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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 February 17, 2026 has been entered.
Response to Amendment
The Amendment filed February 17, 2026 has been entered. Examiner acknowledges the addition of new claims 14-32. Claims 6 and 14-32 remain pending in the application.
Response to Arguments
Applicant's arguments filed February 17, 2026 have been fully considered but they are not persuasive. Claims 12 and 13 have been cancelled; therefore, the prior rejections of those claims are moot. The rejection of claim 6 over Yamaguchi is maintained.
Applicant argues that Yamaguchi provides no motivation to increase decarboxylation and instead treats decarboxylation as an undesirable side reaction. This argument is not persuasive. Yamaguchi expressly teaches that carbon dioxide evolves during polymerization as a result of decarbonization of maleic acid and/or the acid-type maleic acid polymer, that the amount of carbon dioxide evolved is proportional to the amount of hydrogen peroxide added, and that the amount of decarbonization and resulting carboxyl groups in the polymer may thereby be controlled as required. Yamaguchi further explains that controlling the carboxyl-group content permits the polymer to be made suitable for a broad range of applications because carboxylic acid content affects polymer properties and performance. Thus, Yamaguchi does not teach avoidance of decarboxylation; it teaches controlled selection of decarboxylation as a result-effective variable affecting the intended water-treatment polymer. Selecting a degree of decarboxylation sufficient to meet the claimed minimum of 5 molar% would have been an obvious optimization of Yamaguchi’s disclosed process.
Applicant also argues that the Third Farrar Declaration shows no reasonable expectation of success. The Declaration has been carefully considered, but it is not persuasive. First, the experiments identified as reproductions of Yamaguchi Examples 8 and 9 do not appear to reproduce those examples as actually taught. The Declaration states that, for testing both Yamaguchi Example 8 and Example 9, “ferrous ammonium sulphate (FAS)” was added to the reaction vessel. However, Yamaguchi Examples 8 and 9 were Fe3+ examples, not Fe2+ examples. Ferrous ammonium sulfate contains Fe2+. Thus, the Declaration’s reported results are not shown to be representative of Yamaguchi’s actual Examples 8 and 9 and do not establish that Yamaguchi’s disclosed Fe3+ process would fail to achieve, or render obvious, the claimed decarboxylation level. Second, even accepting the Declaration’s modified testing at Face value, the data do not establish a meaningful technical boundary at 5 molar%. In the third round of testing, the Declaration reports decarboxylation values of 4.94% and 4.74%. These values are immediately adjacent to the claimed “at least 5 molar%” threshold. Applicant has not provided evidence that a polymer having 5.00 molar% decarboxylated maleic acid repeating units produces any unexpected result or patentable distinction relative to polymers having 4.94% or 4.74% decarboxylation. Accordingly, the Declaration does not rebut the conclusion that the claimed value would have been an obvious optimization of Yamaguchi’s controllable decarbonization process.
Applicant also argues that certain modified experiments produced discoloration and therefore would render Yamaguchi unsuitable for its intended purpose. This argument is not persuasive because the discoloration evidence is not commensurate with the full scope of Yamaguchi’s disclosure or the pending claims. As noted above, the experiments used ferrous ammonium sulphate rather than reproducing Yamaguchi’s Fe3+ Examples 8 and 9. The Declaration therefore does not establish that Yamaguchi’s actual examples, or Yamaguchi’s broader disclosed metal-ion systems, would necessarily produce unacceptable discoloration when adjusted to obtain the claimed decarboxylation level. Moreover, the claims do not recite color, absence of discoloration, or any limitation requiring a particular commercial appearance of the polymer.
Further, even under the altered experimental conditions selected by the Declarant, the reported third-round testing produced samples having 4.94% and 4.74% decarboxylation. Although those reported values are numerically below the claimed minimum of 5 molar%, they are very near the claimed boundary and do not establish that the claimed threshold is critical, unexpected, or unobtainable through routine adjustment of the process variables that Yamaguchi expressly identifies as controlling decarboxylation. Rather, these results are consistent with Yamaguchi’s teaching that the degree of decarboxylation is a controllable polymer-property variable.
Accordingly, Applicant’s arguments and the Third Farrar Declaration do not overcome the prima facie case of obviousness. Yamaguchi expressly teaches controlling decarboxylation in its acid-type maleic acid polymer through disclosed polymerization variables in order to control polymer properties and performance, and the claimed minimum degree of decarboxylation would have been an obvious result of routine optimization of that disclosed process. The rejection of claim 6 under 35 U.S.C. §103 over Yamaguchi is therefore maintained.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 20, 25 and 27 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 20 recites “wherein said copolymer comprises a polymer backbone having a plurality of di-carboxylic acid repeating units positioned along the backbone such that electrostatic repulsion between adjacent carboxylate groups provides stability of the copolymer in aqueous systems having a calcium ion concentration of about 600 mg/L to about 1200 mg/L and a pH of about 9.0 to about 10.2.” Although the specification generally discusses electrostatic repulsion and polymer stability in harsh water conditions, it does not disclose this asserted functional relationship throughout the claimed combined calcium concentration and pH range. The claimed range is assembled from separate testing conditions, without express disclosure that electrostatic repulsion provides copolymer stability across that combined range.
Claim 25 recites that the copolymer provides crystal habit modification as a “dominant scale-control mechanism relative to threshold inhibition” under conditions producing bulk precipitation. The specification discusses prioritizing crystal habit modification as a primary functionality and describes its importance under bulk-precipitation conditions, but it does not disclose that crystal habit modification is dominant relative to threshold inhibition for the claimed copolymer.
Claim 27 recites that the copolymer has a higher proportion of non-carboxylated repeating units than polymaleic acid homopolymers. The specification states that comparison of FIG. 15, identified as prior art copied from Yamaguchi, with FIG. 16 shows a higher proportion of decarboxylated repeating units in the enhanced copolymer. However, the specification does not identify the FIG. 15 material as a polymaleic acid homopolymer or otherwise disclose comparison against polymaleic acid homopolymers as claimed.
Claims 25 and 32 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.
Regarding claim 25, the limitation requiring crystal habit modification to be a “dominant scale-control mechanism relative to threshold inhibition” renders the scope of the claim unclear. The term “dominant” is a relative term of degree. Neither the claim nor the specification provides an objective standard for determining when crystal habit modification is “dominant” relative to threshold inhibition. Although the specification discusses prioritizing crystal habit modification as a primary functionality, it also explains that scale-control mechanisms may operate sequentially or simultaneously. One of ordinary skill in the art would not be able to determine with reasonable certainty when the claimed comparative dominance limitation is satisfied, therefore claim 25 is indefinite.
Regarding claim 32, the claim recites that the copolymer produces “rounded or spherical crystal morphologies that are not produced by polymaleic acid under the same precipitation conditions.” However, the claim does not define the precipitation conditions, polymaleic acid comparator, polymer dosage, calcium/carbonate concentration, pH, temperature, test duration, or objective standard for determining whether a morphology is “rounded or spherical”. The specification demonstrates that crystal morphology is evaluated under selected testing conditions, and publicly available technical literature further indicates that polymaleic-acid-type polymers may produce spherical calcium-carbonate morphology under certain conditions. Accordingly, whether the claimed negative comparative limitation is met depends upon unspecified test parameters, and one of ordinary skill in the art would not be able to determine the metes and bounds of claim 32 with reasonable certainty.
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.
Claims 6, 14, 16, 17 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (US 5135677).
Regarding claim 6, Yamaguchi discloses copolymer comprising: maleic acid monomer units (Yamaguchi abstract “acid-type polymaleic acid and acid-type maleic acid copolymer” are built by polymerizing maleic acid so maleic acid monomer units are integral to the polymer backbone), mono-carboxylic acids (Yamaguchi col. 5 lines 64-67), terminal hydroxyl groups (Yamaguchi col. 5 lines 19-21 isoprenol, prenol, isoprene alcohol and by example of formula 1 each possessing terminal hydroxyl groups), non-ionic functional groups (Yamaguchi col. 5 line 53 “hydroxyl group”) which aid in adsorption onto a crystal surface, wherein said non-ionic functional groups and said terminal hydroxyl groups are formed during an aqueous polymerization process (Yamaguchi col. 9 lines 12-14), so that said copolymer comprises at least approximately 50 molar% maleic acid and up to 50 molar% of free radical polymerized comonomers (Yamaguchi col. 4 lines 11-14).
Yamaguchi does not disclose including at least 5 molar% decarboxylated maleic acid repeating units.
However, Yamaguchi does disclose that the molar% of the non-carboxylated monomeric repeating units in said polymer molecules may be increased proportionally with the amount of hydrogen peroxide added in the reaction adding that “hydrogen peroxide should be used in an amount of 8-100 g, preferably 10-80 g, and more preferably 15-50 g; per mol of the monomer component. (Col 7. Lines 38-57) It would have been obvious to one of ordinary skill in the art at the time of filing to adjust the mass of hydrogen peroxide added to increase the molar% to at least 5 as a matter of optimization and according to Yamaguchi, “This is a great advantage of the ·present invention because the acid-type maleic acid polymer can be made suitable for a broad range of applications by controlling the amount of carboxylic acid which greatly affects the physical properties and performance of the acid-type maleic acid polymer.”
Regarding claim 14, Yamaguchi discloses the copolymer of claim 6, wherein said copolymer comprises both di-carboxylic acid repeating units and mono-carboxylic acid repeating units along a polymer backbone (Yamaguchi col. 16 describes the copolymer having acrylic acid structural units in the molecule and further teaches in col. 7 that the polymerization evolves carbon dioxide as a result of decarbonization from the maleic acid and/or acid-type maleic acid polymer present in the polymerization system. The maleic-acid-derived repeating units provide di-carboxylic acid repeating units, while the acrylic acid structural units resulting from decarbonization provide mono-carboxylic acid repeating units along the polymer backbone).
Regarding claim 16, Yamaguchi discloses the copolymer of claim 6, wherein said copolymer comprises maleic acid repeating units present at greater than 50 molar percent relative to total repeating units (Yamaguchi col. 4 discloses “50-99.9 wt. % of maleic acid (A) and 50-0.1 wt. % of other water-soluble unsaturated monomer (B)”).
Regarding claim 17, Yamaguchi discloses the copolymer of claim 6, wherein said copolymer further comprises acrylic acid repeating units present at up to 50 molar percent (Yamaguchi col. 4 discloses “50-99.9 wt. % of maleic acid (A) and 50-0.1 wt. % of other water-soluble unsaturated monomer (B)” and further in col. 5 teaches acrylic acid repeating units as the other water-soluble unsaturated monomer (B)).
Regarding claim 19, Yamaguchi discloses the copolymer of claim 6, wherein said copolymer has a molecular weight between approximately 300 and 3,000 Daltons (Yamaguchi col. 8 teaches “an acid-type maleic acid polymer which has a number-average molecular weight of 300-5000, preferably 400-3000, and a D-value smaller than 2.5, preferably smaller than 2.0”).
Claims 15 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (US 5135677) as applied to claim 6 above, and further in view of Atkinson (US4900466A) and Green (US4473485).
Regarding claim 15, Yamaguchi discloses the copolymer of claim 6.
Yamaguchi does not expressly disclose that the non-ionic functional groups comprise non-carboxylated hydrocarbon repeating units incorporated into a polymer backbone.
Atkinson is directed to polymeric polycarboxylates used as crystal-growth modifiers in aqueous detergent slurries containing inorganic salts. Atkinson teaches that suitable polymeric polycarboxylate crystal-growth modifiers include “ethylene/maleic acid copolymers, for examples, the EMA (Trade Mark) series ex Monsanto” (Atkinson col. 5). Atkinson further teaches that the polymeric polycarboxylate is incorporated into the aqueous slurry prior to crystallization so as to influence crystal growth and produce modified crystal morphology, teaching use of a maleic-acid-containing crystal-growth-modifying copolymer having ethylene-derived, non-carboxylated hydrocarbon repeating units incorporated into the polymer backbone.
Greene further clarifies the composition of the Monsanto EMA polymer family identified by Atkinson. Greene teaches that “(a) preferred structuring agent of the present invention is the 1:1 copolymer of ethylene with maleic anhydride” and identifies Monsanto EMA-21 as a particularly preferred ethylene maleic anhydride copolymer, with EMA-22 and EMA-24 identified as the acid and sodium-salt forms, respectively, of EMA-21, confirming that Monsanto EMA polymers references by Atkinson contain ethylene-derived repeating units in a maleic-acid/maleic anhydride polymer backbone.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide Yamaguchi’s acid-type maleic acid water-treatment copolymer with non-carboxylated hydrocarbon repeating units as taught by Atkinson and confirmed by Greene. Yamaguchi teaches that maleic-acid copolymer composition and carboxylic-acid content affect the physical properties and performance of the polymer, and expressly contemplates maleic acid copolymers containing additional comonomer-derived functionality for water-treatment applications. Atkinson teaches, in the closely related field of controlling inorganic crystal growth in aqueous systems, that ethylene/maleic acid copolymers of the Monsanto EMA series are suitable polymeric polycarboxylate crystal-growth modifiers. Greene confirms that those known EMA polymers contain ethylene-derived non-carboxylated hydrocarbon repeating units within a maleic-acid/maleic-anhydride copolymer backbone. One of ordinary skill in the art would have been motivated to incorporate known ethylene-derived non-carboxylated hydrocarbon functionality into Yamaguchi’s maleic-acid-based water-treatment polymer to obtain the known crystal-growth modifying functionality associated with such maleic polycarboxylate copolymers and based on the teachings of these references would have a reasonable expectation that the resulting copolymer would retain utility in aqueous inorganic-scale control.
Regarding claim 18, Yamaguchi in view of Atkinson and Greene discloses or makes obvious the copolymer of claim 6, wherein said copolymer further comprises non-ionic two-carbon alkane repeating units present at up to 50 molar percent (Atkinson col. 5 teaches that suitable polymeric polycarboxylate crystal-growth modifiers include ethylene/maleic acid copolymers such as EMA and Greene confirms that the EMA polymer is a 1:1 copolymer of ethylene with maleic anhydride).
Claims 21-22, 24 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (US 5135677) as applied to claim 6 above, and in view of Atkinson (US4900466A) and Greene (US4473485) and further in view of Amik (US4711725).
Regarding claim 21, Yamaguchi discloses the copolymer of claim 6.
Yamaguchi does not expressly disclose that the nonionic functional groups are present as non-carboxylated hydrocarbon repeating units along the polymer backbone and increase adsorption of the copolymer onto a forming mineral crystal surface during crystal growth.
Atkinson is directed to polymeric polycarboxylates used as crystal-growth modifiers in aqueous detergent slurries containing inorganic salts. Atkinson teaches that suitable polymeric polycarboxylate crystal-growth modifiers include “ethylene/maleic acid copolymers, for examples, the EMA (Trade Mark) series ex Monsanto” (Atkinson col. 5). Atkinson further teaches that the polymeric polycarboxylate is incorporated into the aqueous slurry prior to crystallization so as to influence crystal growth and produce modified crystal morphology, teaching use of a maleic-acid-containing crystal-growth-modifying copolymer having ethylene-derived, non-carboxylated hydrocarbon repeating units incorporated into the polymer backbone.
Greene further clarifies the composition of the Monsanto EMA polymer family identified by Atkinson. Greene teaches that “(a) preferred structuring agent of the present invention is the 1:1 copolymer of ethylene with maleic anhydride” and identifies Monsanto EMA-21 as a particularly preferred ethylene maleic anhydride copolymer, with EMA-22 and EMA-24 identified as the acid and sodium-salt forms, respectively, of EMA-21, confirming that Monsanto EMA polymers references by Atkinson contain ethylene-derived repeating units in a maleic-acid/maleic anhydride polymer backbone.
Amick is directed to stabilizing aqueous systems containing scale-forming salts and inorganic particulates through addition of water-soluble polymers. Amick teaches that anti-precipitation may occur by “adsorption of the inhibitor onto the salt crystal soon after nucleation, thereby interfering with further crystal growth” (Amick col. 1). Amick further teaches that adsorption into precipitated salt crystals imparts an electronegative charge that retards agglomeration, settling, and deposition on surfaces, teaching that adsorption onto forming mineral crystal surfaces during crystal growth is a known mechanism by which polymeric water-treatment inhibitors modify mineral precipitation and control scale formation.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide Yamaguchi’s maleic-acid-based water-treatment copolymer with the ethylene-derived non-carboxylated hydrocarbon repeating units taught by Atkinson and confirmed by Greene, and to use that copolymer for mineral crystal-growth modification through adsorption onto forming mineral crystal surfaces as taught by Amick. Yamaguchi teaches a maleic-acid-based polymer useful for water-treatment and antiscale applications; Atkinson teaches that ethylene/maleic acid copolymers were known polycarboxylate crystal-growth modifiers in aqueous inorganic salt systems; Greene confirms the ethylene-derived hydrocarbon repeating-unit structure of the referenced EMA polymers; and Amick explains the known adsorption-based mechanism by which polymeric inhibitors interact with forming salt crystals and interfere with further crystal growth. Therefore the recited increase in adsorption onto a forming mineral crystal surface during crystal growth would have been an expected functional property of employing the known ethylene/maleic-acid crystal-growth-modifying copolymer structure in Yamaguchi’s antiscale water-treatment context.
Regarding claim 22, Yamaguchi in view of Atkinson and Greene and further in view of Amick discloses or makes obvious the copolymer of claim 6, wherein said copolymer adsorbs onto a forming calcium carbonate crystal lattice and disrupts lattice propagation during crystal growth, thereby modifying crystal habit (Amick col. 1 teaches adsorption of a polymeric inhibitor onto a forming calcium carbonate crystal after nucleation and interference with continued crystal growth, which disrupts lattice propagation and modifies crystal habit).
Regarding claim 24, Yamaguchi in view of Atkinson and Greene and further in view of Amick discloses or makes obvious the copolymer of claim 6, wherein said copolymer modifies crystal habit of at least one scale-forming compound selected from calcium carbonate (Yamaguchi teaches in various examples testing the efficacy of the polymer as an anti-scale agent to modify the crystal habit of calcium carbonate), calcium sulfate, barium sulfate, calcium phosphate, calcium oxalate, silica, or silicates by adsorption onto a forming crystal lattice (Amick col. 1 teaches that the anti-precipitation operates possibly by adsorption of the inhibitor onto the salt crystal soon after nucleation).
Regarding claim 30, Yamaguchi in view of Atkinson and Greene and further in view of Amick discloses or makes obvious the copolymer of claim 6, wherein said copolymer maintains dispersion of modified mineral precipitates in an aqueous phase by electrostatic repulsion between polymer-coated precipitates (Amick col. 1 teaches that “Dispersion of the precipitated salt crystals is another stabilization mechanism believed to be the result of the adsorption of the inhibitor onto precipitated crystals, thereby imparting an electronegative charge which retards agglomeration, settling and deposition on surfaces by repulsive forces” teaching that polymer-coated modified mineral precipitates maintained in aqueous dispersion by electrostatic repulsion between the charged, polymer-coated precipitates).
Claims 23, 26 and 28-29 are rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (US 5135677) as applied to claim 6 above, and further in view of Austin (US5866012).
Regarding claim 23, Yamaguchi discloses the copolymer of claim 6, and further teaches the polymer for use as a superior water-treating agent and detergent additive for the industrial field (Yamaguchi abstract).
Yamaguchi does not expressly disclose that the copolymer alters crystal morphology of precipitating mineral scale such that adhesion of the precipitated mineral scale to metal or pipe interior surfaces is reduced.
Austin ‘012 is directed to maleate copolymers used in water-treatment systems to modify crystal formation and inhibit scale formation. In Example 2, Austin ‘012 tests its maleate copolymer in calcium-carbonate-forming aqueous solutions and evaluates the resulting precipitated crystals by scanning electron microscopy. Austin ‘012 teaches that treatment with its maleate copolymer significantly distorted crystal morphology, creating crystals having narrow points of attachment to nucleation sites, and further states that the small attachment site is believed to create mechanical instability and thereby inhibit scale deposition. Austin ‘012 therefore teaches that a maleate water-treatment copolymer alters the morphology of precipitating mineral scale so that the resulting crystals have reduced attachment and reduced deposition onto receiving surfaces, which corresponds to reduced adhesion of precipitated mineral scale to metal or pipe interior surfaces.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to use Yamaguchi’s maleic-acid-based antiscale copolymer to alter precipitating mineral-scale morphology so as to reduce adhesion to metal or pipe interior surfaces, as taught by Austin ‘012. Yamaguchi teaches an acid-type maleic acid polymer/copolymer useful as a water-treatment antiscale agent, while Austin ‘012 teaches in the same water-treatment and scale-control field that maleate copolymers alter calcium-carbonate crystal morphology to produce mechanically unstable crystals having narrow attachment points and inhibited scale deposition. One of ordinary skill would have been motivated to apply the known crystal-morphology-modifying behavior taught by Austin ‘012 to Yamaguchi’s maleic-acid antiscale copolymer in order to reduce deposition and adhesion of precipitated mineral scale on system surfaces, with a reasonable expectation of success.
Regarding claim 26, Yamaguchi in view of Austin ‘012 discloses the copolymer of claim 6, wherein said copolymer retains solubility and crystal habit modification functionality in aqueous systems having elevated calcium concentration and alkalinity due to electrostatic repulsion along the polymer backbone. (Austin ‘012 col. 2 teaches an aqueous-polymerized maleate copolymer having a nonionic monomer residue which is useful as “an antiscalant, an anti-incrustation agent, a dispersant, a Sequestrant and a water hardness salt (…) crystal modifier”. Austin ‘012 Example 2 further evaluates its Copolymer 1A in calcium-carbonate testing at high pH and high electrolyte conditions concluding that copolymers comprising a nonionic monomer provide better threshold inhibition, “dispersancy” and scale inhibition under high electrolyte and pH conditions. Because the copolymer rendered obvious by Yamaguchi and Austin ‘012 was a water-soluble, carboxylate-containing maleate copolymer shown by Austin ‘012 to retain calcium-carbonate scale-control and crystal-modifying functionality under high-pH/high-electrolyte aqueous conditions, the stability and retained functionality attributable to electrostatic repulsion along the charged carboxylate-containing polymer backbone would have been an expected property of the same copolymer under the recited elevated-calcium and alkaline conditions).
Regarding claim 28, Yamaguchi in view of Austin ‘012 discloses the copolymer of claim 6, wherein said copolymer provides crystal habit modification, sequestration, and dispersion functionality in an aqueous system as a result of the combined presence of carboxylated repeating units and non-ionic repeating units along the polymer backbone (Austin ‘012 abstract teaches maleate copolymers comprising from about 40 to 70 mole percent of dicarboxylic functionality, from about 1 to 15 mole percent of the polymerized residue of a non-ionic monomer and from about 20 to about 50 mole percent of monocarboxylic functionality, further teaching that the resulting copolymer is useful as an antiscalant, an anti-incrustation agent, a dispersant, a Sequestrant and a water hardness salt (…) crystal modifier and concludes that the copolymers comprising a nonionic monomer (e.g., acrylamide) provide better threshold inhibition, “dispersancy” and scale inhibition that a 50/50 molar ratio maleate/acrylate copolymer and the commercial polymer controls. From these teachings a person of ordinary skill in the art would conclude that the combined presence of carboxylated repeating units and nonionic repeating units in a maleate copolymer provides crystal modification, sequestration, and dispersion functionality in an aqueous water-treatment system).
Regarding claim 29, Yamaguchi in view of Austin ‘012 discloses the copolymer of claim 6, wherein said copolymer forms precipitated mineral structures having reduced planar surface area relative to untreated calcite (Austin ’012 col. 11 teaches precipitating calcium carbonate in aqueous solutions treated with its maleate copolymer and examining the resulting crystals by scanning electron microscopy. Austin ‘012 discloses that treatment with its copolymer Significantly distorted crystal morphology, creating crystals having narrow points of attachment to nucleation sites and that the small attachment site is believed to create mechanical instability and thereby inhibit scale deposition).
Claim 31 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (US5135677) and further in view of Austin (US5866012) and Amjad, "The Use of Polymers to Improve Control of Calcium Carbonate Scaling in High Stressed Cooling Water Systems-Part II".
Regarding claim 31, Yamaguchi discloses a copolymer comprising: maleic acid monomer units (Yamaguchi abstract “acid-type polymaleic acid and acid-type maleic acid copolymer” are built by polymerizing maleic acid so maleic acid monomer units are integral to the polymer backbone), mono-carboxylic acids (Yamaguchi col. 5 lines 64-67), terminal hydroxyl groups (Yamaguchi col. 5 lines 19-21, isoprenol, prenol, isoprene alcohol and by example of formula 1 each possessing terminal hydroxyl groups), non-ionic functional groups which aid in adsorption onto a crystal surface (Yamaguchi’s terminal hydroxyl groups constitute non-ionic functional groups, and the adsorption-related functionality is an expected property of using such non-ionic hydroxyl containing polymer in Yamaguchi’s disclosed water-treatment/antiscale application), wherein said non-ionic functional groups and said terminal hydroxyl groups are formed during an aqueous polymerization process (Yamaguchi col. 9 lines 12-14), so that said copolymer comprises at least approximately 50 molar% maleic acid and up to 50 molar% of free radical polymerized comonomers (Yamaguchi col. 4 “50-99.9 wt. % of maleic acid (A) and 50-0.1 wt. % of other water-soluble unsaturated monomer (B)”), further teaching the claimed water-treatment context because of the resulting acid-type maleic acid polymer is described as useful as a water-treating agent (Yamaguchi abstract).
Yamaguchi does not expressly disclose that the polymer includes at least 5 molar% decarboxylated maleic acid repeating units, or that the copolymer adsorbs onto forming calcium carbonate crystals and promotes formation of rounded or spherical precipitated calcium carbonate structures rather than cubic calcite precipitates. Yamaguchi nevertheless teaches that the polymerization evolves carbon dioxide, presumably as the result of decarbonization from the maleic acid and/or acid-type maleic acid polymer present in the polymerization system and that it is possible to control the amount of decarbonization by controlling the amount of hydrogen peroxide to be added. Thus, as set forth in the rejection of claim 6 above and response to Applicant’s arguments, selection of a decarboxylation amount meeting the claimed minimum of at least 5 molar% would have been an obvious optimization of Yamaguchi’s expressly controllable polymerization process.
Austin ‘012 is directed to water-soluble maleate copolymers prepared by aqueous solution polymerization and used to sequester water-hardness ions, modify crystal formation in water, and inhibit scale formation. Austin ‘012 teaches a maleate copolymer comprising maleate functionality, monocarboxylic functionality, and non-ionic monomer residue, preferably prepared with about 40 to 70 mole percent maleate monomer, about 20 to 50 mole percent carboxylic-acid monomer, and about 1 to 15 mole percent non-ionic comonomer, such as acrylamide or vinyl acetate. Austin ‘012 further teaches that the resulting copolymer us useful as a water-hardness-salt-crystal modifier, expressly including calcium carbonate, and may be used to “modify crystal formation in water and inhibit scale formation” (Austin ‘012 abstract). Austin ‘012 further teaches the calcium-carbonate crystal-modification result. In Example 2, Austin ‘012 evaluates calcium-carbonate crystals formed after treatment with an inventive maleate terpolymer prepared from maleic acid, acrylic acid, and acrylamide, in comparison with control polymers. Austin ‘012 teaches that the inventive copolymer significantly distorted the calcium-carbonate crystal morphology and created crystals having narrow points of attachment to nucleation sites, while the comparative polymers exhibited traditional calcite and aragonite morphology.
Amjad is directed to controlling calcium-carbonate scaling in high-stress cooling water systems using polymer-containing inhibitor treatments. Amjad teaches calcium-carbonate precipitation testing under high-stress cooling-water conditions, followed by X-ray diffraction and scanning electron microscopy analysis of the collected precipitate. Amjad concludes that, compared with the untreated control, the inhibited system calcium-carbonate crystals were “significantly distorted with spherical shapes” (p 4 and 6), more readily dispersed and less likely to adhere to heat exchanger surfaces, and were all calcite, whereas the untreated crystals were primarily calcite with some aragonite.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to provide the acid-type maleic acid copolymer of Yamaguchi, having an optimized decarboxylation content as discussed above, with the known calcium-carbonate crystal-modification functionality taught by Austin ‘012 and Amjad. Yamaguchi teaches a maleic-acid-based copolymer formed in aqueous solution and useful as a water-treatment agent; Austin ‘012 teaches that closely related aqueous-polymerized maleate copolymers containing monocarboxylic and non-ionic functionality are useful calcium-carbonate crystal modifiers that distort ordinary calcite morphology and inhibit scale deposition; and Amjad teaches that polymer-containing calcium-carbonate scale-control treatments produce significantly distorted spherical calcite crystals rather than conventional untreated crystal morphology. The references therefore, collectively provide motivation to employ Yamaguchi’s water-treatment copolymer for calcium-carbonate crystal-habit modification with the expectation that ordinary cubic calcite precipitation would be altered toward rounded or spherical precipitate morphology.
Conclusion
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/W.A.G./Examiner, Art Unit 1779
/Bobby Ramdhanie/Supervisory Patent Examiner, Art Unit 1779
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