1. Introduction

DENSON NA transparent nano pigment paste is a high-performance colorant engineered for display, optical film, and precision coating applications. This guide summarizes the quality control (QC) parameters and practical application know-how developed by Dongguan DENSON Functional Materials Co., Ltd. over years of customer support. For product details, see DENSON product center.

Fig.1 NA transparent nano pigment paste samples in glass beakers on a laboratory bench

2. Technical Features and Mechanism

NA transparent nano pigment paste is defined as a pigment dispersion in which organic/inorganic pigments are milled to a median particle size below 60 nm and stabilized by tailored polymeric dispersants, enabling high light transmittance (>90%) with minimal haze. The dispersant-anchored particle surface suppresses agglomeration and maintains shelf stability.

3. Case Study 1: Display Color Filter

A display customer reported a drop in transmittance from 92% to 87% on one batch. Investigation showed D90 had reached 180 nm (spec ≤100 nm) due to worn grinding media. Replacing 0.1 mm zirconia beads and extending milling to 4 h restored D90 to 78 nm and transmittance to 91.5%.

4. Case Study 2: Optical Film Coating

An optical film customer experienced ΔE drift from 0.3 to 0.8 across three batches. Root cause was a drop in dispersant dosage from 3.0% to 2.4%, leading to poor pigment wetting. Restoring dispersant to 3.0% plus 30 min pre-mix brought ΔE back to within 0.3.

Fig.2 Roll-to-roll optical film coating line where NA paste is applied

5. Case Study 3: Storage Stability

A customer's NA-Red paste increased in viscosity from 800 to 2400 mPa·s after one month at 40 °C. The cause was evaporative solvent loss during winter storage. Advising the customer to top up with the original solvent to ±10% viscosity and pass through a 100 µm screen restored performance.

Fig.3 Bench-top spectrophotometer used for ΔE and transmittance QC

6. Key QC Parameters and Selection Guide

Always run a small-scale compatibility trial against the customer's resin, curing agent, and solvent before scale-up. See www.densonchem.com for TDS.

7. Conclusion

Over 90% of NA paste quality issues can be diagnosed through four basic checks—particle size, color difference, viscosity, and storage stability. Customers should dilute, filter, and store the paste strictly per TDS.

8. Frequently Asked Questions

Q1: Should NA paste be re-inspected on delivery?
A: At minimum check fineness, color difference, and viscosity; optical-grade customers should also verify transmittance and haze.

Q2: Is slight stratification normal during storage?
A: Yes, a light layer is normal and should redisperse on stirring; hard sediment after stirring requires supplier contact.

Q3: Can NA paste be diluted with water?
A: NA-O is solvent/UV-borne and must not be diluted with water; only the waterborne GT series uses water dilution. Follow the TDS.

Q4: What if compatibility with epoxy resin is poor?
A: Run a gradient test at 5%/10%/20% loading; flocculation indicates resin replacement or additional wetting dispersant.

Q5: What if inter-batch ΔE exceeds 0.3?
A: Keep the sample and provide the SCL lot number; DENSON will trace raw material and process records and respond within 48 h.