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 .
Response to Amendment
The examiner acknowledges Applicant’s response filed 06/09/2026 containing remarks and claim amendments.
The rejection of claims 2 and 7-10 under 35 USC 112(b) is withdrawn in view of cancelation the same claims.
Response to Arguments
Applicant's arguments (see Remarks) have been fully considered but they are not persuasive.
35 USC § 112
On page 4, Applicant submits that claim 12 has been amended to correct a typographical error.
In response, the examiner notes that, of the two issues concerning “formula (I)” raised in the Office Action dated 02/09/2026, one issue remains unresolved. Specifically, the terminal carbon in the “-CH2-CH2-CH2” does not satisfy the neutral valence electron requirement.
35 USC § 103
On page 5, Applicant contends the Office Action does not establish a prima facie obviousness rejection “because the cited references neither teach nor suggest the claimed combination of features, nor do they provide any motivation, let alone a reasonable expectation of success, for arriving at the presently claimed methods, which yields materially distinct and unexpected improved results.” Applicant further states that MAO and MMAO differ in composition and may affect catalyst ionization, propagation, chain transfer pathways, and product distribution, such that replacing MAO with MMAO would not have been predictable.
In response, the examiner does not find the argument persuasive. Bagheri teaches the oligomerization of propylene using an unbridged metallocene/aluminoxane catalyst system to produce oligomers having a high degree of vinylidene unsaturation. Crapo teaches modified methylaluminoxane compositions suitable for use as cocatalysts with metallocene catalysts, including catalysts of the type disclosed in Bagheri, and identifies improved solubility as a benefit. In view of these teachings, one skilled in the art would have had a reason to consider the MMAO cocatalysts of Crapo as an alternative to the conventional MAO cocatalyst used in Bagheri, with a reasonable expectation of obtaining an operable a metallocene-catalyzed oligomerization process.
On pages 5-6, Applicant contends that Bagheri does not recognize or address the hydrogenated propylene oligomer content of less than about 6 wt.%. Applicant further states “Bagheri attributes terminal unsaturation to β-hydrogen elimination mechanisms in metallocene catalysis, which are fundamentally distinct from hydrogenation pathways and provide no teaching regarding suppression of hydrogenation products.”
In response, Bagheri expressly discloses that “most preferably more than about 99% of the polymer chains in the product polymer contain terminal unsaturation” (col. 9, lines 53-58). A polymer product having >99% terminal unsaturation would read on the claimed limitation of “less than about 6 wt.% of hydrogenated propylene oligomer.” Additionally, Applicant’s distinction between β-hydrogen elimination and hydrogenation does not undermine Bagheri’s express teaching concerning terminal unsaturation.
On page 6, Applicant argues that Crapo’s stated advantage of improved solubility is unrelated to the claimed high vinylidene content and reduced hydrogenated oligomer formation.
In response, the rejection does not require that the references identify the same objective as the applicant. Crapo teaches MMAO as a cocatalyst for metallocene catalysts and identifies improved hydrocarbon solubility as an advantage of the modified catalyst. Accordingly, Crapo’s improved solubility teaching provides a reason to consider MMAO as an alternative cocatalyst. The fact that Crapo does not associate improved solubility with increased vinylidene content or reduced hydrogenation does not negate the rationale for the proposed modification.
Applicant further argues that the simultaneous achievement of high vinylidene content and reduced hydrogenated oligomer content constitutes an unexpected synergistic result.
In response, Bagheri teaches producing a propylene oligomer comprising a vinylidene content of more than 80% and a terminal unsaturation of >99% (col. 4, lines 26-37; col. 9, lines 53-58), thereby reading on the claimed vinylidene content of “greater than about 70 mol%” and the hydrogenated propylene oligomer content of “less than 6 wt%.” Therefore, the contents of vinylidene and hydrogenated oligomers do not appear to be unexpected relative to the prior art.
Claim Objections
Claim 25 is objected to because of the following informalities.
Claim 25: “the propylene” should be amended to read “the propylene composition.”
Appropriate correction is required.
Claim Rejections - 35 USC § 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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 12 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 12 is indefinite for reciting “CH2=C(CH3)-(CH2-CH(CH3))n-CH2-CH2-CH2,” because the terminal carbon on the right-hand side does not meet the neutral valence electron requirement. For purposes of examination, the formula is interpreted as “CH2=C(CH3)-(CH2-CH(CH3))n-CH2-CH2-CH3” (emphasis added).
Claim Rejections - 35 USC § 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.
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.
Claims 11-18 are rejected under 35 U.S.C. 103 as being unpatentable over Bagheri et al. (US 6,043,401, cited IDS dated 01/04/2024), in view of Crapo et al. (US 5,041,584).
Regarding claim 11, Bagheri discloses a method for making a propylene oligomer comprising having a number average molecular weight Mn of about 300 to about 10,000 and a vinylidene content of more than 80%, the method comprising: contacting an unbridged metallocene complex comprising zirconium or hafnium metallocene and an aluminoxane cocatalyst with a propylene feedstock under oligomerization conditions (col. 3, lines 53-62; col. 4, lines 26-37; col. 7, line 61-col. 8, line 46). Particularly, the metallocene complex may comprise bis(cyclopentadienyl)zirconium dichloride, (H-Cp)2(Zr/Hf)Cl2 (col. 4, lines 9-13).
Bagheri does not explicitly disclose “a number average molecular weight Mn of about 200 to about 10,000.” However, the claimed range falls within the molecular weight Mn of about 300 to about 10,000 taught by Bagheri (col. 4, lines 26-37) and is, therefore, considered prima facie obvious. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05. I.
Bagheri does not explicitly disclose that the composition comprises less than about 6 wt% of hydrogenated propylene oligomer. However, Bagheri discloses that the polymer chains of the product polymer (oligomer) are essentially terminally-unsaturated and that “most preferably more than about 99% of the polymer chains in the product polymer contain terminal unsaturation” (col. 9, lines 53-58). Such a polymer product having >99% terminal unsaturation would read on the claimed limitation of “less than about 6 wt.% of hydrogenated propylene oligomer.”
While Bagheri discloses the use of methylaluminoxane, the reference does not explicitly teach a modified methylaluminoxane (a modified aluminum oxide).
However, Crapo discloses modified methylaluminoxanes containing C2 or higher alkyl groups (col. 3, line 66 – col. 4, line 21). Crapo discloses that the modified methylaluminoxanes are useful for olefin polymerization in conjunction with metallocene compounds, such as Cp2ZrCl2, and that they have higher solubility relative to conventional methylaluminoxane (col. 4, lines 42-68).
Therefore, before the effective filing date of the instant invention, it would have been obvious to one of ordinary skill in the art to modify Bagheri by substituting the conventional methylaluminoxane cocatalyst used in Bagheri with the modified methylaluminoxane cocatalyst taught by Crapo, because (i) Bagheri teaches propylene oligomerization using a metallocene catalyst and methylaluminoxane (MAO) in a solvent, such as aromatic solvents (col. 8, lines 9-17), (ii) Crapo discloses the use of modified methylaluminoxane (MMAO) with metallocene compounds, including Cp2ZrCl2, and identifies improved solubility as an advantage of the modified methylaluminoxane, and (iii) this involves application of a known aluminoxane cocatalyst alternative to improve a known process.
Regarding claim 12, the propylene oligomer with a vinylidene group (“poly(1-olefin)”), as taught by Bagheri (col. 4, lines 26-37), is considered to read on formula (I) in claim 2. While Bagheri does not explicitly teach “n = 0 to about 1000” with regard to the repeating unit “(CH2-CH(CH3))n,” the claimed invention and Bagheri teach essentially the same number average molecular weight and, therefore, it is reasonably expected that the oligomer of Bagheri has a similar number of the repeating unit as the claimed formula.
Regarding claims 13 and 14, Bagher discloses that the metallocene may comprise unsubstituted or a lower-alkyl-substituted cyclopentadienyl (col. 7, line 65 – col. 8, line 1.
Regarding claim 15, Crapo discloses that the modified methylaluminoxanes contain C2 or higher alkyl groups, where the methyl group accounts for 20-80% of the alkyl groups (col. 3, line 66 – col. 4, line 21), thereby rendering obvious the claimed formula [(CH3)(1-m)RmAIO]n, wherein 0.02<m<0.50, and R is a C3 to C15 linear or branched alkyl group.
Regarding claim 16, Bagheri discloses a vinylidene content of more than 80% (col. 4, lines 26-37).
Regarding claim 17, the claimed Mn range of “about 250 to about 10,000” falls within the Mn range of about 300 to about 10,000 taught by Bagheri and is, therefore, considered prima facie obvious (col. 4, lines 26-37),
Regarding claim 18, Bagheri discloses that the oligomer can be prepared from propylene as monomer, which suggest that the oligomer comprises 100% propylene (col. 4, lines 26-37; see Example 5).
Claims 22-24 are rejected under 35 U.S.C. 103 as being unpatentable over Bagheri et al. (US 6,043,401, cited IDS dated 01/04/2024), in view of Crapo et al. (US 5,041,584), as applied to claim 11, and further in view of Small et al. (US 8,536,391 B2, cited in IDS dated 06/24/2026).
Regarding claim 22, Bagheri, in view of Crapo (“Bagheri/Crapo”), teaches the method of claim 11, as discussed above.
Bagheri/Crapo does not teach the reaction takes place in the presence of added hydrogen.
However, Small discloses a process for metallocene-based alpha-olefin oligomerization and teaches that hydrogen may be employed during the reaction (col. 6, lines 32-60; col. 121, lines 23-32). Particularly, Small discloses that hydrogen can be used in the oligomerization process to control oligomer molecular weight and discloses conducting oligomerization at a hydrogen partial pressure ranging from 0 psig to 2000 psig (col. 121, lines 30-32 and 44-50).
Therefore, before the effective filing date of the instant invention, it would have been obvious to one of ordinary skill in the art to modify the Bagheri/Crapo process by adding hydrogen to the reaction, as taught by Small, because (i) Bagheri discloses producing an oligomer product having a specified range of average molecular range (col. 9, lines 46-51); (ii) Small teaches that hydrogen can be used to control molecular weight in metallocene-catalyzed olefin oligomerization, and (iii) one would have been motivated to employ a known hydrogen addition technique to control or adjust the molecular weight of the propylene oligomer produced by the Bagheri/Grapo process.
Regarding claim 23, Bagheri, Crapo, or Small does not teach the claimed hydrogen-to-propylene molar ratio of 0.04 or less or the claimed hydrogen partial pressure range of from 1 psig to 2000 psig. However, Small discloses a hydrogen partial pressure ranging from 0 psig to 2000 psig, such as 1 psig to 1500 psig, and teaches that hydrogen is a process variable that is used to control oligomer molecular weight (col. 121, lines 44-50). Therefore, one would have been motivated to optimize the hydrogen content in the reaction and arrive at the claimed hydrogen-to-propylene molar ratio or the hydrogen partial pressure range via routine optimization, absent evidence that the claimed ranges produce an unexpected result or critical effect. It is well established that discovering optimum or workable ranges by routine experimentation is not considered an inventive step when the general conditions of a claim are disclosed in the prior art. MPEP 21144.05 II.
Regarding claim 24, Bagheri discloses that the polymer chains of the product polymer (oligomer) are essentially terminally-unsaturated and that “most preferably more than about 99% of the polymer chains in the product polymer contain terminal unsaturation” (col. 9, lines 53-58). Therefore, it would be obvious to conclude that Bagheri teaches the claimed content of hydrogenated propylene oligomer of “less than about 5 wt.%”
Bagheri, Crapo, or Small does not teach the claimed molar hydrogen-to-propylene molar ratio of 0.01 or the propylene conversion of >90%. However, one skilled in the art would have recognized hydrogen and propylene conversion as result-effective variables, as hydrogen is used to control oligomer molecular weight while feedstock conversion directly affects product yield. Therefore, it would have been obvious for one skilled in the art to arrive at the claimed limitation, because the person of ordinary skill would have been motivated to optimize the hydrogen content in the oligomerization through routine experimentation to obtain a desired oligomer molecular weight while achieving a high degree of propylene conversion.
Claims 25-28 are rejected under 35 U.S.C. 103 as being unpatentable over Bagheri et al. (US 6,043,401, cited IDS dated 01/04/2024), in view of Crapo et al. (US 5,041,584), as applied to claim 11, and further in view of Elomari et al. (US 2012/0065447 A1).
Regarding claim 25, Bagheri, in view of Crapo (“Bagheri/Crapo”), teaches the method of claim 11, as discussed above.
Bagheri/Crapo does not explicitly disclose obtaining the propylene feedstock from a petroleum cracking operation and using the propylene feedstock without separating it from propane prior to the oligomerization.
However, Elomari a process of oligomerizing a propylene feed and teaches that propylene feedstocks may be obtained from petroleum-processing operations, including as a byproduct of steam cracking and from off-gases produced in a fluid catalytic cracking (FCC) unit ([0002], [0009]). Elomari further discloses oligomerizing a refinery propylene feed containing 77% propylene and 23% propane ([0067]).
Therefore, before the effective filing date of the instant invention, it would have been obvious to one of ordinary skill to use a propylene/propane feedstock obtained from a petroleum cracking in the Bagheri/Crapo process without separating propylene from propane, because one skilled in the art would have recognized that propylene sourced from a petroleum cracking could be used as an oligomerization feed without separating propylene from propane.
Regarding claim 26 and 27, Elomari discloses that the suitable sources of propylene include FCC, i.e., fluidized catalytic cracking ([0009]).
Regarding claim 28, Elomari discloses that the suitable sources of propylene include steam cracking ([0009]).
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jason Y Chong whose telephone number is (571)431-0694. The examiner can normally be reached Monday-Friday 9:00am-5:30pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached at (571)272-5954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JASON Y CHONG/Examiner, Art Unit 1772
/IN SUK C BULLOCK/Supervisory Patent Examiner, Art Unit 1772
