There are many search engines and portals that provide free access to patent documents from agencies around the world. They are mainly useful for locating a patent document you already know about. They are not intended for patentability or prior-art searching, which should be done by professional patent searchers. Most patent office public search sites have terrible interfaces, so patience and determination are essential. Pay special attention to the entry format of patent numbers: most databases won't tolerate any variation in the parsing of numbers and country codes.
- Interactive Patent Coverage Map
- A handy tool for figuring out what patent search sites cover a particular country's patents, along with guidance on using them. If you're unfamiliar with international patent searching, this is a good place to start. (Intellogist)
- Chemical patents worldwide are thoroughly indexed and cross-referenced in Chemical Abstracts. CAS policy is to index the first published patent document (usually a non-U.S. application) in a family. Subsequent granted patents and other applications are listed in the Patent Family table in the full record:
For coverage details, see the CAS Patent Coverage page.
In most cases SciFinder links to the indexed full text patent document via USPTO or Espacenet, but not to other documents in the family. To retrieve a later document, search its number in one of the tools below.
- U.S. Patent and Trademark Office
- Search and download fulltext U.S. patents since 1976 and PDF page images since 1790, plus published applications since 2001. The interface can be confusing; using third-party shortcuts such as pat2pdf can be easier when you need to retrieve a known patent number.
- If you have a patent number, this is a quick and easy shortcut to fetching PDF files of all U.S. patents from the USPTO site without actually going there.
- Google Patent Search
- Search and retrieve full text of all U.S. patents since 1790 and published applications since 2001.
- European Patent Office search site for patents and applications: EP, WIPO/PCT, US, GB, FR, DE, JP, and over 70 countries. You can save PDFs of available documents up to a certain page limit. This is the site SciFinder links to for non-U.S. patents.
- From the German Patent and Trademark Office (Deutschen Patent- und Markenamtes, DPMA). Search patents and applications; links to the full text
patent when available. PDF fulltext must be downloaded one page at a time.
- Search US, EP, JP (abstracts), and WIPO (PCT). Chemical search features are available via SureChem Free.
- Patent Lens
- Full text of over 10 million patent documents from US, Europe, Australia and WIPO, their status and counterparts up to 70 countries.
- Search international patent applications (PCT) from WIPO.
- Portal of the EurAsian Patent Information System, which allows free searching of "EAPO, WIPO, EPO, US, USSR and Russia (since 1924) ... as well as patent documentation of national patent offices of CIS countries including EAPO Member-States." Free number searching but other features are by subscription.
- Canadian Patents Database
- CIPO records from 1869; full text from 1920.
- Japan Patent Office
- The dreadful interface makes this search engine a last resort for finding Japanese patents and applications. A number query must be perfectly entered with codes to work, and the instructions do not help. No PDFs; single page views only; all full text in Japanese. Dates of coverage vary according to type of patent document.
- SIPO - Chinese Patent Office
Basic Patent Information
Queens Univ. Guide
What Every Chemist Should Know about Patents (ACS, 2002)