Derwent Innovations Index provides both Derwent World Patents Index and Derwent Patents Citation Index.
This index is for chemistry, electron, and mechanical engineering.

You can cross-search with other databases by Web of Science

Japan Platform for Patent Information offers the public access to IP Gazettes of the JPO free of charge through the Internet.

J-GLOBAL is a project to connect an array of information, including information on research pappers and patents, analyze and visualize such information and provide knowledge that can help the national government and private companies in the decision-making to develop policies and strategies.

CAS SciFinder-n is a research discovery tool that allows college students and faculty to access a wide diversity of research from many scientific disciplines, including biomedical sciences, chemistry, engineering, material science, agricultural science, and more.