DETAILED ACTION
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 .
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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN-102718588) in view of Wynnyk et al. (US Patent Publication No. 2004/0016276).
In regard to claim 1, Zhang teaches a controlled release fertilizer containing ammonium polyphosphate (e.g. composite fertilizer granules containing ammonium polyphosphate) [paras. 0016-0018], wherein:
the controlled release fertilizer comprises fertilizer core particles and fertilizer envelopes coated on a surface of the fertilizer core particles respectively (e.g. fertilizer granules are coated with powder and oil) [0018];
the fertilizer core particles contain phosphorus source, nitrogen source, potassium source and multiple metallic medium and trace element sources (e.g. potassium fertilizer, nitrogen fertilizer, and trace elements mixed with ammonium polyphosphate phosphorous source) [0017];
P (phosphorus) in the phosphorus source is only from ammonium polyphosphate which has a degree of polymerization in a range of 5 to 20 (e.g. ammonium polyphosphate with a degree of polymerization not greater than 10) [0016] and 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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) See MPEP 2144.05] and has a chelating effect on metallic medium and trace elements in the multiple metallic medium and trace element sources (e.g. ammonium polyphosphate can form completely water-soluble chelates with trace elements such as zinc and iron, which can simultaneously supplement phosphorus fertilizer and trace elements to plants) [0034].
Zhang discloses wherein the fertilizer envelopes include oil or powder (e.g. fertilizer granules are coated with powder and oil) [0018] but does not explicitly recite polyurethane envelopes.
Wynnyk et al. is directed to controlled release fertilizer material surrounded by a protective urethane-containing coating [abstract], typically polyurethane [0031]. Wynnyk et al. describe that it is known in the art to coat particulate plant nutrient with oil to improve the release profiles of the plant nutrient [0007]. Wynnyk describes polyurethane used to produce a coating that is less susceptible to damage during the mechanical handing of the fertilizer material [0020]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include a polyurethane coating (e.g. envelope) as a component of Zhang’s fertilizer product in addition to or in place of the oil coating disclosed. One of ordinary skill in the art would have been motivated to do so to improve controlled release of fertilizer nutrients [0020; 0005].
Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Walker (WO-2022133548) in view of Whittington (US Patent Publication No. 2005/0076687) and Wang et al. (ACS omega, 2021).
In regard to claim 1, Walker teaches a controlled release fertilizer (e.g. nutrients in the form that are sustained release) [pg. 14, lines 29-30] containing ammonium polyphosphate (e.g. phosphorous in the form of ammonium polyphosphate) [pg. 18, line 28], wherein:
the controlled release fertilizer comprises fertilizer core particles and fertilizer envelopes coated on a surface of the fertilizer core particles respectively (e.g. fertilizer granule particles can be coated) [pg. 17, lines 4-7];
the fertilizer core particles contain phosphorus source, nitrogen source, potassium source and multiple metallic medium and trace element sources (e.g. NPKS in addition to micronutrients including zinc, copper, iron, manganese, boron, molybdenum and secondary nutrients calcium, magnesium and silicon [pg. 19, last para.].
Walker discloses fertilizer envelopes coated on a surface of the fertilizer core particles respectively (e.g. fertilizer granule particles can be coated) [pg. 17, lines 4-7] but does not explicitly teach wherein the envelopes are polyurethane.
Whittington is directed to a method for coating fertilizer in pellet form with a polyurethane coating [abstract]. The polyurethane polymeric coating of Whittington is described as encapsulating fertilizer particles to form a hydrophobic coating that slowly releases plant nutrients from the fertilizer particle into the soil in response to moisture and temperature [0013].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to choose a polyurethane polymer coating as described by Whittington as the coating material for the granule particles of Walker. One of ordinary skill in the art would have been motivated to do so because where Walker describes the fertilizer coating generally as “a known coating that reduced the hydroscopic nature of the particles” and that the coating is intended to reduce any tendency to absorb water, which might affect the resultant crush strength [pg. 17, lines 6-9], the use of polyurethane as described by Whittington as forming a hydrophobic coating that slowly release plant nutrients from the fertilizer particle into the soil [0027] would have yielded predictable results. It would have been "obvious to try" a polyurethane coating as the coating of Walker where the prior art provides a general approach of coating fertilizer particles.
Walker does not explicitly disclose wherein the P (phosphorus) in the phosphorus source is only from ammonium polyphosphate which has a degree of polymerization in a range of 5 to 20.
Wang et al is directed to short-chain ammonium polyphosphate [abstract], wherein the degree of polymerization is in a range of 2 to 20 [pg. 18811, first col.]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize a short-chain ammonium polyphosphate as the ammonium polyphosphate material disclosed in Walker. One of ordinary skill in the art would have been motivated to do so because short-chain APPs are effective phosphate fertilizers and are known to increase soil P availability and improve phosphorus fertilizer use efficiency [pg. 18811, first col.]. Furthermore, Wang teaches a chelating effect on metallic medium and trace elements in the multiple metallic medium and trace element sources (e.g. poly-P fertilizers exhibit significant effects on mobilizing or activating soil recalcitrant P through chelating with soil metal ions such as Ca2+, Mg2+, Fe3+, and Al3+) [pg. 18811, first col.].
In regard to claim 2, Walker teaches the multiple metallic medium and trace element sources comprise calcium source, magnesium source, boron source, molybdenum source, iron source, zinc source, manganese source and copper source (e.g. NPKS in addition to micronutrients including zinc, copper, iron, manganese, boron, molybdenum and secondary nutrients calcium, magnesium and silicon [pg. 19, last para.].
In regard to claim 3, Walker teaches wherein the controlled release fertilizer contains components [pgs. 17-19; 21]:
ppw
Calculated as wt.%
w/w %
ammonium polyphosphate
100-300
7-32
phosphorous
0.5-15
nitrogen source
400-700
29-68
nitrogen
1-15
potassium source
150-450
11-44
potassium
0.5-12
calcium source
10-50
0.6-6.5
secondary nutrient
0.5-18
magnesium source
50-100
3-13
0.5-18
boron source
1-3
0.06-0.41
trace nutrient
0.01-2
molybdenum source
1-3
0.06-0.41
0.01-2
iron source
5-20
0.3-2.7
0.01-2
zinc source
0.5-1
0.03-0.14
0.01-2
manganese source
1.5-2
0.09-0.28
0.01-2
copper source
0.5-1
0.03-0.14
0.01-2
agglomerant
5-30
0.31-4
binder
1-10
The ranges calculated from the Walker reference overlap or lie inside the claimed ranges. With regard to the ranges of the nitrogen source claimed, because Walker recites the percentage of total nitrogen, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that to achieve a total nitrogen content within the ranges disclosed by Walker would necessarily require a greater amount of “nitrogen source” as claimed (e.g. if urea is the nitrogen source, a nitrogen content would be between 13-31% which overlaps with the Walker range).
In regard to claim 4, Walker teaches wherein the nitrogen source is ammonium nitrate phosphate (e.g. ammonium nitrate and monoammonium phosphate) [pg. 18], and the potassium source is potassium sulfate [pg. 19].
Claims 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Walker (WO-2022133548) in view of Whittington (US Patent Publication No. 2005/0076687) and Wang et al. (ACS omega, 2021) as applied to claim 4 above, and further in view of Kopf et al. (US Patent Publication No. 2022/0332659).
In regard to claims 5-8, Walker discloses NPKS in addition to micronutrients including zinc, copper, iron, manganese, boron, molybdenum and secondary nutrients calcium, magnesium and silicon [pg. 19, last para.] but does not explicitly disclose the suitable salts as claimed.
Kopf et al. is directed to fertilizer granules based on inorganic salts [abstract]. The fertilizers described by Kopf may contain macronutrients [0092] and micronutrients [0096].
In regard to claim 5, Kopf teaches a calcium source as potassium calcium magnesium sulfate (e.g. polyhalite K2Ca2Mg(SO4)4.2H2O) [0095] and a magnesium source selected from a group consisting of magnesium sulfate, magnesium nitrate and magnesium chloride (e.g. suitable salts include magnesium sulfate, magnesium chloride) [0095].
In regard to claim 6, Kopf teaches a boron source (e.g. sodium borate or boric acid) [0096] and a molybdenum source (e.g. sodium molybdate or ammonium molybdate) [0096].
In regard to claim 7, Kopf teaches an iron source (e.g. iron EDTA chelates) and a zinc source (e.g. zinc sulfate) [0096].
In regard to claim 8, Kopf teaches a manganese source (e.g. manganese sulfate) and copper source (e.g. copper sulfate) [0096].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the macronutrient and micronutrient components recited by Kopf. One of ordinary skill in the art would have been motivated to choose from well-known and predictable materials frequently used in the art when the general conditions of the claimed nutrient elements are disclosed.
Response to Arguments
Applicant’s amendments (04/16/2026) to the claims overcome the rejection(s) based on 35 U.S.C. 112(b) as set forth in the prior Office Action.
Applicant argues (pg. 7, last 2 para.) the prior art does not envision whether the phosphorus and trace elements within the coating can be released from the polyurethane coating. In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., fertilizer envelopes comprising phosphorus or trace elements) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Applicant argues (pg. 8, 1st para.) one of skill in the art would not have had motivation to coat the core granules of Zhang with a film in the absence of any prior art disclosing a controlled-release fertilizer with the core granule composition of the present invention. In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). In the case of Zhang the reference teaches fertilizer envelopes include oil or powder (e.g. fertilizer granules are coated with powder and oil) [0018] but does not explicitly recite polyurethane envelopes with Wynnyk et al. describing that it is known in the art to coat particulate plant nutrient with oil to improve the release profiles of the plant nutrient [0007] and that polyurethane used to produce a coating that is less susceptible to damage during the mechanical handing of the fertilizer material [0020]. Polyurethane coatings on fertilizer granules are known in the prior art for controlled-release fertilizers.
Applicant argues (pg. 8, para. 2 – pg. 9, para. 2) a person skilled in the art could not conceive of a fertilizer coating “simultaneously ensuring and improving the utilization rate of phosphorus and trace elements in the phosphate fertilizer". In response to applicant's argument that the claimed fertilizer improves utilization rates of phosphorus and trace elements, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Wynnyk teaches it is known to use coatings such as polyurethane coatings to control the release rate of the nutrients in the fertilizer to the surrounding soil at a specified rate [0010]. Applicant’s describe the polyurethane coating as overcoming the issues related to orthophosphate and metal trace elements precipitation: “[…] orthophosphate and metal trace elements are prone to precipitation. After forming the polyurethane coating, both ammonium polyphosphate and the medium and trace elements in the fertilizer core particles are able to be slowly released from the polyurethane coating.” [Specification pg. 8, lines 15-20]. Thus, the presence of a polyurethane coating as made obvious by Wynnyk would achieve the same result obtained by Applicants.
Therefore, Applicant's arguments filed 04/16/2026 have been fully considered but they are not persuasive.
Conclusion
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 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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/JENNIFER A SMITH/Primary Patent Examiner, Art Unit 1731 April 27, 2026
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