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Information on Patents for Researchers: Overview

A guide to information on patents for researchers

What is a Patent

A patent is a legal title granting an inventor the right to exclude others from making, using or selling the claimed invention. The duration of a patent in the U.S.A is 20 years from the date of filing. A patent may be granted for "any new and useful process, machine, manufacture or composition of matter, or any new and useful improvements thereof". The term "composition of matter" relates to chemical compounds and may include mixtures of ingredients as well as new compounds.

In order for an invention to be patentable, it must be new as defined in the patent law: if the invention has been described in a printed publication or has been in public use or on sale for more than one year before the date of filing an application for a patent, a patent cannot be obtained.

An inventor can apply for a patent for the same invention in more than one country. Several patenting organizations such as the European Patent Office (EP) and the WIPO, World Intellectual Property Organization, (WO) publish patent applications. These published applications can provide information on an invention before it appears in a U.S. patent.

The patent system is designed to promote the dissemination of new technologies by publishing full details of new inventions. Chemistry, engineering, and medicine are some of the only academic fields to have an industry that is actively engaged in novel research. The bulk of publication by industrial scientists appears exclusively in the patent literature.

Patent documents are therefore an important source of information for all researchers; they often give full details of methods and of preparation of compounds, and much of the scientific information in patents is never published elsewhere.


What are the Requirements for Obtaining a Patent?

To be patentable, an invention must meet three basic criteria.

  1. It must be novel.
  2. It must be useful.
  3. It must be nonobvious.

In order to be protected in a country, the invention must be patented with that country's patent authority or with a patent authority acknowledged by that country. For example, if a patent is filed with the U.S. Patent and Trademark Office, it does not protect the invention in Japan or in Europe.

WARNING If you are interested in patenting your invention and wish to run a patentability search, please consult a professional patent searcher. If you are affiliated with the University of Pennsylvania, please contact Penn's Center for Technology Transfer

Patent Information from the Derwent Innovations Index (DII)

The Derwent Innovations Index (DII), as a part of the Web of Science Database, searches more than 14 million patent records from 40 worldwide patent-issuing authorities. These include the US Patent and Trademark Office, European Patent Office, PCT (WO) applications and the Japanese Patent Office. Searches retrieve records from 1963 to the present, but coverage varies from one patent authority to another. Many of the records do link to full-text, PDF images of the patent that can be saved or printed in their entirety.

Screenshot of the Derwent Innovations Index (DII) basic search page

Derwent, like Chemical Abstracts, rewrites the abstracts of patents to make it more apparent whether or not a particular patent would be applicable to your work. In addition, the Derwent record cites patents and other literature used by both the inventor and the patent investigator in the preparation and approval of the patent.

Patent Information in Chemical Abstracts/SciFinder Scholar

Chemical Abstracts is a the best source of chemical patent information. CA indexes patents from 150 countries in all areas of chemical science. However, since CA is giving us a large discount on SciFinder Scholar, our license prohibits the use of SciFinder for patentability searching (searching with the purpose of determining whether or not an invention is patentable).


You can restrict Chemical Abstracts searches by document type (e.g. to retrieve only patents) In SciFinder Scholar, do the search then click on the REFINE References button and choose Document Type, then Patents. If you want to limit your search from the outset, click on the Additional Options and limit by document type.

CAS Patent Coverage

Screenshot of Chemical Abstracts/SciFinder Scholar

Print Indexes 

In printed CA, a reference to a patent document is indicated by a capital 'P' in front of the abstract number, for example (from the General Subject index to vol. 123):

NMR online viscometer for liqs. or polymer melts, P66499j

The corresponding reference looks like this:

123: 66499j NMR online viscometer for liquids and polymer melts. Tanzer, Christian I. (Auburn International, Inc.) PCT Int. Appl. WO 95 08,777 (Cl. G01R33/44), 30 March 1995, U.S. Appl. 125,911, 23 Sep 1993.

The issuing country/organization number is listed (WO 95 08 777); the earliest filing date worldwide in listed.(for US application number 125,911); and the International Patent Classification code, a subject code for the patent, is provided (Cl. G01R33/44)

Searching for Patent Equivalents

The patent family includes equivalent patents published by other patent-granting authorities, and this information appears at the top of the reference, directly beneath the citation information. When you retrieve a patent written in a language that you do not read, it is very helpful to see if an equivalent patent has been published by a country whose language you do read.

Explanation of Patent Families

The Derwent Innovations Index has patent family information available for all patents included in its database. This information appears near the top of the full record for the patent. It gives links to the full text of all patents that Derwent supplies. You can view also view the patent family for every patent included in SciFinder Scholar.

In addition, the printed Patent Index to CA allows you to search for equivalent patents (patents for the same invention, granted by other countries or patenting agencies). This is useful since Chemical Abstracts only reports the earliest publication of patent information if patents have been sought from several organizations. (This is typically NOT the US Patent, since the US only publishes granted patents while other countries/organizations publish applications)

To search for these 'equivalent' patents:

  • Search the Patent indexes dated 1-3 years after the original application.
  • Search for the patent information which you have (country and number)

    An Example:

    • EP 142271 issued in 1985
    • Look for EP 142271 in the indexes for 1985-89
    • If a patent from another country issued within that time period you will see that patent number listed under the EP number
                      EP 142271
                         JP 60/090887
                         US 4543137

Derwent Innovations Index (DDI)


Search Derwent Innovations Index (DII) (

Derwent's Classification System (

Derwent Coding and Classification Look-up (

Derwent Patent Assignee Codes Look-up (

American / British Dictionary (
Both American and British spelling is found within the Derwent database. It is important to take this into account when searching in the Topic and Title fields. If in doubt as to which spelling to use, search for both options (for example, polymerized OR polymerised; vapor OR vapour)

Derwent Standard Abbreviations (

DII Manual ( format)

United States Patent and Trademark Office(USPTO)

The United States Patent and Trademark Office, The USPTO has the full page images of every patent they issued. These are presented in TIFF format, and you must print them a single page at a time.

Search  U.S. Patent Search ( 

Search the public Patent Application Information Retrieval (PAIR) system for information on the status of issued or published appliactions. You can search by patent, application, or publication number.

U.S. Patent Manual of Classification ( A hierarchical list of classes and subclasses by number.

Overview of the Classification System (PDF) (

Patent Classification FAQs (

U.S. Patent Classification Index ( 
An alphabetical list of terms cross referenced to the specific classes and subclasses used to categorize patents.

Note: Browsing is more effective than searching 
Index to the U.S. Patent Classification (Print)
Van Pelt Library Reference Stacks
T223 .F411

Patent Images Plug-in Information - Contains a link to download the TIFF Viewer ( required to view images

Official Gazette of the United States Patent and Trademark Office - Patents
A numerical listing of the patents granted that week. Only contains one drawing and one representative claim. Published weekly.

  • Past 52 weeks available online (
  • 1995 - present Official Gazette Search (
  • 1993-1997 Van Pelt Library Microfiche U.S.Doc C 21.5
  • 1975-1986 LIBRA T222 .A23
  • 1872-1970 (Official Gazette of the United States Patent Office) LIBRA T222 .A


USPTO Glossary (

Inventor Resources (

Esp@cenet,, gives full-text, pdf images of European, World/PCT, US, and Japanese patents. In addition, they cover some of the patent authorities of individual, European countries. The date ranges available for each authority vary; see their help file for database coverage.


esp@cenet Help Files (

PCT Country Codes (PDF) (

International Patent Classification Manual (

European Patent Classification (ECLA) Search(

International Patent Classification Code (IPC) - Version 8

IPC Version 8 Catchword Index - An alphabetical list of subject matter headings that provide the corresponding IPC subclass and subgroup.

esp@cenet Assistant - tutorial (requires Flash)

PCT (Patent Cooperation Treaty) Gazette Archives (

Weekly issues of the PCT Gazette (from April 4, 1998 up to 2006, and including all Special Issues) as produced in paper format are published in PDF. The PCT Database ( contains the first page data (bibliographic data, abstract and drawing) of published PCT applications.

The PatentScope Search Service replaced the PCT Gazette and allows you to search over 1 million published PCT international patent applications.


Patent Information on the Internet

Click here for links to further sites providing Patent Information.

Information on Patent Classification Codes

How to obtain Patent Documents

Derwent Innovations Index, indexes more than 14 million patent records from 40 worldwide patent-issuing authorities.

The Lens ( is a free service that searches the full text of granted patents from the United States, Europe, and Australia, as well as published US, WIPO/PCT, and Australian patent applications.

Free Library of Philadelphia, 1901 Vine Street, Philadelphia, PA 19103-1189. Tel: 215 686-5331. Open Mon-Wed 9-9, Thurs-Fri 9-6, Sat. 9-5. The Free Library of Philadelphia has a set of U.S patents on microfilm from 1964 to date, in the Government Publications Department on the first floor. Reader/printer facilities are available: the cost of printing is 15 cents per page.

Interlibrary Loan The Interlibrary Loan department can obtain copies of patent documents from any country. Request them in the same way as for journals, using the electronic form on the library's home page. When requesting a patent on ILL, it is important to supply the patent number, including the country code, and the date on which the application was made or patent granted.

Fun with Patents

The following are some amusing patent sites.

Crazy patents

Business Insider's funniest patents 

Patents Myth's 

In 2004, the Ig Nobel Prize in Engineering was awarded to the man who patented the comb-over.

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