If the priority of an earlier application can be obtained upon the filing of a Patent Cooperation Treaty (PCT) international application, the time for the PCT international application will be advanced, and furthermore, advantages can be undoubtedly brought for the examination of a national application entering the national phase based on the PCT international application. For example, enjoying earlier filing date can bring about benefits for a national application entering the national phase based on such PCT international application in terms of the evaluation of novelty and creativity. The author will discuss below the topic about the claim for the priority of earlier Chinese applications for PCT international applications.

I. Preconditions for Claiming Priority

As to time, a PCT international application shall be filed within 12 months upon the filing date of an earlier Chinese application, and the following shall be stipulated in the PCT: no priority will be enjoyed if an earlier Chinese application whose priority is claimed for a PCT international application falls under one of the following circumstances: having claimed foreign priority or Chinese priority; patent rights having been granted; being a divisional application filed as required.

II. Several Cases of Claiming an Earlier Chinese Application for a PCT International Application

1. General sense of an earlier Chinese application for a PCT international application

If an earlier Chinese application whose priority is claimed for a PCT international application is of a general sense, that is, such earlier Chinese application has neither claimed priority over other applications nor been claimed priority by other applications. If the content of a PCT international application is identical to that of an earlier Chinese application, such PCT international application enjoying the priority of such earlier Chinese application is not problematic; but if the content of a PCT international application is not the same as that of an earlier Chinese application, the judgment on whether such PCT international application can enjoy the priority will vary from one subsequent nation to be entered to another, which is connected with the degree of strictness in different nations as to the judgment about whether to enjoy priority.

For example, the technical plan provided in an earlier Chinese application is: 1+2+3. If the technical plan recorded in a PCT international application is identical to it, namely 1+2+3, then such PCT international application enjoying the priority of such earlier Chinese application is not problematic. But if the technical plan recorded in a PCT international application is 1+2+4, of which 4 is a relatively obvious alternative technical means of 3, and no 1+2+4 is recorded throughout the application document of the earlier Chinese application, the result of whether a priority can be enjoyed will be different due to varied degree of strictness of examination in different nations, when such PCT international application is entering in the national phase. For example, priority may not be admitted in Europe because of relatively stricter examination standard and may be admitted in the U.S. because of looser examination standard. Therefore, certain risks exist for obtaining priority of an earlier Chinese application.

2. Circumstance where the earlier Chinese application claimed by a PCT international application has already had its priority claimed

Generally the circumstance is that application A was filed in China first, and later the applicant made modifications to the application A (adding some technical content) and filed application B based upon application A. When filing application B, the applicant had enjoyed the priority of application A. The applicant only claimed priority of application B when filing a PCT international application.

In this case, we believe that the priority claim is improper, because when priority of application B is claimed for the PCT international application, only priority of the part of technical content of application B which was added to application A can be claimed, and no priority is admitted for the same part of technical content of application B as that of application A for application B is not the first application. Therefore, in order to ensure a full protection of all related technical plans, simultaneous applications for priority of both application A and application B are required when a PCT international application is filed. It should be explained that if a claim for priority of application A is missed when a PCT international application is filed, the claim for priority can be added within the priority period.

For example, application A was filed in China first with the technical plan: 1+2+3, and later the applicant found that application A could be improved. Then application B, an improved application to application A, was filed based upon application A. The technical plan of application B is: 1+2+3 / 4, among which 4 is an alternative means of 3 with better effects. Within the priority period, the priority of application A was claimed when application B was filed, and only priority of application B was claimed when a PCT international application was filed based upon the Chinese application.

In this case, because it is not the first filing for the technical plan 1+2+3, the PCT international application will not enjoy the priority of the technical plan 1+2+3 recorded in application B and may only enjoy the priority of the technical plan 1+2+4 recorded in application B. If no claim for priority of application A is added within the priority period, when a subsequent application based upon the PCT international application entries the national phase, application A will be an existing technology which can be used to evaluate novelty and creativity upon the examination of the application in national phase, because the PCT international application has no priority of application A. Because of the extremely high similarity between application A and application B (namely the PCT international application and the subsequent application in the national phase), to use application A as an existing technology to evaluate the application in national phase is fatal, that is, this may lead to rejection of the application.

3. Circumstance where the earlier Chinese application claimed by a PCT international application has already had its priority claimed

In this case, the earlier Chinese applications are the same as those in the above case 2, that is, application A was filed in China first, and later the applicant made modifications to application A (adding some technical content) and filed application B based upon application A. When filing application B, the applicant had enjoyed the priority of application A. The difference from the above case 2 is that only priority of application A was claimed when a PCT international application was filed.

In this case, it is obvious that, according to the above analysis, the technical part of application B which was added to application A will not obtain good protection due to only the priority of application A being claimed in the PCT international application, and furthermore, no entry of the said technical part into the PCT international application can be made by reference in the subsequent phase because nothing in application A is related to the said technical part. Therefore, such PCT international application provides incomplete protection of the patent technical plan.

So in this case, if such PCT international application is still within the priority period of application B, is it necessary to make addition to the claim for priority of application B for the PCT international application? The answer is that, at that time, it is meaningless to make addition to the priority claim, because the technical part of application B which was added to application A was not included in the PCT international application.

To be specific, it is the case that application A was filed in China first with the technical plan: 1+2+3, and later the applicant found that application A could be improved. Then application B, an improved application to application A, was filed based upon application A. The technical plan of application B is: 1+2+3 / 4, among which 4 is an alternative means of 3 with better effects. Within the priority period, the priority of application A was claimed when application B was filed, and only priority of application A was claimed when the PCT international application was filed based upon the Chinese application.

According to the above analysis, the technical plan: 1+2+4 in the improved application B does not receive good protection, and furthermore, no entry of the said technical plan to the PCT international application can be made by reference in the subsequent phase and it is useless to make addition to the claim for priority of application B. The only possible remedy to this case is to file another PCT international application based upon both application A and application B (provided that both applications are still within the priority period), but such remedy undoubtedly will greatly increase the application expenses.

III. Recovery of Priority of an Earlier Chinese Application for a PCT International Application

Within two months upon the expiration of the priority period, an application for recovery of priority of an earlier Chinese application for a PCT international application can be filed.
If both the priority period and the two-month recovery period expire, the following ways can be taken for recovery if the applicant still wants to claim the priority of an earlier Chinese application: (1) to file a request for recovery of priority on the ground of "unintentional delay". But it should be explained that most of the PCT signatory nations will not accept such request for recovery of priority; or (2) to file a request for recovery of priority on the ground of "reasonable care". By using such request, although more sufficient reasons are required to file and much more complete and comprehensive proof materials are needed, the possibility of acceptance by most of the PCT signatory nations will be increased significantly.

IV. Conclusion

It is very important to claim the priority of an earlier Chinese application when filing a PCT international application based upon the earlier Chinese application, because it will not only affect the destiny of the patent application when it enters the national phase, but may also greatly increase the patent application expenses, both of which are definitely detrimental to the patent applicant. Therefore, when the priority of an earlier Chinese application is claimed for the filing of a PCT international application, the patent applicant or the patent agency is required to have not only relatively sophisticated abilities to record the details of cases, but the systematic legal knowledge of the filing of PCT international applications.