What is diazonaphthoquinone (DNQ)?
The photoactive chemistry behind UV CtCP plates and positive photoresists.
Diazonaphthoquinone (DNQ) is a family of photosensitive compounds used in offset printing plates and electronic photoresists. Learn how DNQ works, where it is used, and which Orion grades supply each step of the value chain.
DNQ in one paragraph
Diazonaphthoquinone derivatives are organic photosensitisers that change solubility when exposed to ultraviolet light. In offset printing, DNQ-based coatings on aluminium substrates form the image layer of UV computer-to-conventional-plate (CtCP) systems. In electronics, DNQ esters blended with novolac resins are the photoactive component of positive photoresists used to pattern circuits.
Orion manufactures the sodium salt intermediate (CAS 64173-96-2), the esterified one-pack resin (CAS 3770-97-6), and a ready-to-use developer-free CtCP coating — covering the full DNQ value chain from building block to finished plate chemistry.
How DNQ photosensitivity works
DNQ compounds undergo a Wolff rearrangement on UV exposure, converting diazo ketones into ketenes that react with trace water to form indene carboxylic acids. The exposed areas become alkali-soluble (positive mode) or remain insoluble depending on formulation — CtCP plate coatings typically operate in negative-working mode where exposed areas stay on the plate.
- UV CtCP plates: imaged at 360–375 nm on laser plate setters
- Positive photoresists: DNQ-novolac systems for microelectronic patterning
- Spectral sensitivity tuned by esterification and resin choice
Orion DNQ grades mapped to the value chain
Buyers typically enter the DNQ supply chain at one of three points: the sodium salt for in-house synthesis, the ready ester for coating formulation, or the finished CtCP coating for direct plate production.
- Orion Freedom 2-1-4 — water-soluble sodium salt (CAS 64173-96-2)
- Freedom Plus 1413 — DNQ-cresol one-pack ester (CAS 3770-97-6)
- 2-1-4 Diazo Building Block — synthesis intermediate with COA
- Orion Next CtCP — developer-free ready-to-coat plate system
Qualifying an Indian DNQ supplier
Procurement teams should request a certificate of analysis (COA) per batch, MSDS/TDS documentation, and trial quantities before committing to production volumes. Orion supplies all four with 98% minimum assay across active grades and manufactures at our works in Karad, Maharashtra.