How Wallace Carothers Invented Nylon
The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon.
Original patent title: “Linear polyamides and their production”
The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon. Granted to EI Du Pont de Nemours and Co in 1938 with 299 forward citations, and it is now in the public domain.
Often confused with
US 2,130,948 ("Synthetic Fiber") — also invented by Wallace Carothers for DuPont and granted the very same day, September 20, 1938. The difference: this patent (US 2,130,523, "Linear polyamides and their production") covers the linear polyamide polymer itself — the nylon material, filed in 1935 — while US 2,130,948 covers spinning that polyamide into strong, oriented textile fibers (filed 1937). This page is the foundational nylon composition patent; US 2,130,948 is its companion fiber patent.
Coverage
What does this patent actually cover?
This patent describes the chemical synthesis of high-molecular-weight linear polyamides by heating diamines with dibasic acids. By controlling the polymerization process, the inventorinventorThe person who actually conceived the invention. Listed on the patent regardless of who owns it.Read more → created long-chain molecules that could be drawn into strong, flexible fibers. This process transformed simple chemical building blocks into a material capable of replacing natural silk in textiles and industrial applications.
The gap
What does this patent NOT cover?
- Does not cover non-linear or branched polyamide structures.
- Does not cover the specific manufacturing machinery used for spinning the fibers.
- Does not cover the use of polyamides in non-fiber applications like molded plastics.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
Carothers discovered that by maintaining a precise stoichiometric balance and removing water during heating, he could force the molecules to link into long, stable chains rather than short, useless clumps.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Nylon stockings
Parachute cords
Toothbrush bristles
Fishing line
Why it matters
The bigger picture
This patent marks the birth of the synthetic fiber industry. It allowed DuPont to mass-produce nylon, which became a critical material for everything from hosiery to parachutes during World War II.
Filed
January 2, 1935
Granted
September 20, 1938
Market context
Who's building on this
Companies in this space
DuPont remains a major player in the polyamide market, but the core chemistry is now foundational knowledge used by global chemical giants like BASF and Lanxess to produce various grades of nylon for automotive and industrial parts.
Market impact
This patent effectively created the multi-billion dollar synthetic fiber market. It shifted global reliance away from natural fibers like silk and cotton toward engineered materials, permanently altering the global supply chain for clothing and industrial components.
Claim 1 — Plain English
What this patent covers
This patent describes the chemical synthesis of high-molecular-weight linear polyamides by heating diamines with dibasic acids. By controlling the polymerization process, the inventor created long-chain molecules that could be drawn into strong, flexible fibers. This process transformed simple chemical building blocks into a material capable of replacing natural silk in textiles and industrial applications.
The clever bit
Carothers discovered that by maintaining a precise stoichiometric balance and removing water during heating, he could force the molecules to link into long, stable chains rather than short, useless clumps.
What it does not cover
- Does not cover non-linear or branched polyamide structures.
- Does not cover the specific manufacturing machinery used for spinning the fibers.
- Does not cover the use of polyamides in non-fiber applications like molded plastics.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$24K – $77K
Midpoint $48K · expired or expiring · industry ×0.8
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
Concepts involved
Citations
Patent lineage
Cite this patent
Carothers, W. H. (1938). How Wallace Carothers Invented Nylon (U.S. Patent No. 2,130,523). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/2130523/nylon-polyamide-carothers
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Wallace Carothers Invented Nylon cover?
The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon.
Who owns patent US 2130523?
EI Du Pont de Nemours and Co owns this patent, granted in 1938.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 2130523 cited by?
This patent has been cited by 299 later patents that build on its ideas.
What problem does this patent solve?
This patent marks the birth of the synthetic fiber industry. It allowed DuPont to mass-produce nylon, which became a critical material for everything from hosiery to parachutes during World War II.
What does this patent NOT cover?
Does not cover non-linear or branched polyamide structures.
Same assignee
More from EI Du Pont de Nemours and Co
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