DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after 16 March 2013, is being examined under the first inventor to file provisions of the AIA . In the event the determination of the status of the application as subject to AIA 35 U.S.C. §§ 102 and 103 (or as subject to pre-AIA 35 U.S.C. §§ 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Abstract Objections
The abstract filed 11 March 2026 is objected to because of the following informalities:
Applicant is reminded of the proper language and format for an abstract of the disclosure. The abstract should be in narrative form and generally limited to a single paragraph on a separate sheet within the range of 50 to 150 words in length (about 5 to 15 lines of text). The abstract should describe the disclosure sufficiently to assist readers in deciding whether there is a need for consulting the full patent text for details. Appropriate correction is required.
Response to Remarks
The remarks filed 11 March 2026 have been fully considered.
The applicant argues with regards to the rejection of claim 16 under 35 U.S.C. § 103 that:
“A. Eskew and Hruschka Do Not Teach the Claimed Hard, Non-Metal Contact Architecture and, if anything, underscore the sensitivity of plant-rubber recovery to comminution conditions.”
Upon further consideration of Eskew, the argument is not found to be persuasive. Eskew discloses using a “pebble mill”, which is known in the art to be a ball mill that has been lined with a ceramic material and may use rocks, metal, or alumina as milling media (see the attached non-patent literature of Surplus Record, section titled “The Pebble Mill”.
The applicant then argues that:
“B. Carnahan’s ‘purity’ pathway is about using resilient rubber interfaces, not hard non-metallics like ceramic, porcelain or glass-providing, at minimum, a contrary direction to the Office Action’s proposed modification.”
There can be no criticality for the narrower Markush group of “ceramic, porcelain or glass” since the broader group of “ceramic, glass, minerals, porcelain and/or polymeric materials” (see former claim 21) was, and thus still is, perfectly acceptable. Nevertheless, the examiner is no longer relying on Carnahan to teach the claimed surfaces, but reserves the right to in the future, if deemed necessary.
Further, the applicant argues that:
“C. Sun and Ogata are, at minimum, not reasonably pertinent to the problem addressed by the present disclosure, and the Office Action’s reliance on them reflects hindsight selection.”
Ogata is no longer being relied upon, but the examiner reserves the right to in the future, at which point the examiner will address the arguments directed to Ogata in detail. Like the applicant, Sun has recognized that the ball milling of materials in the conventional metal-containing milling environments contaminates the product with metal and, thus, the applicant and Sun share the same objective or field of endeavor of mitigating metal contaminants in a product produced by a ball milling process. Both also share the same solution of providing the ball chamber and milling media with surfaces consisting of corundum. Sun is analogous prior art for at least these reasons.
It should be noted that the problem of metal contaminants will persist regardless of how hard or soft the material being milled is and regardless of whether a wet milling process or dry milling process is used. For example, even in wet milling processes of the softest materials, metal contaminants will exist due to the abrasive action of the milling media (e.g., metal balls) against the metal surface of the ball chamber in ball mills constructed strictly of metal and using metal milling media. Such is inherent to these types of mills, as evidenced by the attached non-patent literature of Neumann Machinery (see the first paragraph).
Lastly, under section ‘C’ of the remarks, the applicant argues that:
The Office Action’s rationale effectively requires the skilled person to (i) recognize the specific polymer-integrity/aging issue in wet plant-rubber recovery, then (ii) search outside the plant-rubber recovery art for industrial dry-grinding equipment and generalized pulverizer hardware materials, and then (iii) select hard ceramic contact surfaces (ceramic/porcelain/glass) and apply them as both the lining and the milling media surface in a wet plant-rubber recovery method-with a reasonable expectation that this will improve polymer integrity/aging behavior rather than worsen it. That chain of reasoning is not grounded in the cited references themselves, and instead appears to depend on knowledge of Applicant's disclosure as a roadmap to select and assemble features from disparate contexts.”
The applicant’s invention is not limited exclusively to wet plant-rubber recovery, as it is classified in the general tumbling mill arts. And searching outside of the general tumbling mill arts was not required of the examiner and, thus, is not required of the skilled person. Both the applicant’s invention and the invention of Sun are classified in the general tumbling mill areas of CPC. And selecting hard ceramic contact surfaces (ceramic) and applying them as both the lining and the milling media surface in a wet plant-rubber recovery method is an obvious inference from Eskew’s disclosure of a “pebble mill”. See the response to the argument from section ‘A’ of the remarks, above.
In response to the 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). Given the cited prior art references, no further knowledge from the applicant’s disclosure is needed to make proper rejections of the claims. See the current rejections below.
Claim Objections
Claims 26-27 and 34 are objected to because of the following informalities.
In re claim 26: “after separating” should be –after the separation of– since it is referring to the step of separating in claim 16.
In re claim 27: “milling” should be –the milling of– since it is referring to the step of milling in claim 16.
In re claim 34: “boiling” should be –boiling of the– since it is referring to the step of boiling in claim 16.
Claim Rejections - 35 U.S.C. § 103
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.
Claims 16, 19-20, 22-23 and 25-29 are rejected under 35 U.S.C. § 103 as being unpatentable over Eskew et al. (US 2,393,035).
In re claim 16: Eskew discloses a method for obtaining natural rubber from plant material (pg. 1, col. 1, ln. 8-23), the method comprising:
leaching plant material of a rubber containing plant in boiling water (pg. 2, col. 1, ln. 38-39);
transferring the boiled plant material into a chamber of a pebble mill (pg. 2, col. 1, ln. 40-45; and it would be well known to an ordinary artisan that pebble mills are ball mills that have been lined with alumina or ceramic lining and are known to use alumina pebbles, as evidenced by the attached non-patent literature of Surplus Record in the section titled “The Pebble Mill”; note that alumina pebbles are known to be spherical/ball shaped);
milling the plant material using milling media in the ball chamber to form natural rubber flakes (pg. 2, col. 1, ln. 2-14, 27-35; note that the specification at pg. 5, ln. 20-22 defines the “flakes” as being 0.5 to 5 cm diameter and, thus, the agglomerated masses of Eskew read on the claimed flakes);
separating the natural rubber flakes from the milling media (pg. 2, col. 1, ln. 46-49); and
drying the natural rubber flakes to obtain natural rubber (pg. 2, col. 1, ln. 7-14).
Eskew does not explicitly disclose a lining of the ball chamber and the milling media each has a non-metallic surface consisting of ceramic, porcelain, or glass.
However, based on the evidence from Surplus Record, discussed above, that pebble mills are ball mills that have been lined with alumina or another ceramic, it is an obvious inference from Eskew’s disclosure of “pebble mill” that a surface of the lining of the ball chamber is alumina or another ceramic, and based on the evidence from Surplus Record that the milling media can be made of alumina, it would have been obvious to an ordinary artisan before the effective filing date of the claimed invention to select alumina as the lining and the milling media, since it has been held that selecting a material allowing for sufficient milling functionality from a list of known materials would be obvious to the ordinary artisan (MPEP § 2144.07).
In re claim 19, which depends on claim 16: Eskew discloses the non-metallic surface of the lining and the non-metallic surface of the milling media are free of heavy metals and transition metals (due to the selection of alumina as the lining and the milling media in claim 16 above, it is obvious the surface of the lining and milling media would be free of heavy metals and transition metals).
In re claim 20, which depends on claim 16: Eskew discloses the non-metallic surface of the lining and the non-metallic surface of the milling media are free of iron (due to the selection of alumina as the lining and the milling media in claim 16 above, it is obvious the surface of the lining and milling media would be free of iron).
In re claim 22, which depends on claim 16: Eskew discloses teaches the non-metallic surface of the lining and the non-metallic surface of the milling media consists of aluminum oxide ceramic (alumina is synthetic aluminum oxide).
In re claim 23, which depends on claim 16: Eskew discloses the non-metallic surface of the lining and the non-metallic surface of the milling media consist of the same material (due to the selection of alumina as the lining and the milling media in claim 16 above).
In re claim 25, which depends on claim 16: Eskew discloses the plant material is milled in the ball mill in the presence of water (pg. 2, col. 1, ln. 40-45, 50-56).
In re claim 26, which depends on claim 16: Eskew discloses washing the plant material after separating the natural rubber flakes from the milling media (pg. 2, col. 2, ln. 4-5).
In re claim 27, which depends on claim 16 and is being examined as best understood: Eskew discloses subjecting the plant material to pre-comminution prior to the milling of the plant material (pg. 1, col. 2, ln. 37-41 and pg. 2, col. 1, ln. 2-6).
In re claim 28, which depends on claim 16: Eskew discloses the plant material originates from the plant genus dandelion (pg. 2, col. 2, ln. 38-39).
In re claim 29, which depends on claim 16: Eskew discloses the plant material originates from the plant species Russian dandelion (pg. 2, col. 2, ln. 38-39).
Claim 24 is rejected under 35 U.S.C. § 103 as being unpatentable over Eskew, in view of Carnahan (US 1,807,383).
In re claim 24, which depends on claim 16: modified Eskew does not explicitly teach the ball mill is a drum mill or tube mill.
However, Carnahan further teaches the mill 1 (fig. 1) is a drum mill or tube mill (pg. 3, ln. 118-124). Therefore, it would have been obvious to the ordinary artisan before the effective filing date of the claimed invention to further modify Eskew such that the ball mill is a drum mill or tube mill, as taught by Carnahan, because selecting from known types of mills allowing for sufficient milling functionality of plant material would be obvious to the ordinary artisan.
Claim 30 is rejected under 35 U.S.C. § 103 as being unpatentable over Eskew, in view of Hruschka et al. (US 2019/0233595).
In re claim 30, which depends on claim 16: modified Eskew does not teach the plant material comprises the roots and the hypocotyl.
However, Hruschka teaches the plant material comprises the roots and the hypocotyl (¶ 14). Therefore, it would have been obvious to an ordinary artisan before the effective filing date of the claimed invention to further modify Eskew such that the plant material comprises the roots and the hypocotyl, as taught by Hruschka, because applying known techniques to yield predictable results requires only routine skill in the art (KSR Int’l Co. v. Teleflex Inc., 127 S.Ct. 1727, 1742, 82 USPQ2d 1385, 1396 (2007)).
Claim 33 is rejected under 35 U.S.C. § 103 as being unpatentable over Eskew, in view of Sun (CN 111 135 912 A).
In re claim 33, which depends on claim 16: modified Eskew does not explicitly teach the non-metallic surface of the lining and the non-metallic surface of the milling media each consist of corundum and are free of heavy metals and transition metals including iron.
However, alumina was selected as the material for the lining and milling media in claim 16 above. Note that alumina is the synthetic form of aluminum oxide, while corundum is the crystalline form; both alumina and corundum are considered ceramic materials.
Sun teaches ball milling materials in a ball chamber wherein lining plates of the chamber are made of corundum and the milling media to be used in the mill is also made of corundum, which is a non-metallic material selected to avoid excessive heavy metal content in the ground product (§§ [0014], [0036]). Like the applicant, Sun has recognized that the ball milling of materials in the conventional metal-containing milling environments contaminates the product with metal and, thus, Sun is pertinent to the applicant’s objective. Therefore, it would have been obvious to the ordinary artisan before the effective filing date of the claimed invention to further modify Eskew such that a lining of the ball chamber and the milling media each has a non-metallic surface consisting of corundum, since it has been held that selecting a material allowing for sufficient milling functionality from a list of known materials would be obvious to the ordinary artisan (MPEP § 2144.07).
Claim 34 is rejected under 35 U.S.C. § 103 as being unpatentable over Eskew, in view of Querci et al. (US 2018/0371112).
In re claim 34, which depends on claim 16: Eskew discloses boiling the plant material in water (pg. 2, col. 1, ln. 38-39).
Eskew does not explicitly disclose the boiling is for 20 to 60 minutes. However, Eskew discloses the purpose of boiling the plant material is to remove the carbohydrates within it (pg. 2, col. 2, ln. 38-39). Thus, an ordinary artisan would understand that boiling time is a result-effective variable as an amount of carbohydrates removed would depend on the duration of boiling time.
And Querci teaches leaching rubber-containing plant material at a temperature between 25°C and the boiling point of the solvent being used for 0.1 to 5 hours (¶ 91). Therefore, it would have been obvious to the ordinary artisan before the effective filing date of the claimed invention to modify Eskew such that the plant material is boiled for 20 to 60 minutes, since it has been held that where the general conditions of the claim are met in the prior art, determining the optimum or workable ranges requires only routine skill in the art (MPEP § 2144.05).
Allowable Subject Matter
Claim 32 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
None of the cited prior art references teach natural rubber flakes having an iron content of 0.05 percent, at least when combined with the other limitations of claims 16 and 32. As modified in claim 16 above, Eskew teaches the non-metallic surface of the lining and the non-metallic surface of the milling media each consist of corundum and, as such, one would not expect to find any iron in the milled product of modified Eskew. Further, it would not be obvious to further modify Eskew to meet this limitation.
Conclusion
Applicant’s amendment necessitated any new ground(s) of rejection presented in this Office Action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jared O. Brown whose telephone number is 303-297-4445. The examiner can normally be reached on Monday - Friday: 8:00 - 5:00 (Mountain Time).
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/JARED O BROWN/Primary Examiner, Art Unit 3725