DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
Continued Examination Under 37 CFR 1.114
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 February 19, 2026 has been entered.
Election/Restrictions
Claims 1-8, 11-14, 16, and 17 have been withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction requirement in the reply filed on July 11, 2025.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Tan et al. (US 2012/0010318) in view of Kato et al. (JPH08157613A; machine translation referred to herein) and Timken (US 2021/0332299). All references were cited in a prior Office action.
Regarding Claims 9 and 10, Tan teaches a polypropylene for a film capacitor. The polypropylene is a homopolymer having an isopentad fraction of not less than 94% a melt flow rate (MFR) of 1-10 g/10 min, and an ash content of not more than 30 ppm (Abstract). These ranges overlap or fall within the claimed ranges.
Tan does not teach the claimed content of Group 4-13 metals.
Timken teaches that single use plastic waste is an important environmental issue, and provides a method for recycling polypropylene waste to yield starting materials for polymers (p. 1, [0003], [0007]). Timken’s recycling method leads to products having a total residual content of metal contaminants of less than 10 ppm (p. 3-4, [0035]). Recycling of polypropylene-containing waste streams can produce a separate stream of propylene that may be polymerized into polypropylene products (p. 5, [0059]).
It would have been obvious to one of ordinary skill in the art at the time of filing to form Tan’s polypropylene homopolymer from Timken’s propylene containing less than 10 ppm of metal in order to take advantage of the environmental benefits associated with the use of a recycled feedstock including a reduced content of metal contaminants. A polypropylene formed from a recycled propylene stream containing less than 10 ppm of metal will necessarily contain less than 10 ppm of Group 4-13 elements (i.e. metals).
Tan’s polypropylene homopolymer is formed using a titanium catalyst on an organoaluminum carrier (p. 3, [0041]). Neither Tan nor Timken teach an appropriate content of titanium or aluminum in the polymerized product.
In the same field of endeavor, Kato teaches polypropylene having a low ash content. The polypropylene is used to form films which in turn are used to form capacitors (Abstract; p. 1, [0001]). The total ash content is preferably 30 ppm or less and the content of a group of elements including aluminum and titanium is 20 ppm or less (Abstract; p. 1, [0005], [0008]). Controlling the amount of the indicated elements including aluminum and titanium avoids reduction of insulating performance due to long-term charge increases (p. 1-2, [0009]).
It would have been obvious to one of ordinary skill in the art at the time of filing to control the amount of indicated elements including aluminum and titanium in Tan’s polypropylene homopolymer such that they are each present individually in amounts of less than 20 ppm and the sum total of all indicated elements including aluminum and titanium is less than 20 ppm according to Kato in order to avoid reduction of insulating performance due to long-term charge increases. The range of 20 ppm or less of aluminum and titanium overlaps the claimed ranges.
Modification of Tan in view of Timken and Kato results in a polypropylene homopolymer having an isopentad fraction of not less than 94%; a MFR of 1-10 g/10 min; an ash content of not more than 30 ppm; a titanium content of less than 20 ppm; an aluminum content of less than 20 ppm; and a content of all other metals (understood to include Group 4-13 metals) of less than 10 ppm. These ranges overlap the corresponding ranges in Claims 9 and 10.
An ash content of 30 ppm or less and a metal content of less than 10 ppm indicates that the amount of Groups 4-13 metals present in the ash will be less than approximately 33.3 wt%. This overlaps the claimed range of more than 0.0 up to 25.0 wt%. Thus, modification of Tan in view of Timken and Kato reads on Claims 9 and 10.
Response to Arguments
Applicant's arguments filed February 19, 2026 have been fully considered but they are not persuasive.
The Applicant argues that Kato merely discloses a total amount of metals less than 20 ppm, whereas the claims require an aluminum content of more than 0 to 1.5 ppm.
The Applicant’s attention is directed to Kato (Abstract; p. 1, [0005], [0008]) which discloses a content of a group of elements including aluminum of 20 ppm or less. It is understood that the range of 20 ppm or less (expressed by Kato as “<=20 ppm”) requires that each of the elements in the disclosed group, including aluminum, are necessarily present individually in amounts of less than 20 ppm.
The range of “less than 20 ppm” taught by Kato can also be expressed as 0-20 ppm. The claimed aluminum content of more than 0.0 ppm to 1.5 ppm falls within the range of 0-20 ppm suggested by Kato. A prima facie case of obviousness exists where the claimed ranges lie inside ranges disclosed by the prior art. See MPEP 2144.05(I).
The Applicant argues that Kato’s examples and comparative examples include metal amounts that exceed the claimed range.
Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill the art, including nonpreferred embodiments. See MPEP 2123. In this case Kato’s broader disclosure clearly suggests amounts of aluminum within the claimed range.
The Applicant argues that when reading Kato, one of ordinary skill in the art would understand that higher amounts of metals are acceptable and would therefore be encouraged to use higher metal content for ease of production.
This argument does not find support in the prior art of record. Kato teaches a range that overlaps the claimed range as indicated above. Kato further teaches that the presence of the indicated metals (including aluminum) leads to deterioration of insulation performance of dielectric films (p. 1-2, [0009]). Thus, one of ordinary skill in the art would find adequate motivation to explore the lower portions of the disclosed range in order to minimize deterioration of insulation performance.
The Applicant argues that Kato fails to provide any guidance to arrive at the claimed ash content of 20 ppm.
As indicated above, Kato teaches a total ash content that is preferably 30 ppm or less. According to Kato, larger amounts of ash lead to deterioration of insulation performance (p. 1, [0008]). This clearly overlaps the claimed range of 20 ppm or less and invites exploration of lower ash content below the preferred upper limit of 30 ppm.
The Applicant argues that the prior art fails to recognize the criticality of the combination of low ash content and low aluminum content. The Applicant points to Inventive Example 1b and Comparative Example 2b as evidence of the criticality of the claimed ranges.
Table 2 does illustrate an increase in dielectric breakdown strength in IE1b compared to CE2b. Although the two examples have the same ash content and both possess a titanium content falling within the claimed range, only IE1b has an aluminum content within the claimed range.
However, 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. Additionally, whether 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 MPEP 716.02(d).
Inventive Example 1b amounts to a single data point falling within the claimed range of ash content and aluminum content. 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. However, data associated with one data point cannot reasonably be extrapolated to the full scope of a broader range.
The example is not reasonably commensurate in scope with the claims, and would not allow one of ordinary skill in the art to determine a trend that could be extended to the full scope of the claims. The Applicant’s arguments with respect to IE1b are therefore not sufficient to establish non-obviousness.
Conclusion
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/ROBERT S JONES JR/ Supervisory Patent Examiner, Art Unit 1762