Although the total production of nitrile rubber is relatively modest, it comes in a wide variety of grades and finds extensive applications; in recent years, global consumer demand for nitrile rubber has grown at a slow pace. Domestically, nitrile rubber production facilities are small in scale, with high raw-material consumption and energy intensity, resulting in output that fails to meet market needs; consequently, imports remain the primary means of bridging the supply gap.

Among the five major types of adhesives, China Petroleum has the lowest number of patent applications, yet it has established a research and development advantage.

The number of patent applications for nitrile rubber is one order of magnitude lower than that for other types of rubber; at its peak, annual filings totaled only about 60, whereas even the lowest annual filing volume for other rubber types exceeds 100. From a trend perspective, domestic patent applications for nitrile rubber have been on the rise since 2000, while international patent applications for nitrile rubber have been declining since the same year.

The main Chinese patent applicants for nitrile rubber are China National Petroleum Corporation, Bayer AG, and LANXESS AG, while foreign patent applications are predominantly filed by Japanese companies. China National Petroleum Corporation enjoys certain advantages in the development of new nitrile rubber products. Its Lanzhou Petrochemical Company is highly active in the research and development of nitrile rubber, having commissioned a 200-ton-per-year pilot-scale production unit for powdered nitrile rubber, with products capable of replacing imported powdered nitrile rubber; carboxylated nitrile rubber latex for impregnation has already been launched on the market; highly saturated hydrogenated nitrile rubber has also been successfully developed; and liquid hydroxyl-terminated nitrile rubber is now being produced in bulk. Currently, the major producers of nitrile rubber are Germany, Japan, and South Korea. The principal foreign patent applicants include Japan’s NOK Sealing Components Co., Ltd., Koyo Rubber Co., Ltd., Sumitomo Rubber Industries, Ltd., Toyo Tire & Rubber Co., Ltd., Riken Co., Ltd., and Japan Synthetic Rubber Co., Ltd., among others.

Domestic research is highly random, while foreign research focuses on a few hot topics.

Foreign patents on nitrile rubber primarily focus on nitrile/resin blends. In contrast, domestic nitrile rubber patent technology is mainly concentrated on the preparation of oil-resistant or sealing-component-grade nitrile rubber, hydrogenated nitrile rubber, powdered nitrile rubber, and liquid nitrile rubber (C08F236), with no core technologies specific to nitrile rubber itself.

Foreign patents on nitrile rubber technology primarily focus on applications of nitrile rubber (C08L23), accounting for 33% of all applications. Among these, Japan’s NOK has filed the largest number of applications, mainly concerning compositions of nitrile rubber or hydrogenated nitrile rubber with PVC; Sumitomo Rubber Industries, Inc., on the other hand, concentrates on developing mixtures of nitrile rubber and phenolic resins; while Yokohama Rubber Co., Ltd. predominantly holds patents related to rubber compositions for pneumatic tires (C08L21). As for nitrile rubber polymerization technology (C08F236), only Goodyear Tire & Rubber Company has shown involvement.

The trends in nitrile rubber technology development differ between China and other countries. In China, the number of patent applications for nitrile rubber processing and application technologies (C08L) has been on the rise since 2003, whereas internationally, after peaking in 2000, the number of such applications has declined sharply. Research on nitrile rubber polymerization (C08F) technology in China is characterized by considerable randomness and lacks a clear developmental pattern. In contrast, the average annual number of patent applications for nitrile rubber polymerization technology abroad has remained stable at around five, with the focus primarily on the preparation of carboxylated nitrile rubber and hydrogenation of nitrile rubber.

Product demand is relatively low; R&D focuses on high-end solutions and applications.

China’s nitrile rubber production capacity is approximately 90,000 tonnes per year, with patent technologies primarily covering the preparation of powdered nitrile rubber, liquid nitrile rubber, and hydrogenated nitrile rubber, as well as the processing and application of nitrile rubber.

From the perspective of nitrile rubber demand, the production and consumption volumes of powdered nitrile rubber, liquid nitrile rubber, and hydrogenated nitrile rubber are all relatively small. In 2008, domestic market demand for powdered nitrile rubber was approximately 2,000 tonnes, while the annual production capacity for liquid nitrile rubber was only 500 tonnes. Globally, the annual production capacity for hydrogenated nitrile rubber stands at just 22,000 tonnes, with consumption levels hovering around a few thousand tonnes. Given the overall modest demand for these nitrile rubber grades, China’s national intellectual property strategy for nitrile rubber should prioritize innovation at the source by developing high-value-added nitrile rubber products and strengthening R&D on core technologies as well as patent protection.

Modification is one of the key development directions for nitrile rubber. One-third of foreign patents are related to blending and modifying nitrile rubber, with the technology primarily focusing on the compounding of nitrile rubber with synthetic resins (such as PVC) to produce various thermoplastic elastomers. Chinese nitrile rubber manufacturers need to intensify research on blending and modifying nitrile rubber to meet the demands of rubber products and expand the application areas of nitrile rubber.