Recent Trends Concerning Disclaimers (Negative Limitations): 

1) Background:

According to the Japanese Patent Law, amendments should be made “within the scope of the matters described in the specification or drawings.”

In 2018, the Grand Panel Decision at the IP High Court established that the “matters described in the specification or drawings” refer to technical matters that can be derived by comprehensively considering all the descriptions in the specification or drawings. The decision also established that an amendment can be considered made “within the scope of the matters described in the specification or drawings” if it does not introduce new technical matters in relation to the technical matters thus derived. The Grand Panel Decision also ruled that amendments to exclude a limitation(s) (hereinafter referred to as the “disclaimer*”) should also be judged based on whether they introduce new technical matters in relation to the technical matters described in the specification, etc.

• *The JPO defines that the term “disclaimer” refers to a claim that excludes certain elements from the subject matter described in the claim while retaining the wording of the described elements.
• Ex. Inorganic salts containing Na ions as cations (except when the anion is CO₃⁻).

In 2010, the Japan Patent Office (JPO) revised the Examination Guidelines to align with the Grand Panel Decision.

2) Previous Trends:

The “disclaimer” has proven effective as a means of amendment to overcome the grounds for rejection based on lack of novelty or inventive step, not only in chemical engineering fields but also in non-chemical engineering fields such as electrical engineering, mechanical engineering, and software engineering.

While the usefulness of such a disclaimer has been recognized, concerns about their abuse are growing alongside their expanding use, especially against inventive step rejections. This was due to the tendency to be perceived as less likely to constitute the addition of new matter and the broader scope of a claim compared to adding a limitation.

3) Recent Trends:

After 2024, the IP High Court has seen cases where it did not accept applicants’ arguments that inventive step existed based on a disclaimer.

In 2025, the JPO issued the following statement regarding the disclaimer:

(1) Regarding Inventive Step

When an invention does not significantly differ from the cited invention in terms of technical concept, a “disclaimer” rarely resolves the rejection reason of lack of inventive step.

(2) Regarding Addition of New Matter

It is necessary to explain in the statement of opinion, etc., that the technical concept has not changed due to the disclaimer and that inventive step existed even before the amendment.

(3) Regarding Clarity

If the “disclaimer” constitutes a significant part of the invention or if the description borrows expressions from the prior art, there is a risk of lack of clarity.

4) Future Practice:

It is anticipated that the JPO will increasingly adopt a more cautious and stringent approach in its examination of disclaimer. We believe that a disclaimer remains an effective strategy for overcoming prior-art rejections in certain situations. If we determine that a disclaimer is necessary and effective, we will propose one. In that case, we will also address the new matter and clarity issues with even greater care than before.

We believe the above comments will be clear to you.  Should you have any further questions, please do not hesitate to contact us.