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CHE 432: Principles of Chemical Engineering Design

Library and internet resources for CHE 432 assignments.


Patents are a grant from a government extending certain rights to an inventor in exchange for the inventor making a public disclosoure of his/her invention.   In the U.S., a patent grants the inventor the right to exclude others in the making, using or selling of the invention for 20 years from date of filing.   The U.S. grants patents in 3 major areas:

  • utility (electrical, chemical, mechanical and also, controversially, business procedures, genetics, and software programs)
  • design (for the way an item looks - this type of patent only last for 14 years from date of issue)
  • plant (for asexually reproduced plants)

Much of the information in patents (~70-80%) never shows up in any other place.

A patent consists of 4 parts:

  • Front page (sometimes called the Front Matter)
    Lists the basic information: inventor, title, date, patent numbers, field of search, patent examiner, attorney of record and a short, usually one paragraph, abstract.

  • Drawings
    Usually line drawings of the invention; in most chemical patents, there are no line drawings, however, structure diagrams appear throughout the Description.

  • Description
    More details about what the invention is.

  • Claims
    Literally, what the inventor says is his/her unique discovery.  The claims are the primary part of the patent -  they detail what the patent covers.  The claims are the determining factor in a patent infringement case. 

Searching Techniques

There are many databases that cover patents, however, the primary free-we" patent databases are:

    Contains U.S. patents only.  The granted patents database (PatFT) is up-dated every Tuesday morning; keyword searching is available for 1976 to the present; only patent number and patent classification searching is available prior to 1976.   The application database (AppFT) is up-dated every Thursday morning; this database started on March 15, 2001 and applications prior to 2001 are not accessible; also, some applications are not put in the database until 18 months after the application is filed.  
  • Espacenet  
    Contains patents from approximately 90 countries but coverage is uneven.  U.S. patents are covered back to 1920 but not all are in full text. IPC and EP classification searching only.  Patents less than 50 pages may be printed all at once, however, patents over 50 pages must be displayed/printed one page at a time.  


Patents are a mix of technology and the law; the terminology used in these documents is unique and not user-friendly.   Add in the tendency for generic titles (ex. "Composition of Matter and Process of Making Same") as well as inconsistent description and the result is that keyword searching is very ineffective.   Professional patent searchers get around the terminology problem by searching by patent classification either in addition to, or instead of, keyword searching.   Chemical compounds need to be searched by structure, which can be done within the SciFinder database. 

  1. Prior Art Searches for Mechanical and Electrical Inventions
    See the detailed instructions on the separate Patents library guide.
  2. Prior Art searches for Chemicals:
    • Go to SciFinder, click on the "Chemical Structure" option under "Substances" in the left-hand column.  Search for the exact structure (if this is a known compound, searching by it's name - aka "substance identifier" may be easier)
    • If no compound with the exact structure is found, try searching for:
      • Substructures, in which you do a structure search but leave open positions instead of specifying substituents, and
      • Markush search option, which will search for markush structures that sometimes appear in patents.  
    • Once you get the results list, use the "Refine by Document Type" feature in the left-hand column to limit the results just to patent references.

Patent Information for Pharmaceuticals

To find FDA information about pharmaceuticals, see the FDA Orange Book.  The orange book includes prescription drugs, over-the-counter (OTC) drugs and discontinued drugs; the database may be searched by:

  • Active ingredient (ex. fluoxetine hydrofluoride),
  • Propietary name (the tradename, Prozac), or ingredient if generics are permitted (fluoxetine hydrochloride))
  • Patent number
  • Applicant Holder (usually the drug company, ex. Lilly)

The data included in the Orange Book:

  • FDA Approval Date
  • U.S. Patent number for the synthesis/manufacturing process
  • Patent expiration date

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Need More Help?

Having trouble with any of the resources on this guide? 

Contact your librarians with related expertise, OR use the ASU Library's "Ask a Librarian" service.

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