Prosecution Insights
Last updated: April 19, 2026
Application No. 18/023,713

POLYDIORGANOSILOXANE PREPARATION

Non-Final OA §103§112
Filed
Feb 27, 2023
Examiner
MOORE, MARGARET G
Art Unit
1765
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Dow Silicones Corporation
OA Round
1 (Non-Final)
68%
Grant Probability
Favorable
1-2
OA Rounds
3y 0m
To Grant
83%
With Interview

Examiner Intelligence

Grants 68% — above average
68%
Career Allow Rate
885 granted / 1302 resolved
+3.0% vs TC avg
Strong +15% interview lift
Without
With
+15.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
44 currently pending
Career history
1346
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
57.4%
+17.4% vs TC avg
§102
15.9%
-24.1% vs TC avg
§112
9.0%
-31.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1302 resolved cases

Office Action

§103 §112
DETAILED ACTION Election/Restrictions Applicant's election with traverse of Group I in the reply filed on 11/3/25 is acknowledged. The traversal is on the ground(s) that the claimed process is not taught or suggested by the prior art such that there is unity of invention. This is not found persuasive because the prior art rejection below demonstrates that the process of claim 1 does not contribute over the prior art. Furthermore, the Examiner notes that the poly-mer of claim 11 does not possess a special technical feature over the prior art since a polymer meeting this formula is shown in numerous references, including those cited below. The requirement is still deemed proper and is therefore made FINAL. Claim Interpretation For claim interpretation purposes, the Examiner notes that claim 1 does not require that the end-capping catalyst be added in such a manner. This claim states that it can be added in such a manner. This does not constitute a required step. Also, the term “consisting of” as found in claim 1 limits the process per se, but does not limit the reactants or reaction conditions. Claim Rejections - 35 USC § 112 Claims 1 to 5, 7 to 9 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor regards as the invention. The definition of R 1 is confusing as it is first clearly defined as a monovalent hydrocarbon radical but then subsequently defined as groups that are narrower (such as aryl) and also groups that are outside a monovalent hydrocarbon groups (halogen containing groups). As such the breadth of R 1 is unclear. In claim 8 it is unclear what weight to give the language “prior to use”. Since this is a future intended use clause, it is unclear how to interpret this language. For instance what weight does this language carry if the polysiloxane is stored for 2 weeks or one day? What if the product is shipped and not used for another year or two? Would such a process be embraced by the claim? 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. Claim s 1 to 5 and 7 to 9 are rejected under 35 U.S.C. 103 as being unpatentable over Cooper et al. 3,542,901, in view of Cross et al. 2007/0123640 . Cooper et al. teach a method of making organosilicon compositions which in- clude an alkoxy terminated polydiorganosiloxane. Specifically see the top of column 3 which shows such a siloxane (one having the same structure as in withdrawn claim 11). This teaches that the siloxane is formed by the reaction of an organotrialkoxy sil -ane with a polysiloxane having terminal hydroxyl. This is an endcapping reaction and t he reactants correspond to the two starting materials in the claimed reacting step. Line 14 teaches that this is performed in the presence of an amine catalyst. This differs from that claimed in that it does not specifically teach a n amidine or guanidine group containing compound as claimed. Cross et al. teach a similar process in which a hydroxyl terminated siloxane is reacted with a silane compound to endcap the siloxane. Paragraph 88 teaches amine endcapping catalysts including compounds meeting the claimed endcapping catalyst , such as DBU, diphenylguanidine, pyrazine and 2-ethyl-4-methyl imidazole. These also meet the requirement of claim 2 and the 1,8-diazobi-cyclo[5.4.0]undec-7-ene in claim 3. As such one having ordinary skill in the art would have been motivated by the general teaching of an amine endcapping catalyst in Cooper et al. to look to known teachings of such catalysts. This would lead the skilled artisan to the teachings of Cross et al. such that the use of amine catalysts meeting that found in claims 1 to 3 would have been obvious. Note that the amount of catalyst found in paragraph 89 of Cross et al. embraces the claimed range such that selecting an amount of catalyst as claimed would have been within routine experimentation of this teaching. In this manner these claims are rendered obvious. For claim 4, note that static mixers are extremely common and well - known device for the continuous mixing of materials such that the skilled artisan would have found the use of such a common mixer to have been obvious in the reaction of Cooper et al. For claim 5, note that both references are silent as to such further processing and, as such, the skilled artisan would have no reason to perform such steps if not necessary. For claim 7, note that Cooper et al. do not teach a temperature but the skilled artisan would have found it obvious to adjust the temperature within an optimum range in an effort to expedite and efficiently perform the process of Cooper et al. For claim 8 , the Examiner notes that the breadth of this claim is unclear but it would have been obvious to the skilled artisan to prepare a quantity of alkoxy termin-ated polysiloxanes and store it prior to usage for convenience or efficiency such that storing the product 3 to 7 days would have been obvious. For claim 9, using an excess of the alkoxysilane reactant to promote a more complete reaction would have been well within the skill of the ordinary artisan. Such a process would then result in excess alkoxysilane as required in this claim. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILLIN "Examiner name" \* MERGEFORMAT MARGARET MOORE whose telephone number is FILLIN "Phone number" \* MERGEFORMAT (571)272-1090 . The examiner can normally be reached on FILLIN "Work Schedule?" \* MERGEFORMAT Monday to Friday, 10 am to 5 pm . If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Heidi Kelly, can be reached at 571-270-1831. Mgm 11/25/25 /MARGARET G MOORE/ Primary Examiner, Art Unit 1765
Read full office action

Prosecution Timeline

Feb 27, 2023
Application Filed
Nov 25, 2025
Non-Final Rejection — §103, §112
Apr 10, 2026
Interview Requested
Apr 16, 2026
Examiner Interview Summary
Apr 16, 2026
Applicant Interview (Telephonic)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601178
BONDING ADHESIVE AND ADHERED ROOFING SYSTEMS PREPARED USING THE SAME
2y 5m to grant Granted Apr 14, 2026
Patent 12595339
PREPARATION OF ORGANOSILICON COMPOUNDS WITH ALDEHYDE FUNCTIONALITY
2y 5m to grant Granted Apr 07, 2026
Patent 12590185
RAPID-CURING TWO-COMPONENT SILICONE COMPOSITION HAVING A LONGER MIXER OPEN TIME
2y 5m to grant Granted Mar 31, 2026
Patent 12583975
UV-CURABLE ORGANOPOLYSILOXANE COMPOSITION AND USE THEREOF
2y 5m to grant Granted Mar 24, 2026
Patent 12577351
Increasing the molecular weight of low molecular weight alpha,omega-polysiloxanediols
2y 5m to grant Granted Mar 17, 2026
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
68%
Grant Probability
83%
With Interview (+15.1%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 1302 resolved cases by this examiner. Grant probability derived from career allow rate.

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