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 .
Preliminary amendment filed 6/6/2023 is made of record. Claims 3-4, 6, and 8-13 are amended; and claims 1-13 are currently pending in the application.
Information Disclosure Statement
It is noted that US Patent Application Publication (US 2013/0026412 A1) is listed multiple times in different IDS filed on 3/24/2023; 4/11/2025; and 8/14/2025. This reference is considered once and a line is put through the other listing.
Specification
The abstract of the disclosure is objected to because abstract should be in narrative form and generally limited to a single paragraph on a separate sheet within the range of 50 to 150 words. Correction is required. See MPEP § 608.01(b). In the present instance, abstract includes more than one paragraph and more than 150 words.
Claim Rejections - 35 USC § 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 (i.e., changing from AIA to pre-AIA ) 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.
The factual inquiries 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.
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.
Claims 1-6 and 8-16 are rejected under 35 U.S.C. 103 as being unpatentable over Machida et al (US 2013/0026412 A1).
Regarding claims 1, 3, 6, and 16, Machida et al disclose a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of (i) polymerizing an acrylic acid (salt) monomer aqueous solution (i.e., reads on step of polymerizing an aqueous monomer solution to obtain a crosslinked hydrogel polymer in present claim 1; aqueous monomer solution contains an acid group-containing unsaturated monomer as main component in present claim 6; and the crosslinked hydrogel polymer is a crosslinked polymer containing poly(meth)acrylic acid (salt) as a main component in present claim 16); (ii) during or after the step of (i), gel grinding of a hydrogel crosslinked polymer obtained by polymerization (i.e., reads on gel crushing step of crushing the crosslinked hydrogel polymer after the polymerization step to obtain a crosslinked particulate hydrogel polymer in present claim 1); (iii) drying a particulate hydrogen crosslinked polymer obtained by the gel grinding (abstract) which reads on drying step of drying the crosslinked particulate hydrogel polymer to obtain a dried product in present claim 1. The use of gel crushing device is implicit in the step of gel grinding of the hydrogel crosslinked polymer obtained by polymerization in present claim 1. The gel grinding device is a screw extruder that includes a casing 11, a base 12, screw 13 (i.e., reads on the main body in present claim 1), feed opening 14 (i.e., reads on input port), and extrusion opening 16 (paragraphs 0221-0222 and Figure 1) which reads on discharge port in present claim 1. Any type of gel grinding devices are applicable to the gel grinding step including a continuous twin screw extruder (paragraph 0220) which reads on plurality of rotation axis each including a crusher in present claim 1, continuously crushed in present claim 1, and continuous multiaxial kneader in present claim 3. It is the Office’s position that crosslinked hydrogel polymer is continuously put into the gel-crushing device from the input port and continuously taken out from the discharge port is implicit in the use of continuous twin screw extruder comprising an input port and discharge port. The polymer conversion ratio is not less than 93 mol% (paragraph 0235) which overlaps with the polymerization of 90 mass% or more in present claim 1. For the sake of particle diameter control and properties, temperature of the hydrogel before gel grinding is preferably in the range of 600C to 1200C. A gel temperature lower than 400C results in a greater hardness of the resultant hydrogel, thereby making it difficult to control a particle shape and size distribution in grinding (paragraph 0205). The gel grinding means subjecting, to gel grinding, the hydrogel crosslinked polymer obtained in the polymerization step to have weight average particle diameter in a range of 300 microns to 3000 microns (paragraph 0160).
Machida et al are silent with respect to temperature of crusher of the gel-crushing device; and mass average particle diameter as converted to a solid content.
However, regarding temperature of crusher of the gel-crushing device, given that temperature before gel grinding is preferably in a range of 600C to 1200C, and at temperature lower than 400C, hydrogel has greater hardness and makes it difficult to control a particle shape and size distribution in grinding, it would have been obvious to one skilled in art prior to the filing of present application to crush the hydrogel crosslinked polymer by maintaining the temperature above 500C to obtain desired particle shape and size distribution, absent evidence to the contrary.
Regarding mass average particle diameter as converted to a solid content, given that process of preparing the water-absorbing resin powder is substantially similar and the grinding device includes a twin screw extruder with an input port, main body, and discharge port and can be crushed (grind) at temperature higher than 500C, and the obtained particle after grinding has an average particle diameter in a range of 300 microns to 3000 microns, one skilled in art prior to the filing of present application would have a reasonable basis to expect the crosslinked particulate hydrogel polymer discharged from the discharge port to have a mass average particle diameter d1 of 3 mm or less as converted to a solid content, absent evidence to the contrary.
Regarding claim 2, Machida et al teach that for the sake of particle diameter control and properties, temperature of the hydrogel before gel grinding is preferably in the range of 600C to 1200C (paragraph 0205) which overlaps with the gel temperature T1 of 500C or higher in present claim 2. Case law holds that when the range of instant claims and that disclosed in prior art overlap, a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). See MPEP § 2144.05.
Regarding claim 4, Machida et al teach that gel temperature may be retained by heat retaining (paragraph 0205).
Regarding claims 5 and 9, Machida et al teach that for the sake of particle diameter control and properties, temperature of the hydrogel before gel grinding is preferably in the range of 600C to 1200C. A gel temperature lower than 400C results in a greater hardness of the resultant hydrogel, thereby making it difficult to control a particle shape and size distribution in grinding (paragraph 0205). Therefore, it is the Office’s position that it is within the scope of one skilled in art prior to the filing of present invention to set the gel temperature T2 at the discharge port to be higher than gel temperature T1 at the input port as in present claim 5, and inside of the main body to 500C or higher as in present claim 9, absent evidence to the contrary. Case law holds that differences in concentration or temperature will not support patentability of the subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. MPEP 2144.05. As such, Machida et al shows that temperature of the crosslinked hydrogel influences particle shape and particle size distribution and thus would be considered a result effective variable. Thus, it would have been obvious to one of ordinary skill in the art to have optimized the temperature through routine optimization. However, changes such as presently claimed temperature ranges may impart patentability to the process if the particular temperature claimed produces a new and unexpected result which is different in kind and not merely in degree from the results of the prior art, see In re Boesch and Slaney, 2003 USPQ 215 (CCPA 1980).
Regarding claim 8, see example 1, of Machida et al, wherein after the gel grinding, the particulate hydrogel had a temperature of 850C (paragraph 0465).
Regarding claim 10, Machida et al teach that polymerization is carried out continuously to prepare a hydrogel in the shape of a belt (paragraph 0456) which reads on crosslinked hydrogel polymer obtained after the polymerization step has a sheet form in present claim 10. Hydrogel after polymerization can be cut to have a size of several tens of centimeters before the gel grinding (paragraph 0238) which reads on chopping step of chopping the crosslinked hydrogel polymer having the sheet form before the gel-crushing step in present claim 10.
Regarding claim 11, Machida et al teach that in the gel grinding step water can be added to the hydrogel in the form of solid, liquid or gas (paragraph 0242) which reads on water and/or water vapor is supplied to inside of the main body in gel-crushing step as in present claim 11.
Regarding claim 12, Machida et al teach that when water is in the form of liquid, temperature of the water is preferably in the range of 400C to 1000C. In case where the water is a gas, temperature of water is preferably in the range of 1000C to 1300C (paragraph 0245) which overlaps with the temperature of water and/or water vapor in present claim 12.
Regarding claim 13, Machida et al teach that water in the form of gas is preferably water having a pressure higher than atmospheric pressure (paragraph 0245) which overlaps with the pressure of water vapor supplied to inside of the main body in present claim 13.
Regarding claim 14, see production example 1, of Machida et al, wherein belt shaped hydrogel is produced and has a solids content of 53.0 wt% (paragraph 0456) which reads on the solids content of the crosslinked hydrogel polymer to be put into the input port as in present claim 14.
Regarding claim 15, see example 1, of Machida et al, wherein resin solids content of particulate hydrogel after the gel grinding is 50.8 wt% (paragraphs 0465 to 0466).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Machida et al (US 2013/0026412 A1) in view of Hatsuda et a (EP 0 925 836 A1).
The discussion with respect to Machida et al in paragraph 9 above is incorporated here by reference.
Machida et al are silent with respect to disk shaped crusher and minimum clearance.
However, Hatsuda et at teach a method comprising pulverizing a hydrogel polymer. The hydrogel polymer is sheared between two spiral rotary blades with different feed rates provided opposite one another (abstract). The interval D1 at which the rotating blades 6 and 7 cross, the interval D2 at which the rotating blades 6 and 8 cross, and the interval D3 at which the rotating blades 7 and 8 cross are each preferably set preferably in a range of 0.05 mm to 0.5 mm. The intervals D4 and D5 between the inner wall of the crushing chamber 2 and the facing surfaces 6c and 7c of the rotary blades 6 and 7, respectively, and the spacings D6 and D7 between the inner wall of the crushing chamber 2 and the facing surface 8a of the rotary blade 8 are each preferably set in the range of 1 mm to 20 mm. The size of the comminuted hydrogel polymer is determined by the intervals D1, D2 and D3. If the intervals D1, D2 and D3 are too large, the hydrogel polymer cannot be finely pulverized. If on the other hand the intervals D1, D2 and D3 are less than 0.01 mm, the pulverized hydrogel polymer may be too fine (paragraph 0051). It is preferable to set heights S1, S2 and S3 of the rotating blades 6, 7 and 8, respectively, preferably in the range of 5 mm to 50 mm (paragraph 0052). Therefore, in light of the teachings in Hatsuda et al, it would have been obvious to one skilled in art prior to the filing of present application to use a twin screw extruder including rotary blades and optimizing the minimum clearance C of 0.2 to 20% relative to of a maximum disk diameter D for obtaining the desired particle size, absent evidence to the contrary.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARUNA P REDDY whose telephone number is (571)272-6566. The examiner can normally be reached 8:30 AM to 5:00 PM M-F.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Arrie (Lanee) Reuther can be reached at 571-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/KARUNA P REDDY/Primary Examiner, Art Unit 1764
Prosecution Insights