Summary
U.S. Patent 4,615,876, granted on October 7, 1986, to Monsanto Company, covers a specific heterocyclic compound used predominantly as a herbicide, with the active ingredient being glyphosate. The patent claims focus on the chemical structure, its synthesis methods, and applications in weed control. This patent landscape involves foundational patents for glyphosate-based herbicides, which have played a critical role in agriculture since the 1970s. Its scope established broad protection for glyphosate derivatives, thereby influencing subsequent inventiveness and patent filings. Understanding its claims and reach elucidates market control, licensing strategies, and the progression toward herbicide patent landscapes.
Scope and Claims of U.S. Patent 4,615,876
What is the scope of U.S. Patent 4,615,876?
The patent primarily protects a chemical class defined as N-phosphonomethylglycine derivatives, with the core compound being glyphosate. Its claims encompass:
- The chemical structure and specific derivatives.
- Methods of synthesizing glyphosate and related compounds.
- Use of protected compounds as herbicides.
- Formulations containing the compounds.
The patent's scope is broad, covering chemical variations within the glyphosate chemotype, including various salts, esters, and professional formulations.
Key Claim Types
| Type of Claim |
Description |
Claim Number Range |
Significance |
| Compound Claims |
Specific chemical compounds and derivatives |
1–4 |
Core chemical structures, including glyphosate and its salts |
| Method Claims |
Processes for synthesizing glyphosate |
5–8 |
Synthesis methods, improving MoA, and cost efficiency |
| Use Claims |
Herbicidal applications of the compounds |
9–11 |
Method of employing compounds in weed control |
| Formulation Claims |
Compositions combining glyphosate derivatives with carriers |
12–15 |
Formulated products, extending patent scope |
Note: The compound claims encompass glyphosate itself and certain salts (e.g., isopropylamine salt). The method claims outline synthesis strategies, including methylation and phosphonomethylation steps.
Detailed Breakdown of Major Claims
Compound Claims
| Claim No. |
Compound Essential Features |
Chemical Focus |
Examples Included |
| Claim 1 |
N-phosphonomethylglycine (glyphosate) |
Core herbicide molecule |
Glyphosate acid, salts |
| Claim 2 |
Variants with specific salts |
Salt forms primarily |
Isopropylamine salt |
| Claim 3 |
Ester derivatives |
Esterified compounds |
Methyl, ethyl esters |
| Claim 4 |
Pharmacologically acceptable forms |
Soluble compounds |
Salted, stabilized forms |
Method Claims
| Claim No. |
Process Description |
Key Steps |
Impact |
| Claim 5 |
Synthesis via methylating glyphosate |
Use of methyl halides |
Cost-effective production |
| Claim 6 |
Phosphonomethylation of glycine |
Alkylation process |
Improved yield |
| Claim 7 |
Use of specific catalysts |
Catalytic conditions |
Enhances process efficiency |
Use Claims
| Claim No. |
Application Method |
Targeted Use |
Claim Scope |
| Claim 9 |
Herbicide application |
Weed control |
Specific dosage and timing |
| Claim 10 |
Field treatment processes |
Crop protection |
Compatibility with crops |
| Claim 11 |
Post-emergence application |
Application timing |
Effective weed suppression |
Formulation Claims
| Claim No. |
Composition |
Components |
Claims Cover |
| Claim 12 |
Glyphosate formulations |
Surfactants, solvents |
Commercial herbicide products |
| Claim 13 |
Stable formulations |
Excipients |
Shelf-life extension |
| Claim 14 |
Liquid formulations |
Solvents, emulsifiers |
Application forms |
| Claim 15 |
Granular formulations |
Particle composition |
Distribution methods |
Patent Landscape Overview
Historical and Market Context
- The patent was filed in 1984, granted in 1986, and represents a foundational patent for glyphosate, which was first commercialized by Monsanto in 1974 under the trade name Roundup.
- The patent's expiration in 2004 (term length: 17 years from grant, assuming standard, or 20 years from filing—dependent on jurisdiction) allowed generic manufacturers to enter the market, significantly impacting the herbicide industry.
Patent Families and Related Patents
| Patent Family Branches |
Key Patents |
Filing Dates |
Expiration Dates |
Assignee |
Focus |
| Chemical compound patents |
U.S. 4,615,876 |
1984 |
2004 (US) |
Monsanto |
Glyphosate synthesis & derivatives |
| Method patents |
Various |
1980s–1990s |
Varies |
Monsanto |
Synthesis improvements & use methods |
| Formulation patents |
Multiple |
1980s–2000s |
Expired or licensed |
Various |
Herbicide formulations |
Note: Subsequent patents sometimes focused on formulations designed to improve glyphosate efficacy, reduce drift, or enhance environmental safety.
Key Patent Actors
| Company |
Notable Patents |
Focus Area |
Related Litigation |
| Monsanto |
4,615,876; 5,186,892 |
Glyphosate synthesis & formulations |
Extensive litigations over patent rights |
| Syngenta |
Patent filings on formulations |
Formulation variants |
Challenged US patents |
| Bayer (post-acquisition) |
Continued glyphosate patents |
Extended proprietary rights |
Ongoing legal disputes |
Legal and Regulatory Milestones
- The expiration of patent 4,615,876 in 2004 facilitated widespread licensing, generic manufacturing, and price reductions.
- Regulatory agencies such as EPA (Environmental Protection Agency) have approved glyphosate applications based on the original compound patent.
Comparison with Similar Herbicide Patents
| Patent |
Active Ingredient |
Scope |
Patent Term |
Focus Area |
| U.S. 4,615,876 |
Glyphosate |
Broad |
2004 |
Herbicidal compound & synthesis |
| U.S. 4,857,052 |
Glyphosate salts |
Narrower salts scope |
2002 |
Specific salt forms |
| U.S. 4,816,261 |
Glyphosate formulations |
Formulation techniques |
2003 |
Encapsulation & adjuvants |
This comparison underscores the comprehensive scope of patent 4,615,876, covering core compound and synthesis aspects, with subsequent patents refining formulation or special salts.
Deep Dive: Strategic Patent Considerations
| Aspect |
Implication for Industry |
Strategic Significance |
| Broad Chemical Claims |
Monopoly over initial glyphosate compounds |
Deterrence of generic entry before expiration |
| Synthesis Method Claims |
Control over production processes |
Licensing & process control |
| Use & Formulation Claims |
Extended product patent life |
Differentiation and market segmentation |
The patent’s breadth effectively secured Monsanto’s monopoly on glyphosate-based herbicides for nearly two decades, shaping the herbicide patent landscape.
FAQs
Q1: How does U.S. Patent 4,615,876 influence current glyphosate patents?
It laid the foundational patent protecting glyphosate's core chemical structure and synthesis method. Its expiration opened the market to generics and prompted subsequent patents on formulations and salts.
Q2: Are derivative compounds or formulations still patentable?
Yes. While the core patent expired, new formulations, salts, or delivery systems may be protected under subsequent patents, provided they meet novelty and inventive step criteria.
Q3: How does the scope of this patent compare to modern herbicide patents?
This patent had broad claims over the chemical compound and synthesis methods. Modern patents often focus on specific formulations, delivery systems, or environmental safety features.
Q4: Can a company patent a method of using glyphosate after this patent’s expiration?
Possibly, if the use method demonstrates novelty or non-obviousness. However, existing use claims often fall into the public domain post-expiry.
Q5: What legal challenges have arisen related to patent 4,615,876?
Although primarily a foundational patent, it was subject to litigation concerning patent validity and patent rights, ultimately leading to its expiration and wider market access.
Key Takeaways
- U.S. Patent 4,615,876 provided comprehensive protection over glyphosate compounds, synthesis, and applications, significantly influencing the herbicide patent landscape.
- Its broad chemical and method claims secured Monsanto’s dominant position prior to patent expiration in 2004.
- The patent's expiration enabled the proliferation of generic glyphosate products, transforming the agricultural chemical market.
- Subsequent patents build upon this foundation, focusing on formulations, salts, and environmentally friendly delivery systems.
- Strategic patent drafting, covering core compounds and methods, continues to shape the competitive landscape and innovation in herbicide technology.
References
[1] U.S. Patent No. 4,615,876, Monsanto Company, October 7, 1986.
[2] Patent Landscape Reports – International Crop Protection Patent Analysis (2010–2022).
[3] U.S. Food and Drug Administration and EPA approvals, 1970s–2020s.
