Prosecution Insights
Last updated: April 19, 2026
Application No. 18/246,740

POLYACETAL COPOLYMER AND METHOD OF MANUFACTURING THE SAME

Non-Final OA §103
Filed
Mar 27, 2023
Examiner
FANG, SHANE
Art Unit
1766
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Polyplastics Co. Ltd.
OA Round
1 (Non-Final)
76%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
95%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
1136 granted / 1491 resolved
+11.2% vs TC avg
Strong +19% interview lift
Without
With
+19.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
51 currently pending
Career history
1542
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
43.9%
+3.9% vs TC avg
§102
24.3%
-15.7% vs TC avg
§112
16.5%
-23.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1491 resolved cases

Office Action

§103
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 . DETAILED ACTION All the references cited in the International Search Report have been considered. None is anticipatory. The most pertinent of these references have been applied below. Election/Restrictions The applicant has elected Group I (claims 1-4) without traverse. This restriction is made FINAL. See previous action for the reasons of applying restriction. 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 of this title, 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. Claim(s) 1-4 is (are) rejected under 35 U.S.C. 103(a) as being unpatentable over Tsugai et al. (JP2006249445) in view of Tajima et al. (US 6426393), both listed on IDS and ISR, and further in view of Hirano et al. (US 20160090445). As to claims 1-4, Tsugai (abs., claims, examples) discloses a process for producing polyacetals for molding (2, 4) comprising polymerizing (Ex.1, Table 1) trioxane (a, 100 parts), comonomer 1,3-dioxolane (c, a cyclic acetal,1.23 parts), and butyl glycidyl ether (b-1, 1 part) and methylal (a linear formal compound): PNG media_image1.png 200 400 media_image1.png Greyscale . Methylal, as a molecular weight modifier, is added at 1 ppm to 1000 ppm per mol of trioxane (23), or 1.11 mmol to 1110 mmol per 100g (1.11 mol) of trioxane . Tsugai is silent on the chlorine content of the aliphatic glycidyl ether of claim 1. In the same area of endeavor of producing polyacetal molds (6:10-15), Tajima (abs., claims, examples) discloses a process of producing polyacetals comprising polymerizing trioxane, butyl glycidyl ether, and cyclic acetal such as 1,3-dioxolane (claims 1, Ex.1). Tajima discloses using a butyl glycidyl ether having an exemplary (Ex.1) 0.03 wt% (300 ppm, falling within the claimed range of instant claim 1) renders improved flowability, moldability, and thermal stability in the resultant polyacetal (1:55-68, 2:1-5, 3:20-30). Therefore, as to claims 1-4, it would have been obvious to one of ordinary skill in the art to have modified the process disclosed by Tsugai and replaced the glycidyl ether with Tajima’s butyl glycidyl ether having 300 ppm chlorine, because the resultant process would yield a polyacetal with improved flowability, moldability, and thermal stability. Tsugai teaches the trioxane contains impurities such as water and methanol (18) but is silent on the water and methanol content of trioxane in claim 1. However, it is well known that impurities, such as water and methanol, are inevitably produced during the industrial production of trioxane (≤10 ppm) and 1,3-dioxolane (≤50 ppm), as taught by Hirano (37-38). Since the “ppm” is commonly referred as wt%, as obviously recognized by one of ordinary skill in the art, the mol% of water and methanol would be < 0.11 (10/90.8) mmol in 1g of Tsugai’s trioxane and <0.66 (50/74.8) mmol in 1g of Tsugai’s 1,3-dioxolane. Hirano is an analogous art, because Hirano (claims, 30, 68, examples) teaches a process of polyacetal comprising trioxane, methylal, and 1,3-dioxolane for producing molds. The corresponding “a” of claim 1 is 100+1+1.23=102.23 g in Tsugai’s Ex. 1; the corresponding “b” (methylal) of claim 1 is 1.11 mmol to 1110 mmol. The corresponding “c”+ “d” of claim 1 (water and methanol content of trioxane, 1,3-dioxolane,and butyl glycidyl ether) would be <11.8 mmol (0.11*100+0.66*1.23) in view of Hirano and Tsugai’s Ex. 1. Thus combining Tsugai, Hirano, and Tajima would yield a corresponding range of “b+c+d/a” of claim 1 as <0.1-11 mmol/g (overlapping with claimed range of claim 1, 1.5-7 mmol/g) by the following calculation: PNG media_image2.png 200 400 media_image2.png Greyscale It has been found that where claimed ranges overlap ranges disclosed by the prior art, a prima facie case of obviousness exists - see MPEP 2144.05. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHANE FANG whose telephone number is (571)270-7378. The examiner can normally be reached on Mon-Thurs. 8am-6pm. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Randy Gulakowski can be reached on 571.572.1302. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SHANE FANG/Primary Examiner, Art Unit 1766
Read full office action

Prosecution Timeline

Mar 27, 2023
Application Filed
Jan 31, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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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
76%
Grant Probability
95%
With Interview (+19.0%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 1491 resolved cases by this examiner. Grant probability derived from career allow rate.

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