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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 5/18/2026 has been entered. Claims 10-19 are withdrawn from consideration as being drawn to non-elected invention, and claims 1-19 are currently pending in the application.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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.
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(s) absent any evidence to the contrary. Applicant is advised of the obligation under 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 and 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Hsu et al (US 2014/0348887 A1) in view of Leikhim et al (US 4,284,532) and Pich et al (US 2016/0168955 A1).
Regarding claim 1, Hsu et al disclose a stable aqueous composition containing a crosslinked, non-ionic amphiphilic polymer capable of forming a yield stress fluid in the presence of a surfactant (abstract). See example 33 (paragraphs 0169, 0211, and Table 8), wherein the polymer (i.e., reads on the polymer in present claim 1) is formed from monomers BEM (i.e., ethoxylated behenyl methacrylate and reads on the hydrophobic monomer in present claim 1) and AMPS (i.e., 2-acrylamido-2-methylpropane sulfonic acid and reads on the hydrophilic monomer in present claim 1).
Hsu et al are silent with respect to glycol ether; polymer prepared by RAFT micellar polymerization in the presence of glycol ether; powder composition; and properties.
However, regarding glycol ether, Hsu et al teach that yield stress fluid comprises at least one crosslinked nonionic amphiphilic polymer and an optional nonionic surfactant (paragraph 0121). Examples of nonionic surfactants are described in US Patent 4,284,532 (Leikhim et al) and incorporated herein in its entirety (paragraph 0147). Nonionic surfactants, in Leikhim et al, have the formula R(C2H4O)nOH wherein R is aliphatic hydrocarbyl radical containing from about 8 to about 18 carbon atoms, and n = about 3 to about 12 (col. 1, lines 55-68). Therefore, in light of the teachings in Leikhim et al and general disclosure of Hsu et al, it would have been obvious to one skilled in art prior to the filing of present application to include any of the nonionic surfactants including that taught in Leikhim et al, in the composition, of Hsu et al, absent evidence to the contrary.
Regarding polymer prepared by RAFT micellar polymerization in the presence of glycol ether, claims are written in a product-by-process form. Even though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” See In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985).
Regarding powder composition, Pich et al in the same field of endeavor teach powder polymer for use in hydraulic fracturing (abstract). For ease of handling, emulsions have been used for several years but have the following disadvantages such as cost practically doubled with respect to powder polymers (paragraphs 0007-0009). Therefore, in light of the teachings in Pich et al, it would have been obvious to one skilled in art prior to the filing of present application, to prepare the composition, of Hsu et al in view of Leikhim et al, in the form of a powder, for above mentioned advantages.
Regarding properties, Hsu et al teach that amphiphilic polymers can be activated by a surfactant to provide a suitable yield stress fluid with the ability to suspend particles and insoluble materials in an aqueous medium for indefinite periods of time (paragraph 0120) and include crosslinked nonionic amphiphilic polymer (paragraph 0121). The amount of amphiphilic polymer utilized in forming the yield stress fluid is about 0.5 to about 5% by weight based on weight of the total composition (paragraph 0127). Therefore, given that the polymer is crosslinked, can be present in low amounts of about 0.5 wt% in preparing the yield stress fluid, and the activation of the crosslinked amphiphilic polymer with surfactant provides a suitable fluid with the ability to suspend particles and insoluble materials in an aqueous medium for indefinite periods of time, one skilled in art prior to the filing of present application would have a reasonable basis to expect the polymer, of Hsu et al in view of Leikhim et al and Pich et al, to form a three-dimensional interconnected network of bodies after hydration at a low shear ranging from 1500 rpm to less than 3,000 rpm when polymer is used in small amounts based on the weight of total composition, absent evidence to the contrary. Since PTO cannot conduct experiments, the burden of proof is shifted to the applicants to establish an unobviousness difference, see In re Best, 562 F.2d 1252, 195 USPQ 430 (CCPA 1977).
Regarding claim 4, example of nonionic surfactant, in Leikhim et al, include those having formula R(C2H4O)nOH wherein R is aliphatic hydrocarbyl radical containing from about 8 to about 18 carbon atoms, and n = about 3 to about 12 (col. 1, lines 55-68).
Regarding claims 5 and 6, example of nonionic surfactant, in Leikhim et al, include those having formula R(C2H4O)nOH wherein R is aliphatic hydrocarbyl radical containing from about 8 to about 18 carbon atoms, and n = about 3 to about 12 (col. 1, lines 55-68). When R is aliphatic hydrocarbyl radical containing about 8 carbon atoms and n = about 3, it reads on diethylene glycol octyl ether in present claim 5. Additionally, it is the Office’s position that when R is an aliphatic radical having about 8 carbon atoms, it is a homolog of diethylene glycol hexyl ether. Case law holds that structural similarities have been found to support a prima facie case of obviousness. See, In re Wilder, 563 F.2d 457, 460, 195 USPQ 426, 429 (CCPA 1977) (adjacent homologs and structural isomers).
Regarding claim 7, Hsu et al teach that surfactants are present in amounts of about 6 to about 20% by weight (paragraph 0152). Leikhim et al teach that ethoxylated nonionic surfactant are present in amounts of about 5 to about 25% (col. 1, lines 55-59).
Regarding claims 8 and 9, examples of suitable anionic surfactants, in Hsu et al, include sodium salts of laureth sulfate (paragraph 0131) which reads on a salt containing alkyl sulfate anion in present claim 8 and sodium lauryl sulfate in present claim 9.
Claims 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Hsu et al (US 2014/0348887 A1) in view of Leikhim et al (US 4,284,532), Pich et al (US 2016/0168955 A1) and Hanson et al (US 2018/0251583 A1).
The discussion with respect to Hsu et al, Leikhim et al, and Pich et al in paragraph 8 above is incorporated here by reference.
Hsu et al, Leikhim et al and Pich et al are silent with respect to zwitterionic monomer.
However, Hanson et al in the same field of endeavor teach film-forming compositions comprising zwitterionic-functional polymer and methods of treating subterranean formation (abstract). Exemplary ethylenically unsaturated monomers that may be used as the zwitterionic monomer include betaine-containing monomer such as sulfobetaines represented by formula:
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wherein A = O or NH; R1 is hydrogen or methyl, R2 is ethylene or propylene, R3 and R4 are alkyl typically containing from 1 to 4 carbon atoms; B is N, n = 1 to 4, and X- = SO3- (paragraph 0020). After treatment with the film-forming composition, oil permeability increased which may allow for an enhanced oil recovery in a subterranean formation (paragraph 0076). Therefore, in light of the teachings in Hanson et al, it would have been obvious to one skilled in art prior to the filing of present application to include the zwitterionic monomer, of Hanson et al, in the polymer, of Hsu et al, for above mentioned advantages.
Response to Arguments
Applicant's arguments, filed 5/18/2026, have been fully considered but they are not persuasive. Specifically, applicant argues that (A) claim 1 is directed to a powder composition comprising a polymer prepared by a RAFT micellar polymerization (namely a Reversible Addition-Fragmentation Chain Transfer micellar polymerization). The polymer that is specifically obtained by a RAFT micellar polymerization has a controlled structure which is not systematically obtained in a micellar polymerization, and which is due to the additional use of a control agent. The claimed polymeric compositions and systems are "useful for maintaining particle dispersions for extended periods of time via a three-dimensional interconnected network of bodies in the system after hydration"; (B) Candau teaches that micellar polymerization leads to heterogeneous polymers. In contrast with homogeneous copolymerization where the hydrophobes are randomly distributed along the backbone, the micellar polymerization should favor their incorporation as blocks rather than as isolated units owing to their high local concentration in the micelles. Thus, full conversion samples may contain an important proportion of homopolyacrylamide chains which increases with an increasing initial number of hydrophobes per micelle and one can anticipate that this heterogeneity will modify the formation of intermolecular associations and alter the rheological behavior; and (C) Chiefari teaches that a RAFT polymerization allows for a very specific controlled structure that is not allowed by other technologies: Living polymerization processes offer many benefits. These include the ability to control molecular weight and polydispersity and to prepare block copolymers and other polymers of complex architecture materials which are not readily synthesized using other methodologies; (D) as previously discussed, the provided evidence shows that there is an unexpected result in enhanced particle dispersion capabilities when the claimed polymeric systems for particle dispersions are used in lower amounts compared with conventional carrier systems;
With respect to (A), as stated earlier, claims are written in a product-by-process form. Case law holds that patentability of a product does not depend on its method of production. If the product in product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” See In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985). No evidence is provided to show that composition, in which glycol ether is added to the polymer after it is formed by conventional polymerization process, as in Hsu et al, would not have the three-dimensional interconnected network of bodies in the system after hydration at low shear rate as presently claimed.
With respect to (B), claims do not require the polymer to exhibit homogeneous behavior and there is nothing on record to indicate that homogeneity is required for the formation of three-dimensional interconnected network of bodies in the system after hydration. Additionally, Candau states that its hydrophobically modified polyacrylamides are prepared by micellar polymerization (title). Special emphasis is put on the improvement of the technique so that well characterized and homogeneous samples are synthesized (abstract). Hence, it is clear that micellar polymerization by itself does not result in the formation of a heterogeneous polymer. Further, Candau et al deals with polymerization of acrylamides and not acrylate monomers as in present invention.
With respect to (C), claims do not require the polymer to have a certain molecular weight and polydispersity. In fact, in present application, molecular weight is broad in the range of 5,000 to 20,000,000 (i.e., 20 million) (see paragraph 0138 of present application as filed). One skilled in art would have a reasonable basis to expect the polymer, of Hsu, to have a molecular weight falling within the range obtained by RAFT polymerization of present invention.
With respect to (D), no evidence is provided comparing it to the closet prior art of Hsu, wherein surfactants, such as glycol ethers, are added after the polymerization. Hence, any data arguing the unexpected results is not convincing.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARUNA P REDDY whose telephone number is (571)272-6566. The examiner can normally be reached 8:30 AM to 5:00 PM M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Arrie (Lanee) Reuther can be reached at 571-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/KARUNA P REDDY/
Primary Examiner, Art Unit 1764
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