Trade secrets vs patents for process technology

1. Core idea and who it's for#

A patent is a bargain: you publish exactly how the invention works, and in return you get about 20 years of exclusivity from filing. A trade secret makes the opposite bet. You publish nothing, and you are protected for as long as the secret stays secret, which could be forever, or could end tomorrow if someone independently develops it, reverseengineers it, or a former employee leaks it.

For process technology , the trade-off is real and often favours secrecy. Process technology covers how you make something: a synthesis route, a deposition recipe, a fermentation protocol, a calibration method, a yield-improving trick. The reason is that a process used inside your own factory is hard for others to observe, and infringement of a process patent is hard to detect and prove.

The basic test for each invention is whether it can be kept secret once you commercialise it.

• The product reveals it if you can buy the product and analyse it to find the invention: a composition, a device structure, a sequence. In that case, patent it or lose it.
• The invention stays hidden in your process, your parameters, your software running on your own servers, or your quality-control methods. In that case, a trade secret is a real option, often a better one, provided you actually run a secrecy programme.

Spinouts have two extra complications:

• University research is usually published . Anything in a paper, thesis or talk is no longer secret, so trade-secret protection only covers what the company develops privately after spinout, or what was never disclosed.
• Investors find patents easier to value and diligence. A strategy built on secrecy has to be documented well enough that it survives due diligence.

Who this is for: founders in materials, chemicals, semiconductors, biomanufacturing, batteries, energy and advanced manufacturing, where process know-how is often worth as much as the product.

2. Evidence: how the law treats each choice#

What a trade secret needs, and how it dies. Trade-secret protection lasts indefinitely, but only while the information stays secret. That makes it suitable for inventions not revealed by selling the product, typically recipes, manufacturing processes and manufacturing equipment. Losing secrecy destroys it, and so does independent development by someone else (Harness IP). Nearly every regime also requires the holder to show that it took reasonable measures to keep the information secret. India's draft bill uses the same test (Bar & Bench).

The risk that someone else patents your secret, and the US safety net. If a competitor later develops your process on its own and patents it, your secret use doesn't stop the patent, and you could be sued. The America Invents Act widened the prior commercial use defence in 35 U.S.C. 273 to cover any process, or any machine, manufacture or composition used in a manufacturing or commercial process (National Law Review). It has strict limits:

• You must have used the invention commercially in the US, in good faith, at least one year before the patentee's filing date or qualifying disclosure.
• You must prove it by clear and convincing evidence .
• The defence covers only your prior use. It is not a general licence, and it doesn't invalidate the patent (Harness IP; Post-Grant Proceedings).
• Use only outside the US doesn't count (ACC).
• One commentary notes the defence has rarely been tested all the way through trial and appeal (IAM).

In short, keep dated, detailed records of when commercial use started. The defence is a backstop, not a strategy.

Enforcement differs a lot by country.

• US: federal civil claims under the Defend Trade Secrets Act 2016, plus state laws, most based on the Uniform Trade Secrets Act.
• UK: the Trade Secrets (Enforcement, etc.) Regulations 2018, which implemented the EU directive, alongside the common-law action for breach of confidence.
• India: no dedicated statute. Protection rests on contract, equity and breach of confidence (Cyril Amarchand Mangaldas). The Law Commission proposed a Protection of Trade Secrets Bill in its 289th Report of March 2024, but as of mid-2026 it had not been enacted (Intepat).

Process patents are hard to enforce, but not impossible. Detecting that a competitor uses your process inside their plant is the main difficulty. Some laws help. In the US, importing a product made by a patented process is infringement. Several countries,

including India under section 104A of the Patents Act, shift the burden of proof to the defendant in process-patent cases in some situations. Even so, if you can't detect infringement, a published patent mostly teaches competitors.

3. Method: decide invention by invention, then run a real secrecy programme#

Step 1. List the inventions as they come up. Hold a short IP review every quarter. Ask the engineering team what they figured out that a competitor would want, and record each item.

Step 2. Score each invention on five questions.

The common result for a deeptech process company is to patent the product and the core inventive concept , which is what's visible, and keep the parameters, recipes, tuning and know-how secret, which is what makes it work at yield. Patents filed at a broader level can also avoid disclosing your best mode in full detail. Note that the US still requires best mode to be disclosed, though failing to do so is no longer grounds for invalidity, so get advice.

Step 3. Run a trade-secret programme , because without one you may have no trade secret at all.

• Identify: keep a register of each secret, with what it is, who has access and where it is held.
• Restrict: give access on a need-to-know basis, with access controls on repositories and lab-notebook systems, and split critical recipes so no single person outside the core team holds all of it.
• Contract: have confidentiality and IP-assignment agreements with every employee, contractor and adviser. Use NDAs with partners and customers before you disclose anything, and include clauses on returning or destroying material.
• Mark and train: label confidential documents, and train staff on what they can and can't say at conferences and in papers.
• Departures: hold exit interviews, recover devices, and remind leavers of their obligations.
• Document: keep dated records of development and commercial use. These support a US prior-user defence and any misappropriation claim.

Step 4. Manage publication. Agree with academic co-founders and the university which process details stay out of papers and theses (2.13, 2.14). Publish the science, not the recipe.

Step 5. Revisit the decision. If a competitor gets close, or you plan to license the process, consider filing. Licensing a trade secret is possible, but harder to police.

Worked example (illustrative)#

A solid-state battery startup has three process inventions:

1. A new electrolyte composition. It can be found by analysing the cells, so it is patented . A provisional was filed before the founder's conference talk (2.05).
2. A sintering profile (the temperature ramp, atmosphere and hold times) that raises density from 92% to 98%. This can't be seen in the finished cell, and competitors' furnace settings can't be observed, so it is kept as a trade secret . Only four people know the full profile, the parameters are stored in an access-controlled manufacturing execution system, and all employees have signed confidentiality and assignment agreements.
3. An in-line defect detection method using a camera and a model. The method is patented at a broad level as a novel measurement technique. The trained model and its training data are kept secret (2.17).

In the data room, the company shows investors the patent family and a trade-secret register, which lists each secret, its owner and the protections around it but not the content, together with the employee agreements. The lead investor's IP counsel reviews the full process documents under a clean-team NDA. Diligence closes with no gaps.

4. India / US / UK differences#

India in practice. Contracts are the main protection, because there is no trade-secret statute. Make sure every employee, contractor, intern and collaborator signs confidentiality and IP-assignment terms before they get access. Keep records good enough to prove both the confidentiality and the breach.

US in practice. Use the DTSA's whistleblower-immunity notice in employee agreements. If you leave it out, you may lose the right to exemplary damages and attorney fees against that employee.

UK in practice. Mark confidential information clearly, and record the reasonable steps you take to protect it. The 2018 Regulations require them.

5. Scripts, mistakes, related playbooks and sources#

Scripts#

To your patent attorney:

"For each of these three inventions, tell us what claims we could get and how we'd detect infringement. For the sintering profile, how would we prove a competitor used it? If we can't, we'd rather keep it secret. What would we need to disclose in the composition patent, and can we avoid disclosing the process parameters?"

To an academic co-founder before a paper:

"The paper should show the material and the mechanism. The exact process window and the furnace profile are company trade secrets. Can we describe the method in general terms in the paper, with the specific conditions available only under a materials transfer agreement?"

To investors in diligence:

"Our IP is a patent family on the composition and the measurement method, plus documented trade secrets for the manufacturing process. Here is the register, the access controls and the employee agreements. Your counsel can review the process documents under a clean-team NDA."

Common mistakes#

1. A "trade secret" with no secrecy measures. No register, no access control and no NDAs means there is no legal protection.
2. Keeping secret something the product reveals. A competitor buys the product, analyses it, and patents the improvement.
3. Publishing the recipe in a thesis, paper or conference poster.
4. Relying on non-competes in India. They are generally unenforceable. Use confidentiality instead.
5. No dated records of commercial use, so the US prior-user defence becomes impossible to prove.
6. Patenting process details you can't police. That teaches competitors how to do it.

Related playbooks#

• 2.04 Patent or publish first
• 2.05 Provisionals and the PCT
• 2.13 Students and postdocs as founders
• 2.17 Rights to research data
• 2.19 Patent landscape mapping
• 2.20 IP budget at pre-seed
• 14.10 The seed data room

Sources#

• Prior user defence protects trade-secret owners, Harness IP
• America Invents Act: prior user commercial rights, National Law Review
• Prior user rights: the prior commercial use defence, Post-Grant Proceedings
• What happens if a competitor patents my trade secret?, Association of Corporate Counsel
• Prior user rights defence to patent infringement, IAM
• The Protection of Trade Secrets Bill 2024, Intepat
• The 22nd Law Commission report on trade secrets, Cyril Amarchand Mangaldas
• Safeguarding secrets: the Law Commission's push, Bar & Bench

The worked example is illustrative. This playbook is not legal advice: whether to patent or keep a secret depends on the facts, so decide each invention with a patent attorney. Last checked November 2026.