The insulating colorant market is being driven by new-energy electrification, and procurement decisions increasingly balance cost, compliance, and sustainability. This article quantifies three cost-reduction cases and summarizes the regulatory and sustainability trends shaping insulating colorant selection. DENSON insulating colorants are supplied by Dongguan DENSON Functional Materials Co., Ltd.

1. Introduction

800 V vehicle platforms, charging infrastructure, cast-resin transformers, and photovoltaic and energy-storage inverters are the main demand drivers for colored insulation. Ready-to-use, high-concentration colorants reduce in-house grinding, lower dosage, and support low-VOC compliance. The three cases below document measured cost and quality outcomes; see the DENSON EP colorant series.

2. Technical Features and Mechanism

An insulating colorant is a concentrated dispersion of dielectric-grade pigments in a carrier resin matched to the host compound (epoxy, silicone, or polyurethane). Its value is determined by pigment loading, tinting strength, fineness, and compatibility: a higher, well-dispersed pigment loading reduces dosage and therefore the amount of foreign carrier introduced into the insulation.

3. Case Study 1: Ready-to-Use Colorant Replaces In-House Grinding

A motor maker replaced in-house pigment grinding (about 8 h per batch, fineness 10–15 μm, material loss about 8%) with a finished colorant at fineness ≤5 μm and loss ≤1%. Grinding labor was eliminated and the total coloration cost index fell from 100 to 78.

Fig.1 Vacuum epoxy casting plant serving the dry-type transformer segment

4. Case Study 2: High-Concentration Colorant Reduces Dosage

A power-module maker switched to a high-tinting-strength colorant (tinting strength about 180% of standard). Dosage fell from 3% to 1.5%, the defect rate fell from 2.5% to 0.6%, dielectric-strength retention stayed at ≥90%, and the per-module colorant cost index fell from 100 to 71.

Fig.2 DC charging-pile assembly line, a fast-growing colorant end market

5. Case Study 3: Low-VOC Formulation for Compliance

A coating line converted from a solvent-borne colorant to a solvent-free/high-solids grade, reducing VOC content from about 350 to ≤50 g/L and meeting RoHS and REACH requirements; recyclable steel drums further reduced packaging waste.

Fig.3 Colorant production workshop with multi-stage reactor trains

6. Key Selection Parameters and Recommendations

Recommendation: procure by total applied cost rather than unit price, and require VOC and restricted-substance documentation. More grades are listed on the DENSON website.

7. Conclusion

Ready-to-use and high-concentration insulating colorants cut total coloration cost by roughly 20–30% while maintaining dielectric-strength retention at ≥90%. Low-VOC, RoHS/REACH-compliant formulations and recyclable packaging are now baseline procurement requirements rather than differentiators.

8. FAQ

Q1: What is driving growth in the insulating colorant market?
Electrification is the main driver: 800 V vehicle platforms and hairpin motors, charging infrastructure, cast-resin transformers, and PV and energy-storage inverters all require color-coded, dielectric-grade insulation, with the new-energy segments showing the highest growth.

Q2: How much can a finished colorant save compared with in-house grinding?
In the documented case, replacing in-house grinding eliminated about 8 hours of batch labor, reduced material loss from about 8% to ≤1%, and lowered the total coloration cost index from 100 to 78, while improving fineness from 10–15 μm to ≤5 μm.

Q3: Why does a high-concentration colorant reduce cost?
A colorant with tinting strength about 180% of standard is used at roughly half the dosage (1.5% instead of 3%), introducing less foreign carrier, lowering the defect rate from 2.5% to 0.6%, and cutting the per-module colorant cost index from 100 to 71.

Q4: What VOC limit applies to industrial colorants in China?
GB 30981 sets limits for harmful substances in industrial protective coatings; solvent-free or high-solids colorants can reach VOC content ≤50 g/L, compared with about 350 g/L for conventional solvent-borne products, and should also meet RoHS and REACH requirements.

Q5: Which specification items should be included in a procurement standard?
Include non-volatile content (≥40%), dosage (1–3%), fineness (≤5 μm), tinting strength (100 ± 5%), VOC content, soluble heavy metals, dielectric-strength retention (≥90%), and shelf life (≥12 months), supported by GB/T 1725, GB/T 1724, GB/T 5211.19, GB 30981, and GB/T 1408 reports.