Skip to Main Content

Chemistry: Patents

Last Updated: May 17, 2022 2:04 PM

On this Page

  1. Overview
  2. How to Read a Patent
  3. Why Research Patents?
  4. Patent Search: CPC Classification Codes
  5. Patent Search: Browsing
  6. Databases 


This page will present an overview of patent law and tips for searching patents. It is an introductory overview of the subject, with videos and suggested readings. 

What is a Patent? 

A patent is a form of intellectual property. This term refers to "creations of the mind, such as inventions; literary and artistic works; designs; and symbols, names and images used in commerce." ( When a patent is granted, an inventor is given exclusive legal rights in exchange for the public disclosure of an invention. The patent permits the owner to exclude others from making, selling, using, offering for sale, or importing the claimed invention for a term of approximately 20 years. Patent terms are dependent on a number of factors; it is best to consult with an attorney for a precise determination.   

Here in the U.S., patent rights are as old as the Constitution, which authorizes Congress to "promote the progress of science and useful arts, by securing for a limited time to authors and inventors the exclusive right to their respective writings and discoveries." Patent law is codified in Title 35 of the U.S. Code

There are three types of patents: (1) utility; (2) design; and (3) plant. Patents for chemical discoveries are classified under the utility patent category. A chemical patent may be granted for:

  • a compound, which may be defined as a class of compounds or as a specific compound or group of compounds; a mixture containing two or more compounds;
  • a composition containing the compound;
  • an article made from the compound or containing the compound;
  • a process for preparing the compound, mixture, composition; or
  • a method of using the compound for a specific purpose (e.g., for curing a polymer system or for treating a medical condition.

(ACS Guide, link below) 

How do I obtain a patent? 

Statutory requirements for patentable inventions are found in Title 35 of the U.S. Code.  These requirements include factors such as utility, novelty and non-obviousness. Please know that the the patent application process is notoriously complex. For instance, it is important to be aware of the limits surrounding technology disclosure prior to filing a patent. (For a detailed explanation, please review the links referenced below.) This complexity is heightened by the practice of filing for a patent in multiple countries.

For more information:  American Chemical Society: "What Every Chemist Should Know about Patents" (4th ed.);"Who Owns my Invention"; and "Global Patent Protection"; U.S.P.T.O.: Patent BasicsA Guide to Filing a Utility PatentPursing International Patent ProtectionUniversity at Buffalo: UB Libraries Guide to Patents; Innovation Hub: Intellectual Property AssistanceCrashCourse Intellectual Property: Patents (video)

How to Read a Patent

A patent is a highly technical document. Getting to know the different sections of a patent will aid you in interpreting the document. Please review the video and definitions for an overview of a patent's structure.

How to Read a Patent

Patent number

This is the official number of the patent.  Keep in mind that both patent applications and issued patents will have a number assigned. (e.g., US 11,555,555 B2)
Title This is a clear and concise description of the patent. Note that an application and an issued patent may have different titles; this is often in response to modifications suggested by the patent examiner.
Inventors A listing of the inventors of the patent.
Assignee If the patent is owned by someone other than the listed inventors, the entity is listed here. The entity may be a corporation or a university. 
References Cited This is a listing of the references, often patents, relied upon by the assignee/inventor and/or the patent examiner. If you are doing research, it may be helpful to review some of these patents and other listed publications. 
Abstract Similar to a journal article, the abstract is a summary of the invention and its technical features. 
Drawings Review the drawings for a visual summary of the invention.

A description is meant to "describe the invention in sufficient detail to enable a skilled person to perform the method and/or produce the product disclosed in the patent. . . this section will contain details about the best method for using and/or manufacturing the invention and may include information about the materials from which the invention can be constructed, the relative amounts of different components of an invention, and so on."  (See, Tips, below) 

Claims Claims are often referred to as the "heart" of the invention. This is where the intellectual property rights (e.g., the right to sell, make, etc.) kick in. 

These tips have been adapted from Tips for Reading Patents: A Concise Introduction for Scientists and How Do I Read a Patent?

Why Research Patents?

So, what are the benefits of patent research? 

  • Expand your research beyond journal articles. 
    • Patents are a primary source of literature.
    • There are times when chemical discoveries are identified in patents first but, 
    • there are also times when your discovery has already been patented and that is equally important to know (e.g. prior art).  
  • Keep current with industries/academics in your field.
    • According to the National Academy of Inventors (NAI), the U.S. universities with the most granted utility patents include: The University of California System, Massachusetts Institute of Technology, The University of Texas System, Johns Hopkins University, and the University of Michigan. UB is a member of the NAI - seven UB inventors have been honored as NAI Fellows. 
  • Identify new opportunities and research trends.

For more information: Chemical and Engineering News column "Why We Should Care About Patents" ACS Guide "What Every Chemist Should Know about Patents" (4th ed.)

Patent Search: CPC Classification Codes

In general, a classification system is used to organize things. For example, picture how books are organized in Lockwood Library. They are labeled and shelved according to Library of Congress headings (e.g. QD22.M36 A3 1993 = From Small Organic Molecules to Large: A Century of Progress). Similarly, the Cooperative Patent Classification (CPC) system is used by both the U.S.P.T.O and the European Patent Office (E.P.O.) to organize patents. The organizations agreed to the CPC in order to further coordinate the worldwide patent system. It was implemented on January 1, 2015. Because the CPC system has been added to backfiles, this search technique may be used for patents issued prior to that date (there are, of course, some exceptions).

Think of the CPC code as a hierarchical structure, like an outline, which serves to classify patents at the most precise level based on specific characteristics and relationships. The highest level of the structure is the section field, which divides the fields of technology as follows: 

CPC Main Sections
Classification Letter Section
Y General tagging of new technological developments or of cross-sectional technologies spanning over several sections of the IPC; technical subjects covered by former USPC cross reference art collections and digests 

The next level is the class. The classes for Section C are divided into Chemistry (C01-C14); Metallurgy (C21-C30); and Combinatorial Technology (C40). Under the notes for Section C, the class description is elaborated to include pure chemistry, applied chemistry, other industries (e.g., manufacture of coke; fermentation industry), and metallurgy.  

The hierarchical structure is then further divided by subclass. For instance, Class C07 is Organic Chemistry. Under C07, there are 8 subclasses. Each subclass includes notes and cross-references.

The next step in our outline is a group. Like this: 

Image source: CPC Essentials I Part B

Explore Section C: U.S.P.T.O. CPC Classification Resource (click through the blue links on the page to dive into the groups and subgroups)

Patents are classified according to the "last place rule" - in general, this means that the patent will be assigned the most specific CPC code that describes the underlying invention. This adds an additional challenge to patent searching but there are strategies to address this issue. 

Let's search!  This video will demonstrate a patent search using CPC codes and Espacenet


Patent Search: Browsing

One of the best publications for browsing newly issued patents is the Official Gazette for Patents, which is published by the U.S.P.T.O. on Tuesdays. This link will take you directly to the homepage for the OG. 

  • The most recent 52 weekly issues are available to view online.
  • The issues may be browsed by classification (CPC) or type of patent, e.g., utility, design, and plant.
  • Specific patents may be accessed by classification or patentee name.
  • For each patent displayed, you may click the "Full Text" button in the upper left corner to retrieve the full text of the patent from the U.S.P.T.O. Full Text database. 



For patent research, it is best to start with the publicly-accessible databases. You may wish to search more than one database, as the scope of coverage in each does vary. Keep in mind that the databases contain both patent applications and issued patents; there is a difference in the legal rights granted by each. Both are useful for determining whether an invention has been previously disclosed. Please refer to UB's Innovation Hub with further questions.


Espacenet is accessible to beginners and experts and is updated daily. Scope of coverage information is updated in this link. It contains data on more than 120 million patent documents from around the world.     

Google Patents

Google Patents includes over 120 million patent publications from 100+ patent offices around the world, as well as many more technical documents and books indexed in Google Scholar and Google Books, and documents from the Prior Art Archive. 

U.S.P.T.O. Patent Full-Text and Image Database

This should be your third choice for searching as the search engine is not as powerful as Espacenet or Google Patents. Patents may be searched in the USPTO Patent Full-Text and Image Database (PatFT). The USPTO houses full text for patents issued from 1976 to the present and PDF images for all patents from 1790 to the present. The database for searching applications is available here.

Use the UB databases to dig deeper. For instance, try using SciFinder-n's Patent Pak or the Web of Science's Derwent Innovations Index. Both are highly specialized and advanced tools for your research.  Additionally, SciFinder-n permits a Markush search, which provides references "displaying the assembled structure, including patent number, location (claim number) of the assembled structure, and the G or R groups used in building the Markush structure." 

"Chemistry Lab" by canyon289 is licensed under CC BY-NC-ND 2.0