The case of the superconductor industry. Faced with the energy crisis, civil society demands that solutions be found. Superconductivity is one such solution and is attracting the attention of States and companies alike. Given its specific characteristics, this particular field of research cannot be controlled by a sole organisation. À commitment needs to be made collectively in order to find or to maintain international competitiveness. The involved firms deposit a great number of patents and form alliances at the same time. This article clarifies the role of property rights in partnerships and is based on a case study in the superconductor industry. This technology requires recognition on a world wide scale. This explains the choice of patent filing areas, the decisions pertaining to the sharing of technology and the necessity of establishing criteria for evaluation. In a partnership framework, the patent is a way of measuring the competence of those involved and it is also a mediation instrument. In addition it enables them to be structured and gives an indication of the strategies in place through the independence or co-ownership of patents. This study shows the Japanese exception concerning joint patents which may be explained not only by the voluntarist policies of the Japanese authorities who have set up this sector as a national priority and have provided the institutional backing necessary to the technological development, but also by the role of culture involving stable, lasting relationships based on trust. The key role of patent strategies in firm partnership strategies is obvious but goes beyond the traditional uses within a climate which is favourable to innovation.