PUE Polyether Polyol Color Paste: Applications in Polyurethane Systems

Introduction

Polyurethane (PU) systems are among the most versatile polymer platforms in modern industry, covering flexible and rigid foams, elastomers, coatings, adhesives, sealants, and composite profiles. Achieving consistent, durable coloration across these diverse chemistries requires a colorant that is chemically compatible with the polyol component, thermally stable during processing, and resistant to migration throughout the product's service life.

Henvastness PUE series polyether polyol color pastes are pre-dispersed pigment concentrates using polyether polyol as the carrier resin. Because the carrier shares the same molecular backbone as the polyol component in most PU formulations, these pastes integrate seamlessly without affecting foam rise, gel time, or mechanical properties. This article provides a comprehensive overview of the PUE product range, five major application scenarios, and practical guidance on model selection.

Product Overview and Key Benefits

Carrier Chemistry

PUE color pastes use a phthalate-free, solvent-free polyether polyol carrier. The carrier's hydroxyl value is tightly controlled to minimize any impact on the NCO/OH stoichiometry of the host formulation. Moisture content is kept below 0.6% (PUE-902D Super White below 0.1%) to prevent CO₂ generation from NCO–water side reactions.

Core Advantages

| Advantage | Description | |---|---| | No Structural Disruption | Does not affect foam cell stability, nucleation, or profile lift | | No Shelf-Life Impact | Does not alter start, gel, or demold times | | Machine-Foam Compatible | Stable coloring at high metering ratios without process drift | | Migration Resistant | Pigment locked into the polymer network via reactive carrier | | Wide Thermal Window | Heat resistance from 190 °C to 280 °C depending on model |

Full Color Chart

Black, White, and Yellow Range

| Model | Color Name | Pigment | CI Number | Concentration | Heat Resistance | Light Fastness | |---|---|---|---|---|---|---| | PUE-1200 | Deep Black | Pigment Black 7 | CI 77266 | 30% | 260 °C | 8 | | PUE-902D | Super White | Pigment White 6 | CI 77891 | 70% | 250 °C | 8 | | PUE-21 | High-Strength Bright Yellow 138# | Pigment Yellow 138 | CI 56300 | 35% | 245 °C | 8 | | PUE-25 | Lemon Yellow | Pigment Yellow 81 | CI 21127 | 25% | 200 °C | 5–6 | | PUE-26 | Organic Yellow | Pigment Yellow 14 | CI 21095 | 30% | 190 °C | 4–5 | | PUE-28 | Golden Yellow | Pigment Yellow 83 | CI 21108 | 25% | 210 °C | 7 | | PUE-29 | High-Strength Golden Yellow 139# | Pigment Yellow 139 | CI 56298 | 30% | 245 °C | 8 |

Red, Violet, Blue, and Green Ranges

| Model | Color Name | Pigment | CI Number | Concentration | Heat Resistance | Light Fastness | |---|---|---|---|---|---|---| | PUE-36 | Bright Red | Pigment Red 170 | CI 12475 | 30% | 200 °C | 7 | | PUE-37 | Vivid Red | Pigment Red 170 | CI 12475 | 30% | 200 °C | 7 | | PUE-38 | China Red | Pigment Red 254 | CI 56110 | 30% | 280 °C | 8 | | PUE-39 | Heat-Resistant Rose Red | Pigment Red 176 | CI 12515 | 30% | 280 °C | 8 | | PUE-52 | Peach Pink | Pigment Red 122 | CI 73915 | 20% | 280 °C | 8 | | PUE-53 | Violet | Pigment Violet 23 | CI 51319 | 20% | 280 °C | 8 | | PUE-65 | Phthalocyanine Blue | Pigment Blue 15:3 | CI 74160 | 30% | 260 °C | 7–8 | | PUE-67 | Phthalocyanine Green | Pigment Green 7 | CI 74260 | 25% | 260 °C | 5 |

A fluorescent paste series using an aminosulfonic resin carrier in polyether polyol is also available for high-visibility safety and signage applications.

Five Key Application Scenarios

1. Flexible and Rigid Polyurethane Foam

Flexible slabstock foam for furniture cushions, mattresses, and molded automotive seating requires colorants that do not disrupt the delicate balance of blowing catalysts, surfactants, and isocyanate reactivity. PUE color pastes are added directly to the polyol stream at 0.5–3.0 phr for saturated tones and 0.05–1.0 phr for tinting. The polyether polyol carrier ensures uniform distribution through high-pressure mixing heads without clogging filters or altering cream/gel times.

For rigid insulation foam in appliances, continuous laminates, and spray-applied building insulation, thermal stability during the exothermic cure is critical. Models such as PUE-38 (China Red, 280 °C) and PUE-1200 (Deep Black, 260 °C) maintain color integrity even at peak core temperatures exceeding 180 °C.

Recommended models:PUE-1200, PUE-902D, PUE-21, PUE-38, PUE-65

2. PU Adhesives and Structural Bonding

One- and two-component polyurethane adhesives require colorants that remain stable during extended shelf life and do not catalyze premature moisture cure. The low-moisture specification of PUE pastes (< 0.6%) prevents CO₂ bubble formation in sealed adhesive cartridges. The reactive carrier participates in the urethane linkage during curing, eliminating plasticizer-like migration that could weaken bond lines over time.

Typical addition levels range from 0.1 to 1.0 phr for identification tinting and up to 3.0 phr for fully pigmented structural adhesives.

Recommended models:PUE-1200, PUE-902D, PUE-36, PUE-65

3. Industrial and Chemical-Resistant Flooring

Self-leveling and poured polyurethane floors are exposed to chemical spills, UV light, and heavy mechanical traffic. Ensuring color consistency across large pour areas and long-term colorfastness is critical. PUE color pastes with light fastness ratings of 7–8 (Blue Wool Scale) minimize fading under indoor fluorescent lighting and occasional sunlight exposure through skylights.

For outdoor terraces and sports surfaces, PUE-38 and PUE-39 provide heat resistance up to 280 °C, supporting hot-pour application methods and high summer surface temperatures.

Recommended models:PUE-21, PUE-29, PUE-38, PUE-39, PUE-65, PUE-67

4. Artificial Turf Backing and Sports Surfaces

Artificial turf backing compounds are typically filled polyurethane or SBR-latex-modified PU systems applied at high solids and cured at elevated temperatures. The colorant must withstand calendering and oven curing without volatilizing or shifting hue. PUE-67 (Phthalocyanine Green, 260 °C) and PUE-21 (Bright Yellow, 245 °C) are widely used to match natural grass tones and field marking colors.

The reactive carrier's non-migrating nature prevents color transfer to athletes' clothing and equipment—a common issue with conventional solvent-based pigment pastes.

Recommended models:PUE-21, PUE-25, PUE-67, PUE-1200

5. PU Pultrusion and Composite Profiles

Continuous pultrusion of polyurethane-matrix profiles for window frames, cable trays, and structural components requires a colorant that disperses uniformly in the resin bath and withstands die temperatures of 180–220 °C. PUE color pastes are dosed into the polyol upstream of the impregnation zone to ensure consistent color throughout the cross-section.

Models with heat resistance ≥ 245 °C (PUE-21, PUE-29, PUE-38, PUE-39, PUE-52, PUE-53, PUE-65) offer a wide range of colors for architectural and industrial profiles, maintaining color stability throughout the pultrusion process.

Recommended models:PUE-21, PUE-29, PUE-38, PUE-52, PUE-53, PUE-65

Model Selection Guide

When choosing a PUE model for your application, consider these factors:

| Factor | Guidance | |---|---| | Processing Temperature | Select a model with heat resistance at least 20 °C above your peak process temperature. | | Light Exposure | For outdoor or UV-exposed applications, choose models with light fastness ≥ 7. | | Color Depth | Use 0.5–3.0 phr for saturated colors; 0.05–1.0 phr for tinting and shading. | | Moisture Sensitivity | For moisture-curing adhesives and sensitive foam systems, prefer PUE-902D (< 0.1% moisture). | | Regulatory Compliance | All PUE models are phthalate-free and solvent-free, suitable for REACH-compliant formulations. | | Fluorescent Requirements | Contact technical support for the fluorescent paste series used in safety and signage applications. |

Technical Specifications Overview

| Parameter | Specification | |---|---| | Carrier | Polyether polyol (phthalate-free, solvent-free) | | Moisture Content | < 0.6% (PUE-902D < 0.1%) | | Dosage Range | 0.5–3.0 phr (saturated), 0.05–1.0 phr (tinting) | | Light Fastness | 1–8 (Blue Wool Scale) | | Migration / Acid / Alkali / Oil / Water Resistance | 1–5 rating | | Heat Resistance | 190–280 °C (model dependent) | | Packaging | 25 kg PE drums, 200 kg steel drums, custom available | | Shelf Life | 24 months from date of manufacture | | Storage | Seal at 5–35 °C, keep away from direct sunlight |

Frequently Asked Questions

Can PUE color pastes be used in polyester polyol systems?

PUE color pastes are optimized for polyether polyol carriers. They can also be used in polyester polyol systems, but compatibility testing is recommended prior to full-scale production to verify dispersion stability and curing behavior.

Do PUE colorants affect foam density or cell structure?

No. The polyether polyol carrier is chemically identical to the base polyol, so it does not introduce foreign phases that could disrupt cell nucleation or foam rise. Independent testing confirms no measurable change in foam density, compression set, or tensile properties at recommended addition levels.

What is the maximum addition level?

For most applications, 3.0 phr provides deep saturation. Higher loadings may be possible for specialty applications but should be validated to ensure mechanical property retention and process stability.

Are PUE color pastes suitable for food-contact or medical PU products?

PUE color pastes are phthalate-free and solvent-free. However, regulatory compliance for food-contact or medical applications depends on the specific pigment and end-use conditions. Contact our regulatory team for application-specific guidance.

How should PUE color pastes be stored?

Store sealed containers at 5–35 °C, away from direct sunlight. Gently stir before use if the material has been stored for an extended period. Shelf life is 24 months from the date of manufacture when stored under recommended conditions.

Conclusion

Henvastness PUE polyether polyol color pastes deliver a reliable, chemically compatible coloring solution for all polyurethane applications. With 15 standard colors plus a fluorescent series, heat resistance up to 280 °C, and light fastness ratings up to 8, the PUE range covers flexible foam cushioning, rigid insulation, structural adhesives, industrial flooring, artificial turf backing, and pultruded composite profiles. The reactive polyether polyol carrier ensures zero migration, no process disruption, and consistent color quality from batch to batch.

For technical data sheets, sample requests, or custom color matching, pleasecontact our technical team.

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The information in this article is based on current technical knowledge and is intended for general guidance. Users should perform their own validation testing under actual production conditions to confirm suitability for specific applications.