# How DuPont Invented Neoprene Synthetic Rubber

> A 1934 patent describing the chemical process to turn chlorobutadiene into a durable, oil-resistant synthetic rubber known as Neoprene.

- **Patent:** US 1967861
- **Original title:** Process of polymerizing chlorobutadiene and resulting product
- **Owner:** EI Du Pont de Nemours and Co
- **Granted:** 1934
- **Status:** Public domain (expired)
- **Times cited:** 7
- **Field:** materials, chemical_manufacturing, automotive

## What it does

The patent outlines a chemical process for polymerizing chlorobutadiene, a liquid monomer, into a solid, rubber-like material. By controlling the reaction conditions, the process creates a synthetic elastomer that mimics the properties of natural rubber but offers superior resistance to oils, heat, and weathering. This invention allowed for the mass production of a stable, elastic substance that could be molded or shaped for industrial use.

## What it does NOT cover

- Does not cover the synthesis of natural rubber derived from latex trees.
- Does not cover other types of synthetic rubbers like styrene-butadiene (SBR).
- Does not cover the specific vulcanization additives used in finished consumer goods.

## The clever bit

The invention successfully stabilized a highly reactive chemical (chlorobutadiene) that previously tended to spontaneously turn into a useless, hard, and brittle resin, turning it into a useful, elastic polymer instead.

## Real-world examples

1. Wetsuits for surfing and diving
2. Automotive fan belts and hoses
3. Protective industrial gloves
4. Laptop sleeves and cases

## Why it matters

This patent marks the birth of the synthetic rubber industry. It provided a critical alternative to natural rubber, which became a strategic necessity during World War II when supply chains for natural latex were severely disrupted.

## Frequently asked questions

### What does How DuPont Invented Neoprene Synthetic Rubber cover?

A 1934 patent describing the chemical process to turn chlorobutadiene into a durable, oil-resistant synthetic rubber known as Neoprene.

### Who owns patent US 1967861?

EI Du Pont de Nemours and Co owns this patent, granted in 1934.

### 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 1967861 cited by?

This patent has been cited by 7 later patents that build on its ideas.

### What problem does this patent solve?

This patent marks the birth of the synthetic rubber industry. It provided a critical alternative to natural rubber, which became a strategic necessity during World War II when supply chains for natural latex were severely disrupted.

### What does this patent NOT cover?

Does not cover the synthesis of natural rubber derived from latex trees.

**Full plain-English explainer:** https://patentbrief.org/patent/us/1967861/neoprene-synthetic-rubber

**Original patent:** https://patents.google.com/patent/US1967861

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [How Spandex Elastic Fibers Are Chemically Engineered](https://patentbrief.org/patent/us/2929804/spandex-lycra-elastic-fiber) — DuPont's 1960 patent for a stretchy, durable synthetic fiber made from segmented polymers, which became the foundation for modern Spandex.
- [How Charles Goodyear Invented Modern Vulcanized Rubber](https://patentbrief.org/patent/us/3633/vulcanized-rubber-goodyear) — Charles Goodyear's 1844 patent describes the process of heating raw rubber with sulfur to create a durable, weather-resistant material.
- [The Discovery of Teflon](https://patentbrief.org/patent/us/2230654/teflon-ptfe-polymer) — This 1941 patent describes the creation of polytetrafluoroethylene, a slippery, heat-resistant plastic discovered by accident that became known as Teflon.
- [How Wallace Carothers Invented Nylon](https://patentbrief.org/patent/us/2130523/nylon-polyamide-carothers) — The foundational 1935 patent for synthetic linear polyamides, the chemical process that created the material we now call nylon.
- [How Leo Baekeland Invented Bakelite, the First Synthetic Plastic](https://patentbrief.org/patent/us/942699/bakelite-synthetic-plastic) — A 1909 patent for creating a durable, heat-resistant material by reacting phenol and formaldehyde, marking the birth of the modern plastics industry.