DETAILED ACTION
Claim Objections
Claims 1-16 are objected to because of the following informalities: Claims 1 and 7 are drawn to a bicyclic hafnium metallocene having non-identical ligands and a catalyst composition comprising a bicyclic hafnium metallocene having non-identical ligands. Groups X attached to the metal center are also considered ligands. The specification was consulted for guidance. Exemplary compounds n-PrCp(1,3-dimethyl-4,5,6-tetrahydropentalenyl)hafnium dichloride and n-PrCp(1,3-dimethyl-3,,5,6-tetrahydropentalenyl)hafnium dimethyl contain identical chloride and identical methyl groups, respectively. Based on these observations, claims do not appear to describe Applicant’s invention accurately. Dependent claims are subsumed under the rejection.
Claim 9 is objected to because of the following informalities: In line 3, delete “be”.
Claim 11 is objected to because of the following informalities: In line 2, please replace “the bicyclic” with “a bicyclic”.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
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 1-3, 7-11, and 13-16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Holtcamp et al. (US 2019/0168203).
Holtcamp et al. discloses a catalyst system containing an activator, a support, and the hafnocene compound shown below, corresponding to claimed compound of structure (I) in which n = 2 (claims 1, 9, 21, and 22). The activator to metallocene molar ratio is 1:1 to 500:1 (paragraph [0097]). The catalyst may be spray dried (paragraph [0106]). The catalyst is used in a process for making a polyolefin composition (claim 23). Polymerization is carried out in a gas phase reactor (paragraph [0194]).
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Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Holtcamp et al. (US 2019/0168203).
The discussion of the disclosure of the prior art from the preceding paragraph is incorporated here by reference. Reference is silent with regard a molecular weight comonomer distribution index of resulting polymers. However, one of ordinary skill in the art would have expected a polymer prepared using substantially the same catalyst containing claimed hafnocene compound in claimed gas phase polymerization process to exhibit substantially the same molecular weight property. Since the PTO cannot perform experiments, the burden is shifted to the Applicants to establish an unobviousness difference. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112-2112.02.
Claims 1-4, 7-9, 11, 13, 15, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over McCullough (US 6,911,508).
McCullough discloses a metallocene compound represented by the formula shown below, wherein M is a group 4 atom. Exemplary compounds include: (1-methyltetrahydroindenyl) (cyclopentadienyl)zirconium dichloride, (2-methyltetrahydroindenyl) (cyclopentadienyl) zirconium dichloride, (1,2,3-trimethyl-tetrahydroindenyl)(cyclopentadienyl)zirconium dichloride, (2-propyltetrahydroindenyl)(cyclopentadienyl)zirconium dichloride, and (1,3-dimethyl-tetrahydroindenyl)(cyclopentadienyl)zirconium dichloride.
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A supported catalyst for gas phase polymerization of olefins is prepared by combining the metallocene compound with an activator in a ratio of about 120/1. One of ordinary skill in the art would have found it obvious to carry out the invention of prior art using correpsonding hafnium based metallocene compounds as these lie within the scope of protection of patent claims.
Claims 1-5, 7-9, 11, 13, 15, and 16 are rejected under 35 U.S.C. 103 as being anticipated by Hong et al. (EP 2679594)
Hong et al. teaches metallocene compounds represented by the formula (4Hind)(Cpʹ)MX2 wherein 4Hind is a tetrahydroindenyl group and Cpʹ is a cyclopentadienyl group including cyclopentadienyl, indenyl, and fluorenyl. Representative compounds include hafnocenes containing an alkyl-substituted 4Hind/Ind ligand pair: (1-methyl-4, 5, 6, 7-tetrahydroindenyl)(indenyl)hafnium dichloride (page 3, line 56), (2-methyl-4, 5, 6, 7-tetrahydroindenyl)(indenyl)hafnium dichloride (page 4, line 11), and hafnocenes containing a 4Hind/Cp ligand pair: (4, 5, 6, 7-tetrahydroindenyl)(cyclopentadienyl)hafnium dichloride (page 10, line 9), and (4, 5, 6, 7-tetrahydroindenyl)(1-methyl-3-n-butylcyclopentadienyl)hafnium dichloride (page 10, line 50). While reference does not list specifically a series of hafnium compounds containing an alkyl-substituted 4Hind/Cp ligand pair, one of ordinary skill in the art would have found it obvious from representative compounds to mix ligand sets and make compounds such as (1-methyl-4, 5, 6, 7-tetrahydroindenyl)(cyclopentadienyl)hafnium dichloride and (1-methyl-4, 5, 6, 7-tetrahydroindenyl)(1-methyl-3-n-butylcyclopentadienyl)hafnium dichloride, since these are within the scope of compounds represented by general formula (4Hind)(Cpʹ)MX2. Metallocenes of the prior art are combined with a cocatalyst in a ratio on order of 1:1000 to prepare an active catalyst for polymerization of olefins (paragraph [0025]). Additionally, the catalyst may be supported on a porous inorganic carrier (paragraph [0028]). Such a catalyst is used in a gas phase polymerization process (paragraph [0033]).
Claim 6 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. None of cited references teaches the compound depicted in claim.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to Rip A. Lee whose telephone number is (571)272-1104. The examiner can be reached on Monday through Friday from 9:00 AM - 5:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Robert Jones, can be reached at (571)270-7733. The fax phone number for the organization where this application or proceeding is assigned is (571)273-8300.
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/RIP A LEE/Primary Examiner, Art Unit 1762 March 11, 2026