Facts recap
- DE-C (German utility model application) filed Dec 2023, directed to solution of X in water, published Mar 2024.
- EP-C filed Nov 2024, claims priority from DE-C. Claims:
- Claim 1: solution of X (generic)
- Claim 2: solution of X in water
- Claim 3: solution of X in alcohol
- A scientific publication in Sep 2024 disclosed solution of X in water.
Priority questions are assessed per Art. 87–89 EPC: a claim enjoys a priority date only for subject-matter that is the same invention as disclosed in the priority filing.
Answers to the statements
a) Priority from a German utility model for EP-C — True
Art. 87(1) EPC expressly states that if a person has duly filed an application for a patent, a utility model or a utility certificate, they enjoy a right of priority for filing a European patent application in respect of the same invention within 12 months.
So, in principle, DE-C can be a valid priority application for EP-C (and the timing “Dec 2023 → Nov 2024” is within 12 months).
b) Effective date of claim 3 — True
Claim 3 relates to solution of X in alcohol. Priority is only valid for subject-matter that the skilled person can derive directly and unambiguously from the priority application as filed (“same invention”).
Given DE-C is directed to solution in water, claim 3 (alcohol) is not disclosed there → no priority for claim 3. Therefore, claim 3’s effective date is the filing date of EP-C (Nov 2024).
(Separately: claim 2 (water) is the “natural” candidate for priority; claim 1 may or may not be priority-entitled depending on whether DE-C discloses the generic “solution of X” as such, or only “solution of X in water”.)
c) Dependent claim must share independent claim’s priority — False
Priority is assessed claim-by-claim and even within one claim: Art. 88(2) EPC states that “where appropriate, multiple priorities may be claimed for any one claim.”
So even if claim 1 were entitled to a priority date (fully or partially), a dependent claim can:
- have the same priority date,
- have a different priority date, or
- have no priority at all, depending on what it adds and whether that added subject-matter is disclosed in the priority application.
Your own fact pattern illustrates this: claim 2 (water) is aligned with DE-C, while claim 3 (alcohol) is not.
d) First filing for “solution of X in alcohol” — True
The “first filing” concept is subject-matter specific: for the invention “solution of X in alcohol”, there is no earlier application by company C on that subject-matter (DE-C is water). Therefore, EP-C is the first filing for the alcohol solution.
Exam Tip:
When you see a priority puzzle with multiple embodiments/solvents:
- Start from Art. 87(1) EPC: priority can come from utility models too.
- Apply “same invention” (direct and unambiguous disclosure) separately for each claim.
- Remember Art. 88(2) EPC: a single claim can have multiple/partial priorities, so dependent claims are not automatically tied to the independent claim’s priority.
Legal Disclaimer
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