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 .
Response to Amendment
This action is responsive to applicant’s amendment filed 11/4/2025.
Claims 1-20 are pending.
The previous rejection of claim 3, and 10-19 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, is maintained in view of applicant’s amendment.
The previous rejection of claims 1-20 under 35 U.S.C. 103 as being unpatentable over Robinson et al (US4,983,698) in view of Kayser et al (US2019/0241509) is maintained in view of applicant’s amendment.
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.
Claim 3, and 10-19 are 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.
Claims 3 and 10 recite the limitation "2-methylidene-1,3- propylenedisulfonic acid" in line 2. There is insufficient antecedent basis for this limitation in the claim.
Claims 11-19 are rejected as being dependent on rejected claims.
Claim Rejections - 35 USC § 103
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Robinson et al (US4,983,698) in view of Kayser et al (US2019/0241509).
Regarding claims 1-4, 7, 10, 11, Robinson discloses a polymer composition comprising a water-soluble cationic copolymer obtained by radical polymerization of at least one non-ionic monomer acrylamide, at least one dialkylaminoalkyl acrylate cationic monomers (col 1, ln 7-14), in present of a homopolymer (at least 1% by weight of 2-acrylamido-2-methylpropane sulfonic acid and salt thereof, col 6, ln 52-65). Robinson does not disclose the 2-acrylamido-2-methylpropane sulfonic acid having an average molecular weight between 5,000 and 100,000 Daltons, and has been prepared from 2-acrylamido-2- methylpropane sulphonate in salified form in the presence of 200 to 20,000 ppm by weight of 2-methyl-2-propenyl-sulphonic acid in salified form as recited in the claim.
Kayser teaches a polymer of 2-acrylamido-2-methylpropane sulfonic acid and salt thereof (formula 3, acryloyldimethyltaurate, ACDMT or 2- acrylamido-2-methylpropane sulfonic acid salt) prepared in the presence of 0.02-0.06 wt% (200-600pm) of 2-methyl-2-propenyl sulfonic acid (Isobutene sulfonic acid IBSA and/or 0.015-0.124 wt% (150-1240ppm) of 2-methylidene-1,3-propylenedisulfonic acid IBDSA (Tables 4 and 6). Since the reaction mixture was naturalized with sodium hydroxide, the IBSA and IBDSA should be present in salified forms of sodium salts. The polymer has a weight average molecular weight of at least 700 g/mol, preferably from 700 g/mol to 10 million g/mol (para 0063). The 2- acrylamido-2-methylpropane sulfonic acid salt of Kayser is a bio-based polymer, more sustainable and biodegradable, which is environmentally friendly. It would have been obvious to one of ordinary skill in the art before the filling date of the invention to use the 2- acrylamido-2-methylpropane sulfonic acid salt of Kayser in polymerization of the water-soluble polymer of Robinson with reasonable expectation of success. Case law holds that the mere substitution of an equivalent (something equal in value or meaning) is not an act of invention; where equivalency is known to the prior art, the substitution of one equivalent for another is not patentable. See In re Ruff 118 USPQ 343 (CCPA 1958).
Robinson does not disclose the water-soluble cationic copolymer is structured in micro-blocks. However, the water-soluble cationic copolymer is obtained under the same conditions as presently claimed, and the copolymer would be expected to have the claimed structure.
Regarding claim 5, Robinson discloses bi-phase initiator system promotes smooth conversion profiles, generating linear high molecular weight polymer in high yields (page 5, ln 20-22) and the use of careful pH control to minimize undesirable side reactions, i.e. degradation of polymer molecular weight (page 5, ln 40-45). This would indicate to one of ordinary skill in the art that alterations of the process conditions such as selecting and altering the amount of initiator and/or pH would also be able to alter the molecular weight of the polymer.
Regarding claims 6, 14 and 16, Robinson discloses the least one dialkylaminoalkyl acrylate cationic monomers include the quaternaries of dimethylaminoethyl acrylate (DMAEA) and dimethylaminoethyl methacrylate (DMAEMA) (page 4, ln 22-28).
Regarding claim 8, Robinson discloses the cationic monomer represents 10 to 85 wt% and the nonionic monomer represents 5 to 80 wt% (page 7, ln 8-12).
Regarding claim 9, Robinson does not disclose the ratio of the moles of cationic monomers relative to the moles of 2- acrylamido-2-methylpropane sulfonate in salified form in P1 is between 0.2 and 3. However, Robinson discloses the 2- acrylamido-2-methylpropane sulfonate, when copolymerized with the cationic monomer and the acrylamide will yield water-soluble polymers. The term "water-soluble" means that the polymer is soluble in water in an amount of at least 1% by weight (page 6, ln 53-58). ). It would have been obvious to one of ordinary skill in the art before the filling date of the invention to determine to mole ratio of cationic monomers relative to the moles of 2- acrylamido-2-methylpropane sulfonate in salified form in P1 to arrive at the claimed ratio and to yield the polymer that is soluble in water in an amount of at least 1% by weight, absent any showing of unexpected results or criticality.
Regarding claim 12, 13, 15, 17, Robinson discloses bi-phase initiator system promotes smooth conversion profiles, generating linear high molecular weight polymer in high yields (page 5, ln 20-22) and the use of careful pH control to minimize undesirable side reactions, i.e. degradation of polymer molecular weight (page 5, ln 40-45). This would indicate to one of ordinary skill in the art that alterations of the process conditions such as selecting and altering the amount of initiator and/or pH would also be able to alter the molecular weight of the polymer.
Regarding claim 18, Robinson discloses the cationic monomer represents 10 to 85 wt% and the nonionic monomer represents 5 to 80 wt% (page 7, ln 8-12).
Regarding claim 19, Robinson does not disclose the ratio of the moles of cationic monomers relative to the moles of 2- acrylamido-2-methylpropane sulfonate in salified form in P1 is between 0.2 and 3. However, Robinson discloses the 2- acrylamido-2-methylpropane sulfonate, when copolymerized with the cationic monomer and the acrylamide will yield water-soluble polymers. The term "water-soluble" means that the polymer is soluble in water in an amount of at least 1% by weight (page 6, ln 53-58). It would have been obvious to one of ordinary skill in the art before the filling date of the invention to determine to mole ratio of cationic monomers relative to the moles of 2- acrylamido-2-methylpropane sulfonate in salified form in P1 to arrive at the claimed ratio and to yield the polymer that is soluble in water in an amount of at least 1% by weight, absent any showing of unexpected results or criticality.
Regarding claim 20, Robinson discloses a method of treating waste water by using the water-soluble cationic copolymer as a flocculant (col 3, ln 10-13 and example III).
Response to Arguments
Applicant's arguments filed 11/4/2025 have been fully considered but they are not persuasive.
Regarding the rejection of claim 3, and 10-19 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, applicant argued that 2-methylidene-1,3- propylenedisulfonic acid is introduced in claims 3 and 10, which provide proper antecedent basis support for the limitation. Examiner respectfully disagrees. Claims 3 and 10 further limits 1 and 2, respectively. Claims 1 and 2 both recite “wherein the homopolymer P1 is prepared in the presence of 300 to 10,000 ppm by weight of 2-methyl-2-propenyl-sulphonic acid in salified form." “2-methylidene-1,3- propylenedisulfonic acid” and “2-methyl-2-propenyl-sulphonic acid” are two different compounds, and thus “2-methyl-2-propenyl-sulphonic acid” does not provide proper antecedent basis support for “2-methylidene-1,3- propylenedisulfonic acid”.
Regarding the rejection of claims 1-20 under 35 U.S.C. 103 as being unpatentable over Robinson et al (US4,983,698) in view of Kayser et al (US2019/0241509), applicant argued that a prima facie case of obviousness does not exist for the claimed invention of claim 1 and even if a prima facie case of obviousness had been established, it would be rebutted by relevant secondary considerations. Specifically, applicant argued that a person having ordinary skill in the art would lack a motivation to modify Robinson in view of Kayser to arrive at the claimed invention. Indeed, there is a structural distinction in that Robinson only teaches a single copolymer; it never polymerizes in the presence of an ATBS (2-acrylamido-2- methylpropane sulphonate) homopolymer, and there is no motivation for a skilled person to do so. Examiner respectfully disagrees. Robinson clearly discloses the water-soluble cationic copolymer is prepared in the presence of at least 1% by weight of monomer 2-acrylamido-2-methylpropane sulfonic acid and salt thereof, col 6, ln 52-65). The examiner also notes that one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Keyser discloses a is a bio-based polymer, sustainable, biodegradable, and environmentally friendly 2- acrylamido-2-methylpropane sulfonic acid salt. One of ordinary skill in the art before the filling date of the invention would use the 2- acrylamido-2-methylpropane sulfonic acid salt of Kayser in polymerization of the water-soluble polymer of Robinson with reasonable expectation of success because it is held that the mere substitution of an equivalent (something equal in value or meaning) is not an act of invention; where equivalency is known to the prior art, the substitution of one equivalent for another is not patentable. See In re Ruff 118 USPQ 343 (CCPA 1958). The polymer of Keyser has a weight average molecular weight of at least 700 g/mol, preferably from 700 g/mol to 10 million g/mol (para 0063), which overlapping the claimed weight average molecular weight. Product claims with numerical ranges which overlap prior art ranges were held to have been obvious under 35 USC 103, See In re Wertheim 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) and MPEP 2144.05, I.
Applicant also argued that the present invention shows unexpected functional performance, including improved retention, drainage, and flocculation due to the fined molecular weight (MW) range of the P1 (2- acrylamido-2-methylpropane sulfonic acid) and therefore would sufficient to overcome a prima facie case of obviousness. Examiner respectfully disagrees. The law held that whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). The claimed MW range of P1 is between 5000 and 100,000 Daltons. The examples only show two values (47,000 and 24,600), which is insufficient to show the results occur over the entire claimed range. In addition, to establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). One comparative example does not show the criticality of the entire claimed range. The evidence insufficient to rebut the prima facie case of obviousness.
Claims 1-20 remain unpatentable the reasons of record.
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.
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/HAIDUNG D NGUYEN/Primary Examiner, Art Unit 1761
2/18/2026