届满专利的国别差异及其文献计量特征对比分析

Contrastive Analysis on Expired Patents’ National Differences and Bibliometric Characteristics

届满专利是技术高度难以被超越,且市场份额难以被掠夺的高价值专利。然而,在中国国家知识产权局授权的专利中,来自日、美、德、法等国专利权人的发明专利届满率远远高于来自中国专利权人的发明专利。本文利用非参数检验方法,对届满专利的文献计量学特征进行了国别差异分析,并在20年、10年和5年三个时间窗内,对样本领域的发明专利进行了跟踪对比。研究结果发现:①专利的届满率与“被引”无正相关关系,中国专利的整体“被引”水平偏高,但整体届满率反而偏低;②专利的届满率与“施引”有显著的正相关关系;③专利的功能丰富性和普适性是影响专利届满率的重要因素;④非专利文献引用数量并不能客观地反映专利的“科学关联”程度,对专利届满率不具有影响力;⑤专利家族的规模大小是影响专利能否维持到届满的重要因素。

Expired patents are high-value patents with technology that is nearly unsurpassable and whose market share is difficult to plunder. Among the patents authorized by the National Intellectual Property Administration of China, the expiration rate of invention patents from patentees in Japan, the United States, Germany, France, and other countries is much higher than that of invention patents from Chinese patentees. In this paper, a nonparametric test method is used to analyze the national differences of expired patents’ bibliometric characteristics. We then further track and compare invention patents in a specific field at three time windows(20 years ago, 10 years ago, and 5 years ago). The following results are shown. First, there is no positive correlation between expiration rate and citation level. The overall citation level of Chinese patents is higher, but the expiration rate is lower. Second, there is a significant positive correlation between expiration rate and citations. Third, the functional richness and universality of patents are important factors that affect their expiration rate. Fourth, the number of citing non-patent documents does not objectively reflect the degree of scientific association and has no influence on the patents ’ expiration rate. Finally, the size of the patent family is an important factor that affects whether a patent can be maintained until its expiration.