Pigment heat resistance is the ability of a pigment to keep its shade, color strength and performance after exposure to processing or service temperature. It matters in plastics, masterbatch, powder coating, baked coatings and some printing ink systems because heat can cause shade change, darkening, loss of strength, bleeding, migration or poor final appearance.
For buyers, the key point is simple: do not approve a pigment by color only. Check the actual process temperature, residence time, resin or binder system, and final performance target before selecting a grade. Fortune Chem uses heat resistance as one of the first filters when recommending pigments for plastics, pigments for coatings and pigments for printing inks.
Quick answer
For plastics and masterbatch, pigment heat resistance must be higher than the real extrusion or molding condition, including residence time and repeated heat history. For powder coating and baked coatings, it must survive curing temperature without color shift. For inks, heat resistance is usually less severe, but packaging, lamination, drying, overprint varnish and hot-fill conditions can still make heat stability important.
A TDS heat value is a starting point, not final approval. Always test the pigment in the buyer's own polymer, resin, ink vehicle, coating binder and process.
What heat resistance really means
Heat resistance is not only a maximum temperature number. A pigment can be listed as heat resistant at a certain temperature but still behave differently when the resin, time and shear change.
| Factor | Why it matters | Buyer check |
|---|---|---|
| Temperature | Higher temperature increases risk of shade change or degradation | Compare the TDS value with real barrel, bake or drying temperature. |
| Residence time | Longer exposure can be harder than a short lab test | Ask how long the pigment sees peak temperature in production. |
| Resin or binder | Pigment stability can change by PE, PP, PVC, PA, powder coating resin or ink vehicle | Test in the actual system, not only in a generic standard. |
| Pigment loading | Concentration can affect shade, opacity and apparent color shift | Test both full shade and reduction or let-down shade. |
| Additives and solvents | Plasticizers, waxes, dispersants, stabilizers and solvents can affect stability | Run the full formulation when possible. |
| Reprocessing | Regrind or repeated extrusion adds extra heat history | Check color after repeated processing if recycling or regrind is expected. |
This is why two pigments with the same color family can perform very differently in the same process.
Plastics and masterbatch: heat is usually the first screen
In plastics, heat resistance is often a pass-or-fail requirement. The pigment must survive compounding, extrusion, injection molding, blow molding, film, fiber or sheet production. Engineering plastics and fibers can be especially demanding because processing temperatures and residence times are higher.
Use this practical screen:
| Plastic process | Main heat concern | What to test |
|---|---|---|
| PE and PP masterbatch | Extrusion temperature, dispersion and repeated heat history | Let-down shade, specks, color strength and heat aging. |
| PVC | Heat stability, plasticizer effects and bleeding risk | Shade after processing, contact staining and storage stability. |
| ABS and PS | Color shift, gloss and molded part appearance | Molded plaques, full shade and tint shade. |
| PA, PET and PC | High processing temperature and chemical stability | Peak temperature, residence time and reprocessing. |
| Fiber and thin film | Heat stability plus dispersion defects | Filter pressure, specks, fiber breaks or film appearance. |
For plastic buyers, also review How to Choose Pigments for Plastics and Masterbatch because heat resistance should be checked together with dispersion, migration and dimensional stability.
Coatings: powder coating and baked systems need special attention
Many liquid coatings do not expose pigments to extreme temperature, but powder coating and baked industrial coatings are different. Curing temperature can cause shade drift, darkening or loss of color strength if the pigment is not stable enough.
| Coating system | Heat question | Practical note |
|---|---|---|
| Powder coating | Can the pigment survive extrusion and cure schedule? | Check both powder production and final baking conditions. |
| Baked industrial coating | Will the shade change after oven exposure? | Test the actual time and temperature, not only room-temperature color. |
| Exterior coating | Does heat combine with UV and weathering? | Heat resistance should be reviewed with light fastness and weather resistance. |
| Water-based coating | Does drying or baking affect shade and dispersion? | Confirm heat stability in the final binder and pH range. |
For coating-specific selection, see How to Choose Pigments for Coatings and the coatings application page.
Inks: heat resistance depends on the print structure
Printing inks often use lower processing temperatures than plastics, but heat can still matter. Flexible packaging, laminating inks, heat-seal areas, drying tunnels, overprint varnish and industrial printing can expose pigments to thermal stress or solvent attack.
Ask these questions before approving an ink pigment:
- Is the ink solvent-based, water-based, offset, gravure, flexo or another system?
- Will the printed layer be laminated, heat sealed or overprinted?
- Does the pigment need resistance to hot water, steam, hot filling or sterilization conditions?
- Does the ink require transparency, high gloss or strong tinting strength after drying?
- Are there food packaging or regulatory document requirements?
A pigment suitable for general printing ink may not be suitable for every heat-seal or packaging structure. Use the printing inks application page as a starting point, then confirm with printed film or packaging tests.
Organic vs inorganic pigments for heat resistance
Inorganic pigments often have strong heat stability, opacity and durability, but the shade range can be less bright. Organic pigments often provide brighter shades and higher color strength, but heat resistance varies widely by chemistry and grade. High-performance organic pigments such as DPP, quinacridone, anthraquinone, perylene, phthalocyanine and dioxazine families can be useful where both color strength and heat stability are needed.
| Pigment type | Heat resistance pattern | Buyer takeaway |
|---|---|---|
| General organic pigments | Can be limited in high-temperature processing | Use for lower-temperature applications only after checking TDS and trials. |
| High-performance organic pigments | Often stronger heat, light and migration performance | Good candidates for plastics, powder coating and demanding inks. |
| Inorganic pigments | Often strong heat stability and opacity | Useful when durability and hiding power matter more than maximum brightness. |
For a broader comparison, read Organic Pigment vs Inorganic Pigment.
Fortune Chem product examples
Fortune Chem product pages list heat resistance and application suitability so buyers can build a first shortlist before requesting samples.
| Requirement | Example grades | Why they may fit |
|---|---|---|
| High heat yellow | Pigment Yellow 150, Pigment Yellow 110 | Listed heat resistance around 300-320 C with plastics and coating suitability. |
| Durable red | Pigment Red 254, Pigment Red 122, Pigment Red 177 | High-performance reds for buyers comparing heat and light fastness. |
| Orange under heat | Pigment Orange 64, Pigment Orange 36 | Useful orange candidates where heat resistance is part of the shortlist. |
| Blue and violet | Pigment Blue 60, Pigment Violet 23, Pigment Violet 19 | Strong options for industrial blue, violet and shading work. |
| Inorganic blue | Pigment Blue 29 | Ultramarine blue option where inorganic pigment behavior fits the resin or coating. |
These are not automatic approvals. The final grade should be confirmed in the buyer's own resin, coating binder or ink system.
Common heat resistance failure signs
Watch for these signs during sample testing:
- shade becomes dull, brownish or darker after heating;
- tint strength drops after extrusion, molding or baking;
- color changes after repeated processing or regrind;
- specks or agglomerates appear after compounding;
- bleeding or migration increases after heat aging;
- gloss or surface appearance changes in coatings or inks;
- customer color standard fails after production rather than after lab drawdown.
If these appear, do not simply increase pigment loading. A higher-performance grade, different dispersion process or different pigment chemistry may be needed.
Testing workflow before bulk order
Use this workflow when heat resistance matters:
- Define the application: plastics, masterbatch, powder coating, baked coating or printing ink.
- Record the real process temperature, time and resin or binder system.
- Shortlist pigments by TDS heat resistance, light fastness and application suitability.
- Request TDS, SDS/MSDS, COA and samples.
- Run lab trials at normal and slightly severe conditions.
- Compare color before and after heat exposure in full shade and reduction.
- Check dispersion, migration, gloss, opacity and storage stability.
- Approve bulk purchase only after production-like testing.
Documents to request
Before scaling from sample to bulk order, request:
- TDS with heat resistance, light fastness and application recommendations;
- SDS or MSDS for handling and safety review;
- COA for batch-specific quality data;
- sample reference for shade comparison;
- compliance documents required by the destination market or final customer.
If heat resistance is critical, share your process temperature and application when contacting Fortune Chem. The team can recommend a practical shortlist and samples for evaluation.
Frequently Asked Questions
What does pigment heat resistance mean?
Pigment heat resistance means the pigment can keep its shade, color strength and key performance after exposure to processing or service temperature. It should be tested in the actual resin, coating binder or ink system.
Is the TDS heat resistance value enough for approval?
No. The TDS value is a useful first screen, but final approval should include the buyer's real process temperature, residence time, resin or binder, additives and final performance tests.
Which applications need high heat resistant pigments?
High heat resistant pigments are especially important for plastics, masterbatch, engineering polymers, fiber, powder coating, baked coatings and packaging inks that face heat sealing or hot filling.
Are inorganic pigments always more heat resistant than organic pigments?
Not always. Many inorganic pigments have strong heat stability, but some high-performance organic pigments also offer excellent heat resistance. Buyers should compare the exact C.I. pigment grade and test it in the final application.
What should I send when asking for a heat resistant pigment recommendation?
Send the application, resin or binder, process temperature, residence time, target shade, required light fastness and documents. This information helps the supplier recommend suitable grades faster.
