DETAILED ACTION
This is the initial Office action for application SN 18/713,754 having an effective date of 28 May 2024 and a Foreign priority date of 15 March 2022. Claims 1-18 are pending. 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(s) 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 11,148,127) in view of Hanton et al. (US 8,859,696).
Lee et al. [“Lee”] disclose a bisphosphine ligand compound having advantageous characteristics for preparation of a chromium compound and an ethylene oligomerization catalyst system including the chromium compound.
In one aspect of the invention, Lee discloses that the chromium compound can ensure remarkable improvement in activity and selectivity for ethylene oligomerization reaction to allow preparation of 1-hexene and/or 1-octene at high yield even without using methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO). COL.2, L48 to COL.3, L6.
Lee discloses that the chromium compound is represented by Formula 1 set forth in COL.3, L50-65, wherein R is a substituted or unsubstituted C1 to C60 alkyl group or C6 to C60 aryl group; the R1 s are a substituted or unsubstituted C1 to C60 alkyl group or C6 to C60 aryl group; the X s are each independently a halogen atom, a C2 to C30 carboxylate, acetylacetonate, or a C1 to C30 hydrocarbyl containing or are free from at least one selected from among an ether group and an amine group; A is boron or aluminum; and Y is a fluorine substituted C6 to C20 aryl group, a fluorine-substituted C6 to C20 aryloxy group, or a fluorine-substituted C1 to C20 alkoxy group. COL.4, L1-11.
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).
In another aspect of the invention, Lee discloses that the ethylene oligomerization catalyst system includes the chromium compound represented by Formula 1, and an organic aluminum compound represented by Formula 2 wherein R2 is a C1 to C20 alkyl group. COL.4, L18-23.
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).
In another aspect of the invention, Lee discloses that the method includes selectively preparing 1-hexene and/or 1-octene by bringing the catalyst system into contact with an ethylene monomer. COL.4, L31-34.
Applicant’s claimed method for oligomerization of ethylene comprising a step of producing an ethylene oligomer by reacting ethylene with a catalyst differs from Lee by further including a chain transfer agent [Zn(R22)2] in the catalyst system as set forth in dependent Claim 2. However, Hanton et al. [“Hanton”] is added to teach that an oligomerization process containing a chromium catalyst and a catalyst activator, the catalyst system may additionally contain a zinc compound.
Hanton discloses that the olefinic compound to be oligomerized is preferably ethylene, and that ethylene may be used to produce hexene and/or octene. COL. 19, L54 to COL.20, L2. Hanton discloses that the co-activator may be an organoaluminum compound such as trimethylaluminum. COL.18, L24-45. Hanton discloses that the zinc compound is preferably a zinc dialkyl such as dimethyl zinc or diethyl zinc. COL.19, L24-34. Hanton discloses that the zinc compound may be used as a mixed stock solution with the trialkyl aluminum, or with any other component. Hanton discloses that the use of the zinc compound in conjunction with the activator compound significantly reduces the level of solids/polymer formed as by-product during the oligomerization reaction. COL.19, L46-53.
Thus, having the prior art references before the inventor at the time the invention was made it would have been obvious to have added the zinc compound disclosed in Hanton to the catalyst system disclosed in Lee if the known imparted property was so desired. Where there is a reason to modify or combine the prior art to achieve the claimed invention, the claims may be rejected as prima facie obvious provided there is also a reasonable expectation of success. The reasonable expectation of success requirement refers to “the likelihood of success” in combining or modifying prior art disclosures to meet the limitations of the claimed invention. See Elekta Ltd. v. ZAP Surgical Sys., Inc., 81 F.4th 1368, 1375, 2023 USPQ2d 1100 (Fed. Cir. 2023) and Intelligent Bio-Sys., Inc. v. Illumina Cambridge Ltd., 821 F.3d 1359, 1367, 119 USPQ2d 1171, 1176 (Fed. Cir. 2016).
In regard to the ethylene oligomer produced by reacting ethylene with a catalyst of claims 10-18, Lee sets forth in Examples 8-16 ethylene oligomerization reactions using as the catalyst the chromium complex of Formula I and activators such iBuAl3 (tri-butyl aluminum). Lee discloses the product oligomers in Table 1 for Examples 8-16 with amounts of 1-C8 (octene) ranging from 45.1 wt.% to 67.0 wt.% and amounts of 1-C6 (hexene) ranging from 15.9 wt.% to 34.5 wt.%. Hanton also discloses Examples of oligomerization of ethylene using the catalyst system. Results are set forth in Table 1 with amounts of hexene and octene wt.% ranging from 81.6 wt.% to 87.5 wt.%.
The examiner is of the position that the claimed ethylene oligomer, produced by reacting ethylene with the catalyst of claims 10-11, does not differ from the ethylene oligomerization products set forth in either Lee or Hanton. As set forth in the MPEP, once a product appearing to be substantially identical is found and a prior art rejection is made, the burden shifts to the applicant to show a nonobvious difference. "The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature" than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
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/ELLEN M MCAVOY/ Primary Examiner, Art Unit 1771
EMcAvoy
February 6, 2026