Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined pursuant to the first inventor to file provisions of the AIA .
DETAILED ACTION
Status of the Claims
The Examiner acknowledges receipt of Applicants’ Response, filed 16 February 2026. Claims 1, 12, and 17 are amended therein, and claims 7, 8, 11, and 21 are cancelled. Accordingly, claims 1, 2, 9, 10, 12, 14 – 18, 20, and 22 remain available for active consideration.
REJECTIONS WITHDRAWN
Rejections Pursuant to 35 U.S.C. § 103
The obviousness rejections set forth in the Action of 18 November 2025 are hereby withdrawn in light of Applicants’ amendment of the claims, and in favor of the new grounds of rejection set forth below.
NEW GROUNDS OF REJECTION
Rejections Pursuant to 35 U.S.C. § 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.
Independent claims 1 and 17, and claims 2, 9, 10, 12, 14 – 18, 20, and 22, dependent therefrom, are rejected pursuant to 35 U.S.C. § 112(b), as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Claim 1 recites a newly added limitation directed to the average diameter of the plurality of particles being greater than 400 nm and less than 5 µm.
Claim 12 recites a limitation directed to the plurality of particles having an average diameter of 400 nm to 1 µm.
The claims are indefinite because one of ordinary skill in the art would be uncertain as to whether the numerical size limitations apply to the plurality of particles as a whole or to each one of the particles in the plurality of particles. Appropriate correction or cancelation is necessary. If Applicants elect to further amend the claims to address this issue, the Examiner would suggest that Applicants amend the claims to recite “an average diameter of each particle in the plurality of particles.”
Claim 17 recites a limitation directed to the “average diameter of the particles is greater than 400 nm and less than 5 µm.” There is no antecedent basis for the recitation of “the particles.” Appropriate correction or cancelation is necessary.
Rejections Pursuant to 35 U.S.C. § 103
The following is a quotation of 35 U.S.C. § 103 that 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.
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 absent any evidence to the contrary. Applicants are advised of the obligation pursuant to 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, 2, 9, 10, 12, 14 – 18, 20, and 22 are rejected pursuant to 35 U.S.C. § 103, as being obvious over US 2006/0193882 A1 to Botts, M., et al., published 31 August 2006, identified on the Information Disclosure Statement (IDS) filed 23 June 2022, cite no. 1 (USPATAPP) (“Botts ‘882”), in view of Hornig, S. and T. Heinze, Biomacromolecules 9: 1487 – 1492 (2008) (“Hornig (2008)”), Dai, R., et al., Colloids and Surfaces A 530: 13 – 19 (2017) (“Dai (2017)”), Buchanan, C., et al., Journal of Applied Polymer Science 47: 1709 - 1719 (1993) (“Buchanan (1993)”), and WO 2017/202684 A1 to Faers, M., et al., published 30 November 2017 (“Faers WO ‘684”).
The Invention As Claimed
Applicants claim a method of treating a plant, the method comprising the step of applying a suspension comprising an aqueous medium, and a plurality of particles dispersed throughout the aqueous medium, to a surface of the plant, wherein each particle in the plurality of particles includes a polymeric carrier material and active ingredient dispersed throughout the particles, wherein the polymeric carrier material is a cellulose acetate having an average molecular weight, Mn, of 30,000 Daltons to 50,000 Daltons, and a degree of substitution from 2.45 to 2.85, wherein the suspension has a zeta potential value of -30 mV to -40 mV, and wherein the polymeric carrier material has an interfacial tension in the range of 70 – 25 dynes/cm, and wherein the active ingredient can be released at a continuous rate of 40 - 68% over a period of 24 hours, wherein the active ingredient comprises fluopyram, and wherein an average diameter of the plurality of particles is greater than 400 nm and less than 5 µm, wherein the polymeric carrier material degrades by at least 90% in two years, wherein the plurality of particles comprise less than about 20% wgt of polymeric carrier material, or 0.1 to 10% wgt of polymeric carrier material, wherein the particles have an average diameter of 400 nm to 1 µm, wherein the suspension further comprises no more than 1% vol organic solvent, wherein the plurality of particles adhere at least 40% of an initial amount after being subjected to 5 min of continuous water flow, and wherein the plurality of particles further comprise 0.005 to 2% wgt surfactant.
Applicants also claim a method of making a suspension, the method comprising adding polymer material to an organic solvent such that the polymer material is present in the organic solvent at a concentration less than 20% wgt, wherein the polymer material is a cellulose acetate having an average molecular weight, Mn, of 30,000 - 50,000 Da, and a degree of substitution of 2.45 - 2. 85, adding an active ingredient to the organic solvent such that the active ingredient is present in the organic solvent at a concentration of 0.001 wt.% to 0.015 wt.%, wherein the active comprises fluopyram, agitating the organic solvent with the polymer material and the active ingredient, adding aqueous media to the organic solvent mixture in doses, each dose volume being no more than 5 vol% (or 1 vol.%) of the total organic solvent mixture volume, and removing the organic solvent, wherein the aqueous suspension comprises no more than 1 % by volume organic solvent, and wherein the particles include less than 20% wgt of the polymer material.
The Teachings of the Cited Art
Botts ‘882 discloses one or more agricultural active ingredients (such as fungicides) that are entrapped in polymeric matrixes to form particles having diameters in the range from about 0.2 to about 200 µm, wherein the particles are applied to plants, and release the active ingredients at a rate sufficiently low to avoid phytoxicity, but at a rate sufficiently high to provide effective amounts of the active ingredients (see Abstract), wherein controlled release of a pesticide has been used in the art as a method of controlling the phytotoxicity of pesticides to the plant species (see ¶[0006]), wherein controlled release formulations comprising these particles provide a means by which an agricultural chemical, such as a fungicide, can be delivered to a plant over the entire growing season at a concentration or rate that is agronomically effective, while reducing plant phytotoxicity relative to current commercially used formulations (see ¶[0016]), wherein a controlled-release formulation that comprises particles in which one or more agricultural active ingredients are dispersed in a polymeric matrix are safe when applied to plants even though they contain levels of active ingredients that would be phytotoxic if applied to the plants in standard fast-release formulations, wherein the particles can release at least one active ingredient at biocidally beneficial levels over a period during the germination and growth of an agriculturally beneficial plant (e.g., for at least two to twelve weeks, or more) and therefore can reduce or eliminate the need for subsequent applications of the agricultural chemical, wherein the rate of release of agricultural chemicals, and the period over which effective amounts of such chemicals can be released, can be tailored as desired such that the formulations increase the period during which an agricultural chemical is effective, reduce the initial toxicity of the chemical to seeds or crop plants, expand the range of compounds that can be used for agricultural applications, and decrease the environmental impact of chemical treatment (see ¶[0018]), wherein the particles have an average diameter of about 100 nm to about 200 µm, the particles each comprising a polymer matrix and at least one agricultural chemical distributed throughout the polymer matrix, the particles including about 1 to about 50% wgt of the agricultural chemical and about 50 to about 99% wgt of the polymer matrix (see ¶[0020]), wherein the compositions are in the form of suspensions of polymeric particles in an aqueous medium, and the particles adhere to surfaces of a plant (see ¶[0021]), wherein the particles are used in a method for the treatment or prophylaxis of a fungal disease in a target plant wherein the method comprises contacting a plant or plant tissue with a particle comprising a fungicide in a polymer matrix, and wherein, after the contacting, the health of the target plant is substantially similar to the health of a control plant which is substantially free of the fungal disease and which is free of contact with the fungicide (see ¶[0023]), wherein the polymer used in the compositions comprises cellulose derivatives such as cellulose acetate butyrate and cellulose acetate phthalate, among others (see ¶[0026]), wherein the particles are prepared by a method comprising dissolving an agricultural chemical (for example, a fungicide) and a polymer to form a hydrophobic solution, mixing the hydrophobic solution and an aqueous medium at a shear rate and for a time period sufficient to produce an emulsion having droplets of the hydrophobic solution dispersed in the aqueous medium, and evaporating the organic solvent from the emulsion to produce a plurality of particles with the agricultural chemical distributed throughout the polymer, and further dissolving a dispersing agent [surfactant] in an aqueous solution to produce the hydrophilic solution to result in a suspension of the particles in the aqueous medium (see ¶[0030]; see also, ¶¶[0146], [0149]), wherein, in an exemplified embodiment, 3.72 g of a fungicide and 14.3 g of a polymer [8.2% wgt] are dissolved in 156 g methylene chloride in a glass bottle with shaking to produce the hydrophobic solution (see ¶[0177]), wherein the agriculturally active ingredient comprises about 1.0% to about 50% wgt of the particle, and from about 50 to about 99% wgt of the matrix material (see ¶[0064]), wherein the particles, when used in the form of a suspension in an aqueous carrier, comprise a dispersing agent, in the amount of 0.25 – 1.0%, to permit a relatively uniform or homogeneous mixture to form (see ¶[0149]), and wherein the particle formulation can be applied to a plant by any conventional method including application as a foliar spray, in a sufficient volume to thoroughly wet the foliage (see ¶[0171]). The reference does not disclose a cellulose acetate polymeric carrier material with an average molecular weight, Mn, of 30,000 Daltons to 50,000 Daltons, and a degree of substitution from 2.45 to 2.85, wherein the suspension has a zeta potential value of -30 mV to -40 mV, wherein the particles in the suspension have an interfacial tension in the range of 70 – 25 dynes/cm, or use of a polymeric carrier material that degrades by at least 90% in two years. The teachings of Hornig (2008), Dai (2017), Buchanan (1993), and Faers WO ‘684 remedy these deficiencies.
Hornig (2008) discloses commercially prepared cellulose acetate, cellulose acetate propionate, -butyrate, and -phthalate with varying degrees of substitution (DS) that self-assemble into regular nanoparticles, wherein the stability of suspensions comprising the nanoparticles in a physiological pH range was observed by zeta potential measurements (see Abstract), wherein the cellulose acetates had degrees of substitution (DS) between 1.65 and 3.00 and weight average molecular weights (Mw) from 26,100 to 131, 600 g/mol (see Table 1, p. 1488, 2nd col.), wherein deacetylation of CA to a degree of substitution (DS) of 2.46 results in degradation of the polymer backbone to a certain extent and, thus, in lower Mw in a range from 26,100 to 103,600 g/mol (see p. 1488, 2nd col., 2nd para.), wherein, without stabilizing agents, undesired aggregation of the polymeric nanoparticles through the formation of inter- and intra-molecular hydrogen bonds and van der Waals forces can occur (see p. 1487, 2nd col., 2nd para.), wherein zeta potentials of the nanoparticles were determined by dynamic light scattering (see p. 1488, 1st col., 1st para.), wherein, in an exemplified embodiment, suspensions of particles of cellulose acetate are produced by preparing a dilute solution of cellulose acetate in acetone (20 mg in 5 mL), wherein water (a non-solvent) was added dropwise to 15 mL of the polymer solution, and the resulting mixture was stirred at 60° C until the acetone was completely removed from the aqueous suspension (see p. 1488, 1st col., last para.), wherein embodiments utilized cellulose acetates with degrees of substitution from 1.65 to 3.00, and weight average molecular weights from 26 to 132 kDa (see Table 1, p. 1488, 2nd col.), wherein particles displayed sizes in the range of 166 – 399242 nm (see p. 1489, 1st col., 2nd para.), wherein investigations into stability revealed that no significant change could be observed by dynamic light scattering (DLS) after 1.5 years storage of suspensions for a pH range of 3.4 to 10 (see p. 1490, 2nd col., 4th para.), wherein, in general, suspensions with a zeta potential above ±30 mV are physically stable, and embodiments comprising cellulose acetate in deionized water exhibited a zeta potential of -39.6 mV, with stability maintained until pH of 3.4 and a zeta potential of -8.3 mV is reached (see p. 1491, 1st col., 1st para.), and wherein the stability of the nanoparticle suspensions is an important prerequisite for applications of these nanoparticles, such as for drug delivery devices (see p. 1491, 2nd col. 1st para.).
Dai (2017) discloses that the sustainable-release properties and spreadability of a microencapsulated pesticide, chlorpyrifos (O,O-diethyl O-(3,5,6,-trichloro-2-pyridyl phosphorothioate)), on rice blades are related to the utilization of the pesticide, and a surfactant (polysiloxane sodium carboxylate) was included to improve the spreadability of the microcapsules on the blades, and the capsules displayed high spreadability, which promotes increasing the residual amount of the capsules on hydrophobic blades, thereby improving the utilization of an encapsulated insecticide (see Abstract), wherein the surface tension (σ) of an aqueous solution of the encapsulating polymer (sodium carboxy methylcellulose) with different surfactants was tested (see p. 14, 2nd col., 7th para.), wherein addition of the surfactant causes a rapid decrease in the surface tension of the encapsulating polymer solution, while the amount of the polymer adsorbed onto the oil-water interface increased and, in specific embodiments, the surface tension was 19.31 mN/m [dynes] or 39.68 mN/m, depending on the surfactant used (see p. 15, 2nd col., 1st para.; see also, Fig. 1), wherein particle sizes of the microcapsules were in the range of about 1 to about 6 µm (see Fig. 5, p. 17), and wherein the contact angle was measured in order to prove that the microcapsules displayed good spreadability behavior such that, as spreadability improved, the residual amount of microcapsules on the blades increased, resulting in higher utilization of the encapsulated insecticide (see p. 18, 2nd col., 2nd para.; see also Fig. 9).
Buchanan (1993) discloses results from an evaluation of the biodegradation potential of cellulose acetate in an in vitro cultivation (closed batch) system, wherein microscopic examination revealed extensive degradation of the cellulose acetate (degree of substation at 2.5) after 2 - 3 weeks of incubation, wherein, for cellulose acetate with a degree of substitution of 1.7, films were able to degrade > 80% of the polymer in 4 - 5 days, compared 10 – 12 days for the cellulose acetate with a degree of substitution of 2.5 (see Abstract).
Faers WO ‘684 discloses agrochemical compositions based on emulsion polymers, their use for foliar application and their application in aqueous crop protection flowable formulations for controlling agricultural pests, weeds or diseases and reducing the wash-off of active ingredients by rainfall (see p. 1, ll. 2 – 4), wherein the biological efficacy of pesticides is influenced by many factors, particularly the residence time of the pesticide on the treated surface, which is often a plant leaf surface, where a major factor influencing the residence time is the degree to which the pesticide resists wash-off by rain, that is, rainfastness, which can be improved in aqueous dispersions by including ingredients in the formulation that, during drying, provide a water-resistant bond between the pesticide and the substrate, such as, for example, water insoluble polymers prepared as emulsions that improve liquid formulation rainfastness (see p. 1, ll. 5 – 11), wherein rainfastness is defined as the percentage of active ingredient that remains on the crop after rainfall or irrigation (see p. 1, ll. 13 – 16), wherein the compositions are in the form of highly storage-stable aqueous pesticide concentrates having no organic solvents, or solvent amounts sufficient only to dissolve a crystalline pesticide in the form of an emulsion, and which can be diluted easily with pure water, thereby forming stable dilute emulsions for application purposes (see p. 2, ll. 26 – 29), wherein rainfastness leads to a long-lasting activity of the active ingredient(s) under adverse weather conditions such as rain or wind, allowing a lower dose of active ingredient to be applied with minimal loss of performance and/or allowing for longer intervals between spray applications, such that low dose application of active ingredient and/or with longer spray intervals leads to improved crop safety and reduced phytotoxicity (see p. 3, ll. 6 – 10), wherein the compositions comprise an aqueous dispersion of at least one agrochemically active compound that is solid at room temperature, an emulsion polymer system comprising a stabilizer polymer and a core/stabilizer copolymer, one or more additives selected from the group consisting of non-ionic or anionic surfactants or other dispersing aids, rheological modifiers, and other formulants (see p. 3. ll. 23 – 33), wherein the compositions are used for foliar application (see p. 4, ll. 3 – 4), wherein use of the compositions leads to improvement in the rainfastness of the agrochemically active ingredient, as well as the resistance to wash-off by rain of the active ingredient (see p. 4, ll. 10 – 12), wherein agrochemically active ingredients comprise fungicides (see p. 4, ll. 23 – 24), wherein preferred fungicides include fluopyram (see p. 5, ll. 11 – 12), and wherein the core polymer comprises a natural polymer and derivatives thereof (see p. 11, l. 10), such as cellulose and/or acetyl cellulose [cellulose acetate] (see p. 12, ll. 27 – 29).
Application of the Cited Art to the Claims
It would have been prima facie obvious before the filing date of the claimed invention to prepare formulations comprising one or more agricultural active ingredients (such as fungicides or insecticides) that are entrapped in polymeric matrixes in the form of particles having diameters in the range from about 0.1 to about 200 µm, wherein the particles are applied to plants, and release the active ingredients at a rate sufficiently low to avoid phytoxicity, but at a rate sufficiently high to provide effective amounts of the active ingredients, wherein the particles can release the active ingredient at biocidally beneficial levels over a period during the germination and growth of an agriculturally beneficial plant (e.g., for at least two to twelve weeks, or more), wherein the particles include about 1 to about 50% wgt of the agricultural chemical and about 50 to about 99% wgt of the polymer matrix, wherein, when applied, the particles adhere to surfaces of a plant, wherein the polymer used in the compositions comprises cellulose derivatives such as cellulose acetate butyrate and cellulose acetate phthalate, among others, wherein the particles are prepared by a method comprising dissolving an agricultural chemical (for example, a fungicide) and a polymer in a suitable organic solvent to form a hydrophobic solution, mixing the hydrophobic solution with an aqueous medium to produce an emulsion having droplets of the hydrophobic solution dispersed in the aqueous medium, and evaporating the organic solvent from the emulsion to produce a plurality of particles with the agricultural chemical distributed throughout the polymer, and further dissolving a dispersing agent in the aqueous solution to produce the hydrophilic solution, resulting in a suspension of the particles in the aqueous medium, wherein, specifically, 3.72 g of a fungicide and 14.3 g of a polymer [8.2% wgt] are dissolved in 156 g methylene chloride in a glass bottle with shaking to produce the hydrophobic solution, wherein the particles, when used in the form of a suspension in an aqueous carrier, comprise a dispersing agent/surfactant, in the amount of 0.25 – 1.0%, to permit a relatively uniform or homogeneous distribution to form, and wherein the particle formulation can be applied to a plant by any conventional method including application as a foliar spray, in a sufficient volume to thoroughly wet the foliage, as taught by Botts ‘882, wherein the stability of suspensions comprising the nanoparticles in a physiological pH range was assessed by zeta potential measurements, wherein zeta potentials of the nanoparticles were determined by dynamic light scattering, wherein embodiments utilized cellulose acetates with degrees of substitution from 1.65 to 3.00, and weight average molecular weights from 26 to 132 kDa, wherein investigations into stability revealed that no significant change could be observed by dynamic light scattering (DLS) after 1.5 years storage of suspensions for a pH range of 3.4 to 10 (see p. 1490, 2nd col., 4th para.), wherein embodiments exhibit a zeta potential of -39.6 mV, with stability maintained until pH of 3.4 and a zeta potential of -8.3 mV is reached, and wherein cellulose acetate particles were prepared by adding water (a non-solvent) dropwise to the polymer solution, and stirring the resulting mixture at 60° C until the acetone was completely removed from the aqueous suspension, as taught by Hornig (2008), and wherein the capsules displayed high spreadability, which promotes an increase in the residual amount of the capsules on hydrophobic blades, thereby improving the utilization of an encapsulated active, wherein addition of the surfactant causes a rapid decrease in the surface tension of the encapsulating polymer solution, while the amount of the polymer adsorbed onto the oil-water interface increased and, in specific embodiments, the surface tension was 19.31 mN/m [dynes] or 39.68 mN/m, depending on the surfactant used (see p. 15, 2nd col., 1st para.; see also, Fig. 1), and wherein the contact angle was measured in order to prove that the microcapsules displayed good spreadability behavior such that, as spreadability improved, the residual amount of microcapsules on the blades increased, resulting in higher utilization of the encapsulated insecticide, as taught by Dai (2017), wherein microscopic examination of treated plants revealed extensive degradation of the cellulose acetate (degree of substation at 2.5) after 2 - 3 weeks of incubation, wherein, for cellulose acetate with a degree of substitution of 1.7, films were able to degrade > 80% of the polymer in 4 - 5 days, compared 10 – 12 days for the cellulose acetate with a degree of substitution of 2.5, as taught by Buchanan (1993), and wherein the fungicide is fluopyram, and wherein rainfastness, the degree to which the pesticide resists wash-off by rain, can be improved in aqueous dispersions by including ingredients in the formulation that, during drying, provide a water-resistant bond between the pesticide and the substrate, such as, for example, water insoluble polymers prepared as emulsions that improve liquid formulation, the polymers comprising cellulose acetate, as taught by Faers WO ‘684.
One of ordinary skill in the art would be motivated to do so, with a reasonable expectation in so doing, by the express teachings of Hornig (2008) to the effect that stability of the nanoparticle suspensions is an important prerequisite for applications of these nanoparticles, such as for drug delivery devices, and that investigations into stability revealed that no significant change could be observed by dynamic light scattering (DLS) after 1.5 years storage of suspensions for a pH range of 3.4 to 10, by the teachings of Dai (2017) to the effect that high spreadability promotes increases in the residual amount of the capsules on hydrophobic blades, thereby improving the utilization of the encapsulated insecticide, by the express disclosures of Buchanan (1993) to the effect that the degree of acyl substitution directly effects the degradation rate of cellulose acetate, and by the explicit disclosures of Faers WO ‘684 to the effect that polymer emulsion compositions comprising fluopyram in cellulose acetate exhibit enhanced rainfastness, and can be applied, consequently at lower doses of the active, and/or at longer application intervals (see p. 3, ll. 6 – 10).
With respect to claims reciting quantitative limitations (see claim 1 - degree of substitution, molecular weight/zeta potential/interfacial tension; see claims 9, 10 - relative loadings; see claims 11, 12 - average diameters), the Examiner notes that the particles of the cited art are prepared with quantitative characteristics that are not exactly congruent with the claimed ranges. However, it is the Examiner’s position that the cited art teaches a range of quantitative characteristics that significantly overlaps with the claimed ranges and, as such, would render the claimed invention obvious. See MPEP § 2144.05. “In the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976).”
With respect to claim 14, directed to a residual solvent content of “no more than 1% by volume of the solvent,” the Examiner notes that the cited art does not expressly disclose quantitative levels of residual solvents. However, the Examiner further notes that Botts ‘882 disclose methods for preparation of the particle formulations that comprise solvent evaporation techniques (see ¶¶[0030] – [0032]), wherein the solvent is removed from the dispersion comprising the particles. Furthermore, the reference discloses that “all of the solvent” is evaporated from the suspensions (see ¶[0156]), thus reading on the limitation at issue.
With respect to claim 22, which claim recites a limitation directed to aqueous media being added to the hydrophobic solution comprising polymer and active in doses in volumes “being no more than 1 wt%” of the hydrophobic solution, the Examiner notes that the cited references do not specifically disclose a mixing step wherein the aqueous component is added to the hydrophobic phase (polymer/active/solvent) in increments expressed as relative per cents. However, the Examiner notes that Hornig (2008) discloses the mixing of an acetone solution of cellulose acetate by adding distilled water dropwise to the polymer solution, followed by evaporation of the organic solvent at 60° C. Acknowledging that the volume of a single drop of water is highly likely to amount to less than 1% of the volume of the cellulose acetate solution, this disclosure reads on the limitation in question.
In light of the forgoing discussion, the Examiner concludes that the subject matter defined by claims 1, 2, 9, 10, 12, 14 – 18, 20, and 22 would have been obvious within the meaning of 35 USC § 103.
Response to Applicants’ Arguments
The Examiner has considered the arguments presented by Applicants in the Response filed 16 February 2026, but does not find them persuasive. The primary thrust of Applicants’ arguments is directed to the alleged distinction between number-average molecular weight (Mn) and weight-average molecular weight (Mw). Applicants argue that the molecular weights for cellulose acetate polymers as disclosed in Hornig (2008) are weight-average molecular weights (Mw), and not number-average molecular weights (Mn) as recited in claim 1 (“Hornig discloses weight-average molecular weight (Mw), which is a fundamentally different parameter from the number-average molecular weight (Mn) recited in the claims.”).
Applicants correctly point to the differences between the two types of molecular weights, and state further that “the two values are not interchangeable absent disclosure of the molecular weight distribution.” What Applicants’ argument fails to take into consideration is that Hornig (2008) discloses data that permits a conversion between weight-average molecular weights and number-average molecular weights. In Table 1 (p. 1488), the reference provides data for various cellulose acetate polymers. Two of these polymers have degrees of substitution that read on the limitation recited in claim 1 (2.45 – 2.85). These polymers have a DS of 2.46, and a corresponding Mw of 131,600 g/mol, and a DS of 2.72,with a corresponding Mw of 67,400 g/mol. The reference also discloses Polydispersity Index (PDI) values for various cellulose acetate particle distributions (see Table 2, p. 1489). One of these values is for cellulose acetate particles formed by dropwise addition of water to a dilute solution of the polymer in acetone, the same preparation method used in the primary obviousness reference, Botts ‘882, and which produces different results than when an acetone solution of cellulose acetate is added to water. The PDI for this particle distribution is disclosed in Table 2 as 0.230, indicating a broad particle size distribution for the polymer with a DS of 2.46 (see p. 1490, 2nd col., 1st para.).
Given that the PDI is, in effect, an indicator of the particle size distribution, it can be used to calculate a number-average molecular weight from a weight-average molecular weight. As evidenced by Whitfield, R., et al., Chem. Sci. 10: 8724 – 8734 (2019), the relationship can be expressed as PDI = Mw/Mn (see p. 8724, 2nd col., 1st para.). Thus, for a PDI of 0.230 (see Table 2), and a weight-average molecular weight of 131,600 g/mol (see Table 1), the number-average molecular weight is 30,268 g/mol, which is within the quantitative range recited in claim 1, rendering it prima facie obvious.
Applicants also argue that “Hornig does not teach incorporating an active ingredient in its methods.” However, the reference’s utility with respect to the rejection lies in the methods used to prepare distributions of nanoparticles of cellulose acetate, as the incorporation of an active into a nanoparticle is disclosed by Botts ‘882.
Applicants also argue that Faers WO ‘684 “does not disclose, teach, or suggest entrapping an active ingredient in a polymer matrix, as recited in claim 1.” However, the rejection of record does not cite this reference for the form of the disclosed composition, but for the fact that it discloses fluopyram as the preferred fungicide for foliar application in crop protection. The primary reference, Botts ‘882, teaches the incorporation of fungicides in polymer nanoparticles for foliar application, as cited in the rejection of record.
Consequently, based on the above discussion, Applicants’ arguments are unpersuasive, and claims 1, 2, 9, 10, 12, 14 – 18, 20, and 22 stand rejected pursuant to 35 U.S.C. § 103.
NO CLAIM IS ALLOWED.
Applicants’ amendment necessitated the new ground of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicants are 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.
CONCLUSION
Any inquiry concerning this communication or any other communications from the Examiner should be directed to Daniel F. Coughlin whose telephone number is (571)270-3748. The Examiner can normally be reached on M - F 8:30 a.m. - 5:00 p.m.
If attempts to reach the Examiner by telephone are unsuccessful, the Examiner’s supervisor, David Blanchard, can be reached on (571)272-0827. The fax phone number for the organization where this application or proceeding is assigned is (571)273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see <http://pair-direct.uspto.gov>. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
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.
/DANIEL F COUGHLIN/
Examiner, Art Unit 1619
/DAVID J BLANCHARD/ Supervisory Patent Examiner, Art Unit 1619