Prosecution Insights
Last updated: April 19, 2026
Application No. 18/692,905

ULTRAHIGH-MOLECULAR-WEIGHT POLYETHYLENE POWDER AND MOLDED ARTICLE PREPARED BY MOLDING SAME

Non-Final OA §103§112
Filed
Mar 18, 2024
Examiner
REDDY, KARUNA P
Art Unit
1764
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Asahi Kasei Kabushiki Kaisha
OA Round
1 (Non-Final)
42%
Grant Probability
Moderate
1-2
OA Rounds
3y 8m
To Grant
51%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
350 granted / 829 resolved
-22.8% vs TC avg
Moderate +9% lift
Without
With
+8.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
62 currently pending
Career history
891
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
54.1%
+14.1% vs TC avg
§102
12.0%
-28.0% vs TC avg
§112
20.3%
-19.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 829 resolved cases

Office Action

§103 §112
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 . The examiner assigned to the current application has been changed. The new examiner's name and contact information are stated at the end of this action. Applicant is requested to take note of the change. This office action is in response to the amendment filed 10/31/2025. Claims 1-20 are currently pending in the application. Election/Restrictions Applicant's election with traverse of group I, drawn to claims 1-10 and 15-19, in the reply filed on 10/31/2025 is acknowledged. The traversal is on the ground(s) that applicant has elected claims directed to a product and requests that when all product claims are subsequently found allowable, withdrawn process claims that include all limitations of allowable product claims be considered for rejoinder. This is not found persuasive because claims drawn to elected invention are not in condition for allowance. However, examiner would consider the rejoinder when claims drawn to elected invention are in condition for allowance. The requirement is still deemed proper and is therefore made FINAL. Claims 11-14 and 20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 (election) requirement in the reply filed on 10/31/2025. Claim Objections Claims 2-3 and 15 are objected to because of the following informalities: Claims 2 (line 2), 3 (line 2) and 15 (line 2) recite “standard deviation s” and should read “standard deviations”. Claim 3 recites “the standard deviation s”. For consistency within the claims applicant is advised to rephrase it as “standard deviations” Appropriate correction and/or clarification are 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. Claims 1-10 and 15-19 are 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 1 recites “ultrahigh-molecular-weight polyethylene”. The term “ultrahigh is a relative term”. It is not clear what the molecular weight of polyethylene is in the present instance. Hence, metes and bounds of present claims cannot be ascertained by one of ordinary skill in art prior to the filing of present application. Claims 2-10 and 15-19 are subsumed by the dependence either directly or indirectly on independent claim 1. Claim 1 recites the limitation "the target ultrahigh-molecular weight polyethylene powder" in line 6. There is insufficient antecedent basis for this limitation in the claim. Claims 2-10 and 15-19 are subsumed by this rejection because of the dependence either directly or indirectly on independent claim 1. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-4, 6-10, 15-16 and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Tsujimoto (US 2019/0194431 A1 - hereafter Tsujimoto ‘431). Regarding claims 1 and 6, Tsujimoto ‘431 teaches ultra-high molecular weight polyethylene powder (i.e., reads on ultrahigh molecular weight polyethylene powder in present claim 1) having a viscosity average molecular weight of 10 *104 or higher and 1000 * 104 or lower (abstract). The viscosity average molecular weight was determined from intrinsic viscosity (η) according to the following expression Mv = (5.3 * 104) * ( η)1.49 (paragraph 0161). See example 1, wherein viscosity average molecular weight is 350 * 104 (Table 1). Hence, intrinsic viscosity is calculated to be about 17 dL/g (i.e., reads on the intrinsic viscosity IV in present claim 1). Tsujimoto ‘431 fails to disclose the average value of swelling onset temperature. However, Tsujimoto ‘431 in the general disclosure teach that powder having a temperature range of 170 0C or lower in which a torque value reaches ½ of the maximum torque value is swollen (i.e., state where the powder is sufficiently impregnated with liquid paraffin) at a relatively low temperature and early after the start of kneading. A molecular chain can be disentangled at a low temperature, and a homogeneous kneaded gel can be obtained. As a result, a spun thread can be wound at a high speed (paragraph 0050). Therefore, in light of the teachings in general disclosure of Tsujimoto ‘431 and given that ultra-high molecular weight polyethylene powder is impregnated with liquid paraffin resulting in swelling of the powder at low temperature, one skilled in art prior to the filing of present application would have a reasonable basis to expect average value Ts of swelling onset temperature of the ultra-high molecular weight polyethylene powder, of Tsujimoto ‘431 to fall within the range of 900C to more and 1300C or less, under the conditions specified in the present claims, absent evidence to the contrary. Alternatively, Tsujimoto ‘431 teaches that average particle size (D50) of ultra-high molecular weight polyethylene powder is in the range of 80 microns or larger and 250 microns or smaller (paragraph 0063). When particle sizes corresponding to cumulative 10%, 50% and 90% from the minor diameter side of a cumulative particle size distribution are defined as D10, D50 and D90, respectively, the ultra-high molecular weight polyethylene powder has D10/D50 of 0.40 or more and D90/D50 of 2.0 or less (paragraph 0064). The D10/D50 and D90/D50 ratio can be controlled by the particle size and particle size distribution of the ultra-high molecular weight polyethylene powder (paragraph 0067). The particle size distribution can be controlled by adjusting the size and/or amount of carrier catalyst carrier for use in polymerization. The size of catalyst carrier is adjusted to adjust the particle size of the produced ultra-high molecular weight polyethylene powder (paragraph 0069). Therefore, given that particle size can be controlled by adjusting the size and/or amount of catalyst for use in polymerization, polymer powder when swollen at a relatively low temperature is disentangled and the spun thread can be wound at a high speed, it would have been obvious to one skilled in art prior to the filling of present application to adjust D10, D50 and D90 particle size distribution to any value including that which would result in swelling onset of low temperature (such as in present claims), absent evidence to the contrary. Regarding claims 2, 3 and 15, Tsujimoto ‘431 teaches that particle size can be controlled by adjusting the size and/or amount of carrier catalyst carrier for use in polymerization. The size of catalyst carrier is adjusted to adjust the particle size of the produced ultra-high molecular weight polyethylene powder (paragraph 0069). Therefore, given that particle size can be controlled by adjusting the size and/or amount of catalyst for use in polymerization, polymer powder is swollen at a relatively low temperature, it would have been obvious to one skilled in art prior to the filling of present application to adjust D10, D50 and D90 particle size distribution to any value including that which would result in swelling onset of low temperature (such as in present claims) including a standard deviation of the ultra-high molecular weight polyethylene powder having particle sizes of D10, D50 and D90 to 50C or less (as in present claim 2) and 2.40C or less (as in present claims 3 and 15) absent evidence to the contrary. Regarding claims 4 and 16, Tsujimoto ‘431 teaches that content of comonomer is preferably 1% by mol or less (paragraph 0031). Regarding claims 6 and 18, Tsujimoto ‘431 teaches that ultra-high molecular weight polyethylene powder has D10/D50 of 0.40 or more and D90/D50 of 2.0 or less (paragraph 0064). The upper limit of D10/D50 is preferably 0.70 or less and lower limit of D90/D50 ratio is preferably 1.0 or more (paragraphs 0065-0066). Hence, ratio of D90/10 is calculated to be in the range of 1.45 to 5.0 (i.e., overlaps with the D90/D10 in present claims 6 and 18). Case law holds that when the range of instant claims and that disclosed in prior art overlap, a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). Regarding claims 7 and 19, Tsujimoto ‘431 teaches that average particle diameter (D50) is in the range of 80 microns or more and 250 microns or smaller (paragraph 0063). The particle size can be controlled by adjusting the size and/or amount of carrier catalyst carrier for use in polymerization. The size of catalyst carrier is adjusted to adjust the particle size of the produced ultra-high molecular weight polyethylene powder (paragraph 0069). Therefore, it is the Office’s position that it is within the scope of one skilled in art prior to the filing of present application to adjust the D10 and D90 to any size including D10 of 30 microns or larger and D90 of 425 microns or smaller, absent evidence of unexpected results. Regarding claims 8-10, Tsujimoto ‘431 teaches that molded article is obtained using ultra-high molecular weight polyethylene powder (i.e., reads on shaped article in present claim 8). The molded article is suitable for a microporous membrane for lithium ion secondary battery separators (i.e., reads on shaped article is a separator for secondary battery in present claim 9) and a fiber (paragraph 0149) which reads on the shaped article is a fiber in present claim 10). Claims 5 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Tsujimoto (US 2019/0194431 A1 - hereafter Tsujimoto ‘431) in view of Tsujimoto et al (US 2021/0017363 A1 - hereafter Tsujimoto ‘363). The discussion with respect to Tsujimoto ‘431 in paragraph 13 above is incorporated here by reference. Additionally, Tsujimoto ‘431 teaches that silicon content is 1 ppm or more and 80 ppm or less (paragraphs 0091-0092) which overlaps with the silicon content in present claims 5 and 17. Tsujimoto ‘431 are silent with respect to the content of titanium (Ti) and aluminum (Al). However, Tsujimoto ‘363 in the same field of endeavor teach ultra-high molecular weight polyethylene powder (abstract) having a titanium (Ti) content of 0.1 ppm or higher and 5 ppm or lower (i.e., overlaps with the Ti content in present claims 5 and 17), aluminum (Al) content of preferably 0.5 ppm or higher and 10 ppm or lower (i.e., overlaps with the Al content in present claims 5 and 17). The ultra-high molecular weight polyethylene powder having the amounts of metals thus adjusted have better thermal stability and produces a molded article having a better long term stability (paragraph 0069). Case law holds that when the range of instant claims and that disclosed in prior art overlap, a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). See MPEP § 2144.05. Therefore, in light of the teachings in Tsujimoto ‘363 and case law, it would have been obvious to one skilled in art prior to the filing of present application to adjust the content of Ti and Al in the overlapping ranges, for above mentioned advantages. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to KARUNA P REDDY whose telephone number is (571)272-6566. The examiner can normally be reached 8:30 AM to 5:00 PM M-F. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Arrie (Lanee) Reuther can be reached at 571-270-7026. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /KARUNA P REDDY/Primary Examiner, Art Unit 1764
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Prosecution Timeline

Mar 18, 2024
Application Filed
Jan 12, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
42%
Grant Probability
51%
With Interview (+8.8%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 829 resolved cases by this examiner. Grant probability derived from career allow rate.

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