Analyzing the Scope and Claims of United States Patent 4,789,724: A Comprehensive Guide
Introduction
United States Patent 4,789,724, titled "Preparation of Anhydride Copolymers," is a significant patent in the field of polymer chemistry, particularly in the synthesis of anhydride copolymers. This patent, assigned to Abraham J. Domb and Robert S. Langer, was granted on December 6, 1988. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background and Context
The invention of anhydride copolymers is crucial in the development of biodegradable materials, especially for medical applications such as drug delivery systems and tissue engineering. The patent addresses the need for pure and well-defined anhydride copolymers, which were previously challenging to produce due to the presence of impurities and the lack of control over the polymerization process.
Scope of the Patent
Overview of the Invention
The patent describes a method for preparing very pure anhydride copolymers composed of aromatic and aliphatic diacids. These copolymers are synthesized through a controlled polymerization process that ensures the absence of impurities and allows for precise control over the molecular structure of the resulting polymers[4].
Key Components
- Monomers: The patent specifies the use of aromatic and aliphatic diacids as monomers. These diacids are polymerized to form the anhydride copolymers.
- Polymerization Process: The method involves a two-step process where the diacids are first converted into their corresponding acid chlorides, which are then polymerized to form the anhydride copolymers.
- Purification: The patent emphasizes the importance of purification steps to ensure the removal of impurities, resulting in highly pure anhydride copolymers.
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention:
- Claim 1: This claim describes the method for preparing anhydride copolymers by polymerizing a mixture of aromatic and aliphatic diacids.
- Claim 2: This claim specifies the use of acid chlorides derived from the diacids in the polymerization process.
- Claim 3: This claim details the purification steps necessary to obtain highly pure anhydride copolymers[4].
Dependent Claims
The dependent claims further elaborate on the independent claims by specifying various aspects of the invention, such as the types of diacids used, the conditions for polymerization, and the properties of the resulting copolymers.
Patent Landscape
Related Patents
The patent landscape surrounding U.S. Patent 4,789,724 includes several related patents that build upon or are closely related to this invention:
- U.S. Patent 4,857,311: This patent, also by Domb and Langer, describes polyanhydrides with improved hydrolytic degradation properties, which is a subsequent development in the field of biodegradable polymers[4].
- U.S. Patent 4,888,176: This patent discusses the preparation of high molecular weight polyanhydrides for controlled drug delivery, further expanding the applications of anhydride copolymers[4].
International Patents
Similar inventions and related research have been patented in other countries, reflecting the global interest in biodegradable polymers:
- European Patent EP0605536A4: This patent describes fatty acid terminated polyanhydrides, another type of biodegradable polymer used in drug delivery systems[4].
Search and Analysis Tools
For researchers and inventors looking to navigate the patent landscape related to U.S. Patent 4,789,724, several tools are available:
- USPTO Patent Public Search: This tool allows users to search existing patents and published patent applications, including those related to anhydride copolymers[1].
- Global Dossier: This service provides access to the file histories of related applications from participating IP Offices, helping users to identify similar patents and their status[1].
- Patent and Trademark Resource Centers (PTRCs): These centers offer local search resources and training in patent search techniques, which can be invaluable for detailed analysis[1].
Economic and Research Implications
The Patent Claims Research Dataset by the USPTO provides insights into the economic and research implications of patents like U.S. Patent 4,789,724. This dataset includes detailed information on claims from U.S. patents and patent applications, which can be used to analyze trends and the scope of patent protection in the field of polymer chemistry[3].
Applications and Impact
The anhydride copolymers described in U.S. Patent 4,789,724 have significant applications in medical and pharmaceutical fields:
- Biodegradable Drug Delivery Systems: These copolymers can be used to create controlled release matrices for drugs, ensuring sustained and targeted delivery.
- Tissue Engineering: The biodegradable nature of these polymers makes them suitable for use in tissue engineering applications, where they can serve as scaffolds for tissue growth.
Key Takeaways
- Method of Preparation: The patent describes a method for preparing pure anhydride copolymers through a controlled polymerization process.
- Purification Steps: Emphasis is placed on the purification steps to ensure the removal of impurities.
- Related Patents: The patent is part of a broader landscape that includes other patents on biodegradable polymers.
- Applications: The anhydride copolymers have significant applications in drug delivery and tissue engineering.
FAQs
Q: What is the main invention described in U.S. Patent 4,789,724?
A: The main invention is a method for preparing very pure anhydride copolymers composed of aromatic and aliphatic diacids.
Q: What are the key components of the anhydride copolymers described in the patent?
A: The key components are the diacids (aromatic and aliphatic) and their corresponding acid chlorides used in the polymerization process.
Q: How do the purification steps contribute to the invention?
A: The purification steps ensure the removal of impurities, resulting in highly pure anhydride copolymers.
Q: What are some of the applications of the anhydride copolymers described in the patent?
A: The copolymers are used in biodegradable drug delivery systems and tissue engineering.
Q: How can one search for related patents to U.S. Patent 4,789,724?
A: One can use tools like the USPTO Patent Public Search, Global Dossier, and Patent and Trademark Resource Centers (PTRCs) to search for related patents.
Sources
- USPTO - Search for patents. Retrieved from https://www.uspto.gov/patents/search
- USA.gov - U.S. Patent and Trademark Office (USPTO). Retrieved from https://www.usa.gov/agencies/u-s-patent-and-trademark-office
- USPTO - Patent Claims Research Dataset. Retrieved from https://www.uspto.gov/ip-policy/economic-research/research-datasets/patent-claims-research-dataset
- Google Patents - EP0605536A4. Retrieved from https://patents.google.com/patent/EP0605536A4
