DETAILED ACTION
This Office Action is responsive to the amendment filed on 10/6/2025.
The objections and rejections not addressed below are deemed withdrawn.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
The present application, filed on or after March 16, 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 (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.
Claim Rejections - 35 USC § 103
Claim(s) 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over Piel et al, EP2583998 (of record).
Piel discloses a polyethylene composition (for claims 1, 18) used in the production of pipes and/or fittings (for claims 11, 12, 14) (abstract), wherein said composition comprises base resin comprising a low molecular weight (LMW) fraction (A) and high molecular weight (HMW) fraction (B). Said composition is characterized by a MFR5 of 0.6 g/10 min or less (¶0010, 0022), overlapping the claimed range (for claims 1, 18) and an olefin comonomer content in the range of 0.1 to 3.0 mol% (¶0024), overlapping the claimed range (for claims 3, 16). Said base resin has a number average molecular weight (Mn) in the range of 8000 to 15000 (¶0032), overlapping the claimed range (for claims 6, 17), and is made via multistage polymerization (¶0033) using a Ziegler Natta catalyst for claim 5) (¶0050). The prior art composition has a critical temperature of -10 °C or lower (¶0014), overlapping the claimed range (for claim 13). Said comonomer is especially preferred to be 1-butene or 1-hexene (for claims 1, 18) (¶0021).
Regarding claimed component (A): The prior art LMW fraction (A) is characterized by a MFR2 not more than 100 g/10 min, overlapping the claimed range (for claims 1, 4, 8, 10, 18), and is preferably an ethylene homopolymer (for claim 4) (¶0010, 0020). Piel further discloses that fraction (A) has a lower molecular weight than fraction (B) (¶0010); the prior art fraction (A) therefore corresponds to claimed component (A) (for claims 1, 8, 18).
Regarding claimed component (B): The prior art HMW fraction (B) is preferably a copolymer of ethylene and 1-butene and/or 1-hexene (for claim 3) (¶0021).
"[I]n considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom." In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 1968) (MPEP § 2144.01). Piel teaches that 1) the overall prior art composition comprises 0.1 to 3.0 mol% olefin comonomer (¶0024) and 2) that the composition preferably comprises a homopolymer LMW fraction and copolymer HMW fraction, specifically teaching that the HMW fraction is the only fraction to contain olefin comonomer (¶0030). As 1-butene and 1-hexene are especially preferred embodiments of the olefin comonomer present in the HMW fraction (B) (¶0021); Piel renders obvious a composition wherein LMW fraction (A) comprises 100% ethylene and HMW fraction (B) is either an ethylene/1-butene copolymer or an ethylene/1-hexene copolymer.
The prior art composition comprises 0.1 to 3.0 mol% of the olefin comonomer. When 1-butene is the comonomer, the prior art composition comprises 0.1 to 3.0 mol% 1-butene and (deduced) 97.0 to 99.9 mol% ethylene. Based on the molecular weights of 1-butene (56.1 g/mol) and ethylene (28.05 g/mol), it is calculated that this corresponds to a 1-butene content of about 0.2 to 5.82 wt% relative to the overall composition. As noted above, Piel specifically envisions a composition wherein the comonomer is only present in HMW fraction (B), which is present in an amount of 45 to 65 wt% of the composition (¶0031). Based on the 1-butene content relative to the overall composition and the amount of HMW fraction, it is estimated that the prior art HMW fraction (B) may contain about 0.3 to 12.9 wt% butene (i.e., about 0.1 to 6.9 mol%), overlapping the claimed range (for claims 1, 8, 18).
Similarly, based on the molecular weights of ethylene (58.05 g/mol) and 1-hexene (84.1608 g/mol), it is calculated that when 1-hexene is the comonomer, the 1-hexene content of the HMW fraction (B) is in the range of about 0.5 to 18.9 wt% (i.e., about 0.2 to 7.2 mol%), overlapping the claimed range (for claims 1, 8, 18). The prior art HMW fraction (B) therefore corresponds to claimed component (B) (for claims 1, 8, 18).
Regarding the ratio of component (A) to component (B): The ratio of LMW fraction (A) to HMW fraction (B) ranges from 35:65 to 55:45 (¶0031); i.e.-the prior art base resin comprises 45 to 65 wt% of the HMW fraction (B) (for claims 1, 8, 18).
Regarding claim 2: Note that the instant claim only states that the composition has a molecular weight distribution (Mw/Mn); the claim does not require that this property have a value within a specific range. Piel teaches that the prior art composition has a Mw/Mn (¶0032).
Regarding the claimed process steps: As noted above, the prior art composition is prepared via a multistage process using a Ziegler-Natta catalyst (for claims 8, 10). Piel exemplifies a process comprising the steps of 1) a prepolymerization step (for claim 9), 2) polymerizing the LMW fraction (A) in a loop reactor (for claim 8), 3) transferring the LMW fraction (A) to a gas phase reactor wherein the HMW fraction (B) is then polymerized (for claim 8), and extruding the product (for claim 8) (¶0102-0103; Table 1). The LMW fraction was prepared using an alkyl aluminum co-catalyst and hydrogen as a chain transfer agent (for claim 8) (¶0065, 0102, Table 1).
Piel does not specifically disclose the production of a composition wherein the HMW fraction has a comonomer content in the range of 0.3 to 1.0 mol% and the overall composition has a strain hardening modulus from 50 to 150 MPa.
Regarding the comonomer content: It has been held that in the case where the claimed ranges overlap or lie inside ranges disclosed in the prior art, a prima facie case of obviousness exists; see 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). The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages; see In re Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 (" (MPEP § 2144.05). The prior art range for the comonomer content of HMW fraction (B) overlaps the claimed range. Barring a showing of evidence demonstrating unexpected results, it therefore would have been obvious to prepare a composition having the required comonomer content in view of the teachings of Piel (for claim 1).
Regarding the claimed properties of strain hardening modulus (for claims 1, 7, 8, 18) and pressure resistance (for claim 15): As discussed in the previous paragraphs, Piel renders obvious a composition comprising the same polymers made from the same monomers combined in the same amounts as used to prepare the claimed invention. Furthermore, the prior art composition is prepared via a similar method of multistage polymerization using a Ziegler Natta catalyst as used to prepare the claimed invention. “[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his [or her] claimed product. Whether the rejection is based on inherency under 35 U.S.C. 102, on prima facie obviousness under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same…" as that required with respect to product-by-process claims. In re Fitzgerald, 619 F.2d 67, 70, 205 USPQ 594, 596 (CCPA 1980) (MPEP § 2112). As the prior art composition appears to be the same as the claimed composition, it is reasonably expected that its properties would not be materially different from those of the claimed composition. The burden is therefore shifted to the applicant to provide evidence of an unobvious difference between the claimed invention and the prior art composition (for claims 1, 7, 8, 15, 18).
Response to Arguments
Applicant's arguments filed 10/6/2025 have been fully considered but they are not persuasive.
Applicant argues that Piel doe not disclose a composition wherein the HMW fraction has a comonomer content in the range of 0.3 to 1.0 mol% and the composition has a strain hardening modulus from 50 to 150 MPa. Applicant further alleges that the previous Office Action does not address Piel’s lack of disclosure of the strain hardening modulus.
With regards to the comonomer content of the HMW fraction: Piel discloses that the HMW fraction is an ethylene/olefin copolymer, wherein the olefin comonomer is especially preferred to be either 1-butene or 1-hexene (¶0021). Furthermore, as discussed in both paragraphs 15 to 17 of the Office Action mailed on 7/8/2025 and paragraphs 10 to 12 of this Action, one of ordinary skill in the art can calculate that the comonomer content of the HMW fraction is in the range of about 0.1 to 6.9 mol% when the comonomer is 1-butene and about 0.2 to 7.2 mol% when the comonomer is 1-hexene. Note that both of these ranges overlap the claimed range for the comonomer content of ethylene copolymer (B). The prior art range for the comonomer content of the HMW fraction and the claimed range overlap. Barring a showing of evidence demonstrating unexpected results, Piel therefore renders obvious a composition wherein the HMW fraction has a comonomer content within the required range; see In re Wertheim, In re Woodruff, and In re Peterson cited earlier in this Action.
Regarding the strain hardening modulus: Contrary to applicant’s argument, the previous Office Action did not fail to address the claimed strain hardening modulus. As discussed in paragraph 23 of the 7/8/2025 Office Action and paragraph 18 of this Action, it has been held that “[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his [or her] claimed product. Whether the rejection is based on inherency under 35 U.S.C. 102, on prima facie obviousness under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same…" as that required with respect to product-by-process claims; see In re Fitzgerald (MPEP § 2112(V)). As noted above, the Piel renders obvious a composition wherein
the prior art composition has the same MFR5, olefin comonomer content, Mn, and critical temperature as the claimed invention;
the prior art composition comprises a LMW fraction and a HMW fraction which correspond to claimed (co)polymers (A) and (B), respectively;
the ratio of LMW: HMW fraction in the prior art composition is within the claimed range;
the prior art composition is made via a similar method of multistage polymerization using a Ziegler Natta catalyst as the claimed invention; and
the prior art composition is used for the same purpose as the claimed invention.
The composition rendered obvious by Piel therefore appears to be the same as the claimed composition. It is therefore reasonably expected that it would have the same strain hardening modulus as the claimed composition; see In re Fitzgerald cited above. The burden is therefore properly shifted to applicant to provide evidence demonstrating an unobvious difference between the claimed invention and the prior art composition.
Applicant argues that the claimed invention yields unexpected results, citing the examples from the instant specification.
A demonstration of unexpected results must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness; see In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979). Where the comparison is not identical with the reference disclosure, deviations therefrom should be explained, In re Finley, 174 F.2d 130, 81 USPQ 383 (CCPA 1949), and if not explained should be noted and evaluated, and if significant, explanation should be required. In re Armstrong, 280 F.2d 132, 126 USPQ 281 (CCPA 1960) (MPEP 716.02(e).
As noted earlier in this Action, the LMW fraction of Piel has a MFR2 not more than 100 g/10 min; in contrast, applicant’s specification discloses that the compositions of CE2 to CE7 all have MFR2 values outside this range (see specification Table 2). Furthermore, the overall composition of Piel has a minimum comonomer content of 0.1 mol%, whereas applicant’s CE1 has an overall comonomer content of 0.06 mol% (specification Table 3). None of the comparative examples therefore fall within the scope of the Piel. Applicant does not address the differences between the comparative examples and Piel; the evidence currently in the record therefore does not establish that applicant has compared the claimed invention to the closest prior art as required.
Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range; see In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). The nonobviousness of a broader claimed range can be supported by evidence based on unexpected results from testing a narrower range if one of ordinary skill in the art would be able to determine a trend in the exemplified data which would allow the artisan to reasonably extend the probative value thereof; see In re Kollman, 595 F.2d 48, 201 USPQ 193 (CCPA 1979) (MPEP § 716.02(d)).
The cited examples are not commensurate in scope with the invention as claimed. With regards to claim 1, it is first noted that the claimed invention states that the comonomer may be either 1-butene or 1-hexene; however, all of the provided examples use 1-hexene as the comonomer. No examples have been provided wherein 1-butene is the comonomer. As such, there is no evidence in the record that the allegedly unexpected results may be obtained from a composition comprising 1-butene as a comonomer. The allegedly unexpected results therefore are not commensurate in scope with the claimed invention.
To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960) (MPEP § 716.02(d)(II)). As written, the claimed invention is a composition wherein the copolymer (B) may have a comonomer content in the range of 0.30 to 1.00 mol%. Note, however, that the provided examples only disclose compositions wherein the comonomer content of copolymer (B) is in the range of 0.47 to 0.69 mol% (see specification Table 3). These data points are all limited to the middle portion of the claimed range; no data has been provided to demonstrate that the allegedly unexpected results are obtained when the comonomer content of copolymer (B) is in the lower and upper portions of the claimed range. Similarly, the provided examples are not commensurate in scope with the broad ranges for MFR2, MFR5, and amount of copolymer (B) used to define the claimed composition. The cited data therefore is not commensurate in scope with the claimed composition.
Furthermore, note that the comonomer contents of the comparative examples (see CE3: 0.26 mol% and CE2: 1.16 mol%) are much closer to the claimed lower and upper limits of 0.30 and 1.00 mol% for the comonomer content of copolymer (B) than the values of the inventive examples. Because the differences between the inventive examples and the claimed upper and lower limits is so much greater than the differences between the comparative examples and the claimed limits, the cited data does not show the criticality of the claimed range. Applicant’s argument that the claimed invention yields unexpected results therefore is not persuasive. The rejection is therefore maintained.
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 JEFFREY S LENIHAN whose telephone number is (571)270-5452. The examiner can normally be reached Mon.-Fri. 5:30-2:00PM.
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/JEFFREY S LENIHAN/Primary Examiner, Art Unit 1765