DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1, and 10 have been amended. Claim 6 is cancelled. Claims 1-5, and 7-12 are pending, and are under examination on the merits.
Response to Amendment
The Amendment by Applicants’ representative Lingyan Wang on 12/17/2025 has been entered.
Response to Arguments/Amendments
Claim rejection under 35 U.S.C.§103(a)
Applicant amended claim 1 by further limiting a concentration of the compound of Formula 1
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in the surface crosslinking solution is 1 N to 10 N. In addition, Applicant argued that all the cited art is silent about an interpenetrating polymer network (IPN) on a surface of a base polymer powder. In addition, Applicant argued that claim 1 as amended specifically limits that a concentration of the compound represented by Chemical Formula 1 in the surface crosslinking solution is 1 N to 10 N, while none of the prior art teaches the concentration of the dialdehyde in the claimed range.
Applicant’s arguments have been fully considered, but not sufficient to overcome the rejection.
Regarding Applicant’s argument “all the cited art is silent about an interpenetrating polymer network (IPN) on a surface of a base polymer powder”, it would have been an inherited of the process to form an interpenetrating polymer network on a surface of the base polymer powder based on the process of cited prior art references.
Regarding Applicant’s amendment to include “a concentration of the compound represented by Chemical Formula 1 in the surface crosslinking solution is 1 N to 10 N”, it is further taught and/or suggested by an additional reference US2014/0158355, necessitated by the amendment. Therefore, the rejection is revised, and maintained.
Claim Rejections - 35 USC § 103 (revised)
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-5, and 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over US2007207924A1 (“the `924 publication”) to Ikeuchi et al. in view of US2003125684A1 (“the `684 publication”) to Jian Qin, and Fan et al., Journal of Gaofenzi Cailiao Kexue Yu Gongcheng, (2011), 27(3), 120-123, Dai et al., Chemical Engineering Journal, (2010), v.165, p.240-249, and US2014/0158355A1 (“the `355 publication”) to Wuthrich et al.
Applicant’s claim 1 is drawn to a method of preparing a superabsorbent polymer, the method comprising: 1) carrying out a crosslinking polymerization of a water-soluble ethylene-based unsaturated monomer having acidic groups which are at least partially neutralized, in the presence of an internal crosslinking agent, to form a water-containing gel polymer including a first crosslinked polymer; 2) coarsely pulverizing the water-containing gel polymer; 3) drying, pulverizing, and size-sorting the water-containing gel polymer to form a base polymer powder; and 4) reacting the base polymer powder with a surface crosslinking solution to form an interpenetrating polymer network on a surface of the base polymer powder, wherein the surface crosslinking solution includes a monomer having an amine group and a compound represented by the following Chemical Formula 1
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, wherein n is an integer of 1 to 10, and wherein a concentration of the compound represented by Chemical Formula 1 in the surface crosslinking solution is 1 N to 10 N.
Determination of the scope and content of the prior art (MPEP §2141.01)
The `924 publication (claim 8) discloses a method for production of an aqueous-liquid-absorbing agent including water-absorbent resin particles as essential components comprising the steps of: preparing an aqueous monomer solution including a water-soluble ethylenically unsaturated monomer and an internal-crosslinking agent of not less than 0.2 mol % in ratio to the monomer; and then polymerizing and internal-crosslinking the water-soluble ethylenically unsaturated monomer in the aqueous monomer solution to form a hydrogel; and then extruding the hydrogel from a perforated structure having perforation diameters in the range of 0.3 to 6.4 mm to thereby pulverize the hydrogel to thus obtain pulverized gel particles; drying the pulverized gel particles to thereby obtain the water-absorbent resin particles; and surface-crosslinking the water-absorbent resin particles. Example 1 of the `924 publication [0180-0189] discloses a specific method for preparing a surface crosslinked superabsorbent polymer comprising carrying out a crosslinking polymerization of a water-soluble partially neutralized acrylic acid in the presence of an internal crosslinking agent of polyethylene glycol diacrylate ands polymerizing initiator of sodium persulfate. The resultant polyacrylate hydropolymer (hydrogel) was pulverized coarsely and dried at 180 °C for 40 minutes to form a base polymer powder. The resultant base polymer powder was reacted with a surface crosslinking aqueous solution comprising a mixed liquid of 0.3 weight part of 1,4-butanediol, 0.6 weight part of propylene glycol, 3.0 weight parts of pure water, and 1.0 weight part of isopropyl alcohol to form an interpenetrating polymer network on a surface of the base polymer powder.
The `684 publication [0014] discloses water swellable, insoluble polymers are crosslinked using a permanent crosslinking agent including diamines and polyamines. The `684 publication [0050] discloses the polymer can be crosslinked using a permanent crosslinking agent to an extent which enables the polymer to have a high free swell capacity but a low absorbency under load (AUL) value, and examples of such suitable crosslinking agents include glutaraldehyde, diamines, and polyamines.
Fan et al. discloses a method of preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker.
Dai et al. discloses a high concentrated HCl aqueous solution was added in the preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads. For guarantee the stability in acidic medium, CS/PAA beads have been also chemically cross-linked by GLA further. (see “3.1. Preparation of CS-GLA and CS/PAA-GLA beads” at p.242) to make the reaction under acidic condition.
Ascertainment of the difference between the prior art and the claims (MPEP §2141.02)
The difference between Applicant’s claim 1 and the `924 publication is that the prior art does not teach the surface crosslinking solution includes a monomer having an amine group and a compound represented by the following Chemical Formula 1
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, wherein n is an integer of 1 to 10. Instead, the `924 publication teaches the surface crosslinking solution includes 1,4-butanediol, 0.6 weight part of propylene glycol, 3.0 weight parts of pure water, and 1.0 weight part of isopropyl alcohol. In addition, the `924 publication does not teach a concentration of the compound represented by Chemical Formula 1 in the surface crosslinking solution is 1 N to 10 N.
Finding of prima facie obviousness--rational and motivation (MPEP §2142-2413)
However, the difference is taught and/or suggested by the `684 publication and Fan et al., because the `684 publication [0050] discloses the polymer can be crosslinked using a permanent crosslinking agent to an extent which enables the polymer to have a high free swell capacity but a low absorbency under load (AUL) value, and examples of such suitable crosslinking agents include glutaraldehyde, diamines, and polyamines, and Fan et al. discloses preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker, wherein glutaraldehyde reads on the Chemical Formula 1
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, wherein n=3, and chitosan contains amine groups.
In terms of the concentration of the compound represented by Chemical Formula 1 in the surface crosslinking solution is 1 N to 10 N (amended), the `355 publication [0085] teaches a method of glutaraldehyde crosslink using a 20 wt% solution of glutaraldehyde in water. Based on calculation, molarity of a 20 wt% glutaraldehyde aqueous solution is approximately 2.10 M, or 2.10 N, based on the following calculation:
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Therefore, the `924 publication in view of the `684 publication, Fan et al. and the `355 publication would have rendered claim 1 obvious.
In terms of claim 2, wherein a solvent of the surface crosslinking solution is water, Example 1 of the `924 publication [0180-0189] discloses the surface crosslinking solution comprising pure water as a solvent.
In terms of claim 3, wherein a pH of the surface crosslinking solution is 1 to 3,
Dai et al. discloses a high concentrated HCl aqueous solution was added in the preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads. For guarantee the stability in acidic medium, CS/PAA beads have been also chemically cross-linked by GLA further. (see “3.1. Preparation of CS-GLA and CS/PAA-GLA beads” at p.242) to make the reaction under acidic condition. Therefore, for one ordinary skilled in the art, applying a pH of the surface crosslinking solution of 1 to 3 would have been an obvious-to-try in view of the Dai’s disclosure.
In terms of claim 4, wherein the monomer having an amine group is chitosan or cyclodextrin, Fan et al. discloses preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker; and Dai et al. teaches preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads.
In terms of claims 5, 7, and 10, Fan et al. discloses preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker; and Dai et al. discloses a high concentrated HCl aqueous solution was added in the preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads. For guarantee the stability in acidic medium, CS/PAA beads have been also chemically cross-linked by GLA further. (see “3.1. Preparation of CS-GLA and CS/PAA-GLA beads”, AND Scheme 1 at p.242 and the cited references [13,18]) to make the reaction under acidic condition. Using various concentration of the monomer having an amine group or the aldehyde for the surface crosslinking reaction would have been routine experimentation based on the disclosures of Fan et al. and Dai et al. The selection of reaction conditions is more optimization by more modification of routine experimentation and within one skilled in the art. Changes in temperature, concentration, or both are not patentable modification in the absence of unexpected results which is different in kind and not degree. In re Aller, 220 F.2d 454, 105 USPQ 233 (CCPA 1955).
In terms of claim 8, wherein n of Chemical Formula 1 is an integer of 2 to 4, Fan et al. discloses preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker; and Dai et al. teaches preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads, wherein n=3.
In terms of claim 9, wherein the compound represented by Chemical Formula 1 is glutaraldehyde, Fan et al. discloses a method of preparing sodium polyacrylate-chitosan interpenetrating polymer sponge by reacting sodium polyacrylate and chitosan as raw materials, and glutaraldehyde as a crosslinker; and Dai et al. teaches preparation process for CS/PAA-GLA [glutaraldehyde cross-linked poly(acrylic acid)blended chitosan] beads.
In terms of claims 11 and 12, they are inherited properties of the prepared products, which are naturally flown from the product prepared by the otherwise obvious method of preparing the product disclosed by the `924 publication, the `684 publication, Fan et al., and Dai et al.
Conclusions
Claims 1-5, and 7-12 are rejected.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 extension fee 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 date of this final action.
Telephone Inquiry
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Yong L. Chu, whose telephone number is (571)272-5759. The examiner can normally be reached on M-F 8:30am-5:00pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Amber R. Orlando can be reached on 571-270-3149. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
/YONG L CHU/Primary Examiner, Art Unit 1731