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
Acknowledgment is made of applicant’s claim for foreign priority (JP2019-191204, filed on 18 October 2019) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Interpretation
Claim 1 recites “treating water-absorbing resin particles that have absorbed water with hot water of 65°C or higher,” “treating the water-absorbing resin particles after the hot water treatment with a hydrophilic organic solvent,” and “wherein 70 to 100 mol% of crosslinked polymer present in the water-absorbent resin particles is represented by at least one selected from the group consisting of poly(meth)acrylic acid and poly(meth)acrylic acid salt.”
Under the broadest reasonable interpretation, Claim 1 is directed to a method of treating existing water-absorbing resin particles that have absorbed water as part of a regeneration process. In plain terms, the claim is directed to using treatment steps on existing used water-absorbing resin particles, not to originally making the water-absorbing resin particles from monomers and not to the water-absorbing resin particles as a product by themselves. The recited poly(meth)acrylic acid / poly(meth)acrylic acid salt limitation is considered as identifying the material acted upon by the claimed treatment steps. MPEP § 2116 requires consideration of all limitations in a method claim while recognizing that obviousness is a fact-specific inquiry based on the claimed subject matter as a whole. Thus, the pertinent prior-art inquiry is whether the prior art teaches or renders obvious treating known water-absorbing resin particles having the recited poly(meth)acrylic acid / salt composition with hot water followed by hydrophilic organic solvent as part of a regeneration method.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over IMURA et al. (JP2003326161A, hereinafter IMURA).
Regarding Claims 1–5 and 7, IMURA discloses a method for regenerating water-absorbent resins suitable for use in sanitary materials such as paper diapers, sanitary napkins, and incontinence pads (¶[0001]).
The resin is a water-swellable crosslinked polymer, including partially neutralized crosslinked polyacrylic acid polymers. Preferred materials are polyacrylic acid salt based crosslinked polymers containing acrylic acid or its salt as the main component, and 50–90 mol% of the acid groups in the polymer are neutralized to form salts (¶¶[0012]–[0013]). The water absorbent resin is a crosslinked product of partially neutralized sodium polyacrylate, which is widely used in paper diapers and the like (¶[0035]).
The used swollen absorbent core includes water absorbent resin and hydrophilic fibers such as cotton-like pulp, and the water absorbent resin and the cotton-like pulp are separated from the used swollen absorbent core to recover used water absorbent resin for regeneration (i.e., Claim 5, Claim 7; ¶[0029]). The washing treatment removes absorbed liquid from the swollen gel of the water absorbent resin. Washing includes contacting the swollen gel with water or salt water, a hydrophilic organic solvent, or water mixed with a hydrophilic organic solvent (¶[0031]). The dehydration step may be carried out after the washing step (¶[0039]).
Regarding the claimed “poly(meth)acrylic acid and poly(meth)acrylic acid salt,” it is reasonable to interpret the claimed material as encompassing the genus of polyacrylic acid, polymethacrylic acid, and salts thereof. The disclosed polyacrylic acid salt based crosslinked polymer is within the claimed genus. Selecting this known water-absorbent resin material for the disclosed regeneration process would have predictably treated used water-absorbent resin particles as intended.
Hydrophilic organic solvent examples include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and acetone (i.e., Claim 3, Claim 4; ¶[0032]). Dehydration reduces the water content of the swollen water absorbent resin, and includes dehydrating a swollen water absorbent resin gel by adding it to a water-soluble hydrophilic organic solvent (¶[0033]).
For a temperature sensitive N-alkyl (meth)acrylamide or N,N-dialkyl (meth)acrylamide absorbent resin, the resin that has absorbed urine is placed under temperature conditions that discharge liquid, where the discharge temperature is 80°C or higher, and the treatment is carried out with the resin dispersed in water for cleaning and to prevent discoloration (¶[0038]). The discharge temperature of 80°C or higher falls within the claimed “hot water of 65°C or higher.”
In view of IMURA’s disclosure that regeneration includes washing and dehydration operations, where washing removes absorbed liquid from swollen water-absorbent resin and hydrophilic organic solvent dehydration reduces water content, it would have been obvious to select hot aqueous treatment followed by hydrophilic organic solvent treatment as an ordered regeneration sequence because the hot aqueous treatment would clean the used resin particles and the subsequent hydrophilic organic solvent treatment would predictably reduce water content.
The water absorbing agent may be subjected to a drying treatment in order to further reduce the water content (¶[0040]). In Example 2, the water absorbing agent is vacuum dried at 60°C to carry out a dehydration treatment, and the water absorbing agent has a moisture content of 5% (i.e., Claim 2; ¶[0056]), which is less than the claimed total content of water and hydrophilic organic solvent of less than 15% by mass.
In Example 1, a reaction liquid is prepared by dissolving 8.1 parts polyethylene glycol diacrylate in 5,500 parts of a 38 wt% aqueous solution of sodium acrylate at a neutralization rate of 71 mol%, then polymerizing to obtain a hydrous gel polymer (¶[0050]). Based on the disclosed data from Example 1, the sodium acrylate content of the monomer component used to form the crosslinked polymer is calculated as 99.818 to 99.964 mol%. This calculated value supports that the resulting crosslinked polymer is represented by polyacrylic acid salt in an amount within the claimed 70 to 100 mol% range. See calculation provided in the previous Office action.
Regarding Claims 6 and 8, IMURA makes obvious the method for reproducing water-absorbing resin particles of Claim 1. Neutral water is pH 7, and it is reasonable to interpret that the water used in IMURA is near neutral, about pH 6 to 8, which falls within the claimed “pH range of 5 to 9.”
Response to Arguments
Applicant’s arguments, see Remarks, filed on March 3, 2026, have been fully considered but are not persuasive. The rejection of Claims 1–8 under 35 U.S.C. § 103 over IMURA is maintained and updated.
Applicant’s argument focuses on whether one IMURA embodiment/example expressly contains every feature. But the rejection is under §103. The rejection relies on IMURA’s disclosed regeneration process as a whole, including the known polyacrylic acid salt resin material, washing/dehydration operations, hot aqueous treatment, and hydrophilic organic solvent dehydration.
Applicant’s argument regarding Example 1 and Example 5 is not persuasive because the rejection does not rely on Example 5 as the sole basis for the claimed resin composition. Example 1 supports the claimed polyacrylic acid salt material/content, while IMURA’s broader regeneration disclosure supports the washing/dehydration treatment sequence, including hot aqueous treatment and hydrophilic organic solvent treatment. A single working example is not required to establish obviousness under 35 U.S.C. § 103.
Applicant argues that Example 5 contains about 74.2 mol% N-isopropylacrylamide and therefore does not satisfy the claimed 70 to 100 mol% poly(meth)acrylic acid / salt limitation. This argument is not persuasive because the rejection does not rely on Example 5 for the claimed resin composition. Rather, the claimed material limitation is supported by IMURA’s disclosure of polyacrylic acid salt based crosslinked polymers and the calculated polyacrylic acid salt content from Example 1.
Applicant’s argument is not commensurate with the scope of Claim 1. Claim 1 broadly requires hot-water treatment followed by hydrophilic organic solvent treatment, but does not require the specific resin mechanism or working-example separation relied upon by Applicant. Hydrophilic organic solvent treatment is expressly disclosed as a dehydration operation in IMURA, and using it after aqueous treatment would have predictably reduced water content from the treated resin particles.
Applicant’s reliance on IMURA’s acidic compound shrinkage disclosure is not persuasive. IMURA’s disclosure of acidic compound shrinkage for partially neutralized sodium polyacrylate identifies one disclosed regeneration route, but does not exclude the use of hot aqueous treatment followed by hydrophilic organic solvent treatment. Applicant has not shown that the claimed sequence provides an unexpected result or critical effect over the disclosed regeneration operations.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAK L. CHIU whose telephone number is (703)756-1059. The examiner can normally be reached M-F: 9:00am - 6:00pm (CST).
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, PREM C. SINGH can be reached at (571)272-6381. 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.
/TAK L. CHIU/Examiner, Art Unit 1777
/KRISHNAN S MENON/Primary Examiner, Art Unit 1777
Prosecution Insights