of the claimed, such that the resulting average thickness of the oxidation barrier being about 3 nm to about 30 nm naturally flows from the disclosure of the prior art.
Regarding claim 16, Grinder discloses oxidizing with samples for oxygen analysis taken after 5, 10, 30, 60, and 120 minutes (2.2 Surface oxidation of the powder) with data presented as a function of time in which between about 60 and 120 minutes the oxygen content levels out to a set value (3.1.1 Influence of oxidation time and temperature, Fig. 16). Therefore, in light of the disclosure of Grinder one of ordinary skill in the art would understand that increasing the oxidation time beyond the tested 120 minutes (2 hours), such as from about 2.5 hours to about 15 hours as claimed, yields a substantially similar oxygen content to 120 minutes (2 hours) of oxidation.
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” MPEP 2144.05(II)(A).
Regarding claim 2, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is a polyol (1,2-butanediol), an oligoglycol, or a lactam (Satoh [0115]).
Regarding claim 3, Storck in Satoh discloses the organic co-solvent (water-soluble solvent) is selected from the group consisting of diols; 1,2 butanediol, 1,2-propanediol, 2,3-butanediol, 1,2-pentanediol, 2-methyl-2,4- pentanediol, 2-methyl-1,3-propanediol, triols, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethylene glycol, triethylene glycol, propylene glycol, tripropylene glycol butyl ether, 2-pyrrolidone, 1-(2- hydroxytheyl)-2-pyrrolidone, and a combination thereof (Satoh [0115]).
Regarding claim 4, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is present in the aqueous liquid vehicle in an amount of from about 5 wt% to about 50 wt% (5 mass% to 60 mass% to improve moisture retaining power of the fabrication liquid and to suppress discharge failure due to progression of drying of the nozzles in the head during standby) (Satoh [0116]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 7, Grinder discloses the oxidation barrier is a layer formed from Fe2O3, Fe3O4/FeO, Cr2O3, Ni2O3, Mn2O3, or a combination thereof on a core of the stainless steel particles (a combination of Cr2O3, Mn2O3, Fe2O3, Fe3O4/FeO) (3.2 Metallographic investigation of the oxide layer, Fig. 28).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Storck (US 2018/0141120) in view of Grinder (Grinder and Ericsson. Low Temperature Oxidation of Inert-Gas Atomized Steel Powder. Modern Developments in Powder Metallurgy. Swedish Institute for Metals Research. 16 (1985), Vol. Date 1984, 295-327.), Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.), and Satoh (EP 3501692), and as applied to claim 9 above, and further in view of Liu (US 2002/0189405).
Regarding claim 11, Storck in view of Satoh discloses heating the layered green body object to a temperature to fuse the layered green body object together and form a fused three-dimensional object (sintering) (Satoh [0095]).
Storck in view of Satoh is silent to a (sintering) temperature of from about 600 °C to about 1,500 °C ([0095]).
Liu discloses heating a layered green body object ([0001], [0011], [0022]-[0023]) to a temperature of from about 600 °C to about 1,500 °C (2000-2400°F, 1093-1316°C) to fuse the layered green body object together and form a fused three-dimensional object ([0013], [0025]).
It would have been obvious to one of ordinary skill in the art in the sintering of Storck in view of Satoh to use a temperature of 2000-2400°F (1093-1316°C), which are typical sintering temperatures for ferrous materials (Liu [0013]), such as stainless steel (Liu [0025]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Claims 14, 15, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Grinder (Grinder and Ericsson. Low Temperature Oxidation of Inert-Gas Atomized Steel Powder. Modern Developments in Powder Metallurgy. Swedish Institute for Metals Research. 16 (1985), Vol. Date 1984, 295-327.) in view of Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.).
Regarding claim 14, Grinder discloses a method of preparing a build material (for powder metallurgical (P/M) production) (Abstract, 1. Introduction), comprising heating stainless steel particles (AISI 304 and AISI 316) to a temperature ranging from about 150 °C to about 300 °C (150°C, 200°C, 250°C, or 300°C) for a time period ranging from about 2 hours to about 15 hours (120 minutes, 2 hours) to form an oxidation barrier (oxidized particle surface) on the stainless steel particles (Abstract, Table I, 2.2 Surface oxidation of the powder, 3.1.1 Influence of oxidation time and temperature, Figs. 15 and 16).
Grinder discloses stainless steel powders (1. Introduction para. 10) including austenitic (2.1 Raw material) AISI 316 stainless steel particles (Table I).
Davis discloses austenitic stainless steels include S31600 (p. 6 col. 1 paras. 2-4) with enhanced corrosion resistance and lower-carbon grades (AISI L designation) to prevent intergranular corrosion (p. 6 col. 2 para. 2) have a carbon content of 0 to 0.03% (Table 1).
It would have been obvious to one of ordinary skill in the art in the process of Grinder for the AISI 316 austenitic stainless steel powder to be stainless steel 316L particles to prevent intergranular corrosion (Davis p. 6 col. 2 para. 2).
The preamble reciting a build material for three-dimensional printing has been evaluated and determined to recite the purpose or intended use of the claimed produced particles. The preamble does not result in a structural difference nor a manipulative difference between the claimed invention and the prior art, such that the prior art build material is capable of performing the intended use of being for three-dimensional printing as recited in the preamble. MPEP 2111.02(II).
Regarding claim 15, Grinder discloses the oxidation barrier formed on the stainless steel particles is from about 0.02 wt% to 0.3 wt% (200 ppm to 3000 ppm) of a total weight of the stainless steel particles (Figs. 15 and 16 annotated below with a horizontal dashed line at 200 ppm (0.02 wt%) and a vertical dashed line at 120 minutes (2 hours) for AISI 304, Fig. 15 left, and AISI 316, Fig. 16 right).
PNG
media_image1.png
913
1246
media_image1.png
Greyscale
Regarding claim 17, Grinder discloses oxidizing with samples for oxygen analysis taken after 5, 10, 30, 60, and 120 minutes (2.2 Surface oxidation of the powder) with data presented as a function of time in which between about 60 and 120 minutes the oxygen content levels out to a set value (3.1.1 Influence of oxidation time and temperature, Fig. 16). Therefore, in light of the disclosure of Grinder one of ordinary skill in the art would understand that increasing the oxidation time beyond the tested 120 minutes (2 hours), such as from about 2.5 hours to about 15 hours as claimed, yields a substantially similar oxygen content to 120 minutes (2 hours) of oxidation.
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” MPEP 2144.05(II)(A).
Claims 9, 12, 13, 16, 2-4, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Storck (US 2018/0141120) in view of Takahashi (Takahashi and Fukuzaki. Improvement of Cleanability of Stainless Steels with Various Surface Chemical Composition by Gaseous Ozone. Journal of The Surface Finishing Society of Japan. (2006) Volume 57, Issue 4. Pages 48-53.) and Satoh (EP 3501692) as evidenced by Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.).
Regarding claim 9, Storck discloses a method of three-dimensional printing ([0002], [0005], [0025]), the method comprising:
stainless steel particles with an oxidation (corrosion-resistant) barrier (film) formed on the stainless steel particles ([0025], [0028], [0030], [0033], [0055]-[0056]);
iteratively applying individual build material layers of a particulate build material onto a powder bed, the particulate build material including from about 80 wt% to 100 wt% of the stainless steel particles (binder jetting with 100 wt% because the entirety of the feedstock is the stainless steel particles) ([0008], [0043], [0046]); and
based on a three-dimensional object model, iteratively and selectively applying a binding agent to the individual build material layers to define individually patterned object layers that become adhered to one another to form a layered green body object (binder jetting) ([0008], [0046]).
Storck is silent to forming the oxidation (corrosion-resistant) barrier (film) ([0025], [0028], [0030], [0033], [0055]-[0056]) by the claimed preheating of the stainless steel particles.
Takahashi discloses preheating (heat-drying) stainless steel particles to a temperature range from about 150°C to about 300°C (150°C) for a time period ranging from about 2 hours to about 15 hours (4 h), wherein the stainless steel particles are stainless steel 316L particles (Takahashi 2.1 Materials and chemicals) having a carbon content ranging from about 0.001 wt% to about 0.03 wt% (0 to 0.03%) (Davis Table 1) and a D50 particle size (mean diameter) of from about 3 um to about 200 um (8 um) (Takahashi 2.1 Materials and chemicals).
It would have been obvious to one of ordinary skill in the art in the process of Storck for the stainless steel particles to be 316L stainless steel that have undergone heat-drying at 150°C for 4 h to remove organic residues from the end the processing operation by routine cleaning and sterilizing operation (Takahashi 1. Introduction para. 1) with an 8 um mean diameter of commercially available (The Nilaco Corp., Tokyo) particles (Takahashi 2.1 Materials and chemicals) . In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
The limitation of the heating being to form an oxidation barrier on the stainless steel particles, wherein from about 0.02 wt% to about 0.3 wt% of a total weight of the stainless steel particles is the oxidation barrier formed on the stainless steel particles has been considered and determined to recite a function, property or characteristic that results from the claimed heating process. The prior art discloses a heating (heat-drying) process with a temperature (150°C) and time (4 h) of 316L stainless steel particles (Takahashi 2.1 Materials and chemicals) that fall within the scope of that claimed, such that the claimed heating being to form an oxidation barrier on the stainless steel particles, wherein from about 0.02 wt% to about 0.3 wt% of a total weight of the stainless steel particles is the oxidation barrier formed on the stainless steel particles naturally flows from the disclosure of the prior art.
Storck discloses binder jetting ([0008], [0046]), but is silent to the claimed binding agent.
Satoh discloses binder jetting ([0002]-[0004], [0095]-[0101]) where the binding agent (resin) including a binder dispersed in an aqueous liquid vehicle (medium) ([0083]-[0086]), wherein the aqueous liquid vehicle includes an organic co-solvent ([0083]) with a boiling point ranging from about 150 °C to about 300 °C (higher than boiling point of water with a specific example of 1,2-butanediol having a boiling point of 192°C) ([0114]-[0115]).
It would have been obvious to one of ordinary skill in the art in the binder jetting process of Storck to use the binding agent disclosed by Satoh increases the solubility of the resin and produces a high-strength three-dimensional object (Satoh [0112]) that prevents nozzles from drying during standby, clogging, and missing (Satoh [0113]), forming an object with reduced voids and reduced unevenness of voids (Satoh [0009]).
Regarding claim 12, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is 1,2 butanediol (Satoh [0115]).
Regarding claim 13, the limitation of the oxidation barrier having an average thickness of from about 3 nm to about 30 nm has been considered and determined to recite a function, property or characteristic that results from the claimed heating process. The prior art discloses a heating (heat-drying) process with a temperature (150°C) and time (4 h) of 316L stainless steel particles (Takahashi 2.1 Materials and chemicals; Davis Table 1) that read on that claimed, such that the claimed oxidation barrier having an average thickness of from about 3 nm to about 30 nm naturally flows from the disclosure of the prior art.
Regarding claim 16, Storck in view of Takahashi discloses the time period ranges from about 2.5 hours to about 15 hours (4 h) (Takahashi 2.1 Materials and chemicals).
Regarding claim 2, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is a polyol (1,2-butanediol), an oligoglycol, or a lactam (Satoh [0115]).
Regarding claim 3, Storck in Satoh discloses the organic co-solvent (water-soluble solvent) is selected from the group consisting of diols; 1,2 butanediol, 1,2-propanediol, 2,3-butanediol, 1,2-pentanediol, 2-methyl-2,4- pentanediol, 2-methyl-1,3-propanediol, triols, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethylene glycol, triethylene glycol, propylene glycol, tripropylene glycol butyl ether, 2-pyrrolidone, 1-(2- hydroxytheyl)-2-pyrrolidone, and a combination thereof (Satoh [0115]).
Regarding claim 4, Storck in view of Satoh discloses the organic co-solvent (water-soluble solvent) is present in the aqueous liquid vehicle in an amount of from about 5 wt% to about 50 wt% (5 mass% to 60 mass% to improve moisture retaining power of the fabrication liquid and to suppress discharge failure due to progression of drying of the nozzles in the head during standby) (Satoh [0116]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 7, the limitation of the oxidation barrier being a layer formed from Fe2O3, Fe3O4/FeO, Cr2O3, Ni2O3, Mn2O3, or a combination thereof on a core of the stainless steel particles has been considered and determined to recite a function, property or characteristic that results from the claimed heating process. The prior art discloses a heating (heat-drying) process with a temperature (150°C) and time (4 h) of 316L stainless steel particles (Takahashi 2.1 Materials and chemicals; Davis Table 1) that read on that claimed, such that the claimed oxidation barrier being a layer formed from Fe2O3, Fe3O4/FeO, Cr2O3, Ni2O3, Mn2O3, or a combination thereof on a core of the stainless steel particles naturally flows from the disclosure of the prior art.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Storck (US 2018/0141120) in view of Takahashi (Takahashi and Fukuzaki. Improvement of Cleanability of Stainless Steels with Various Surface Chemical Composition by Gaseous Ozone. Journal of The Surface Finishing Society of Japan. (2006) Volume 57, Issue 4. Pages 48-53.) and Satoh (EP 3501692) as evidenced by Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.) as applied to claim 9 above, and further in view of Liu (US 2002/0189405).
Regarding claim 11, Storck in view of Satoh discloses heating the layered green body object to a temperature to fuse the layered green body object together and form a fused three-dimensional object (sintering) (Satoh [0095]).
Storck in view of Satoh is silent to a (sintering) temperature of from about 600 °C to about 1,500 °C ([0095]).
Liu discloses heating a layered green body object ([0001], [0011], [0022]-[0023]) to a temperature of from about 600 °C to about 1,500 °C (2000-2400°F, 1093-1316°C) to fuse the layered green body object together and form a fused three-dimensional object ([0013], [0025]).
It would have been obvious to one of ordinary skill in the art in the sintering of Storck in view of Satoh to use a temperature of 2000-2400°F (1093-1316°C), which are typical sintering temperatures for ferrous materials (Liu [0013]), such as stainless steel (Liu [0025]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Claims 14, 15, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Takahashi (Takahashi and Fukuzaki. Improvement of Cleanability of Stainless Steels with Various Surface Chemical Composition by Gaseous Ozone. Journal of The Surface Finishing Society of Japan. (2006) Volume 57, Issue 4. Pages 48-53.) as evidenced by Davis (Davis. ASM Specialty Handbook® Stainless Steels. Table 1. General Introduction. ASM International 1994.).
Regarding claim 14, Takahashi discloses a method of preparing (heat-drying) a build material (austenitic stainless steel) (Takahashi Abstract, 1. Introduction para. 1), comprising heating (heat-drying) stainless steel particles to a temperature ranging from about 150 °C to about 300 °C (150°C) for a time period ranging from about 2 hours to about 15 hours (4 h), wherein the stainless steel particles are stainless steel 316L particles (Takahashi 2.1 Materials and chemicals) having a carbon content ranging from about 0.001 wt% to about 0.03 wt% (0 to 0.03%) (Davis Table 1). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
The limitation of the heating being to form an oxidation barrier on the stainless steel particles has been considered and determined to recite a function, property or characteristic that results from the claimed heating process. The prior art discloses a heating (heat-drying) process with a temperature (150°C) and time (4 h) that fall within the scope of that claimed, such that the claimed heating being to form an oxidation barrier on the stainless steel particles naturally flows from the disclosure of the prior art.
The preamble reciting a build material for three-dimensional printing has been evaluated and determined to recite the purpose or intended use of the claimed produced particles. The preamble does not result in a structural difference nor a manipulative difference between the claimed invention and the prior art, such that the prior art build material is capable of performing the intended use of being for three-dimensional printing as recited in the preamble. MPEP 2111.02(II).
Regarding claim 15, the limitation of the oxidation barrier formed on the stainless steel particles being from about 0.02 wt% to 0.3 wt% of a total weight of the stainless steel particles has been considered and determined to recite a function, property or characteristic that results from the claimed heating process. The prior art discloses a heating (heat-drying) process with a temperature (150°C) and time (4 h) (Takahashi 2.1 Materials and chemicals) that fall within the scope of that claimed, such that the claimed oxidation barrier formed on the stainless steel particles being from about 0.02 wt% to 0.3 wt% of a total weight of the stainless steel particles naturally flows from the disclosure of the prior art.
Regarding claim 17, Takahashi discloses the time period ranges from about 2.5 hours to about 15 hours (4h) (2.1 Materials and chemicals).
Related Art
Sera (JPWO2019/167885 with citations from US 2021/0001303)
Sera discloses a stainless steel ([0001]) with a passivation layer having a thickness of 2 nm to 20 nm and a chromium concentration of 0.1 at% to 2.3 at% ([0020], [0031]-[0034]) manufactured by baking the stainless steel at 250°C to 450°C ([0041], [0064]) for a heating time of 0.5 hours to 10 hours ([0065]).
Hatano (JP 2015-001008 machine translation)
Hatano discloses peroxidation of austenitic stainless steel at 300 to 1000°C for 24 hours or less to form a dense oxide film concentrated with Cr, Si, and Mn on the steel surface to improve the uniformity and barrier properties of the oxide film, improving oxidation resistance ([0034]).
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/STEPHANI HILL/Examiner, Art Unit 1735
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