Polyurethanes for yellowing-resistant applications

Aliphatic materials have a high colour stability under UV exposure and are therefore particularly suitable for transparent and light-colored products with a long service life.

These raw materials can be used for various applications in the automotive, textile, sports, leisure or electronics industries.

A selection of aliphatic raw materials is listed below:

1. Thermoplastic polyurethanes TPUs for injection molding, extrusion and calender

Aliphatic Pearlcoat, Pearlthane and Estane TPUs are easy to process materials that meet important OEM specifications in various end applications.

These TPU grades combine outstanding properties of aromatic TPUs, such as high resilience and good processability, with special properties of aliphatic TPUs, such as:

• Excellent colour fastness under UV exposure
• High-quality feel
• Excellent elasticity/resilience properties
• No efflorescence

Aliphatic TPUs based on polycaprolactone polyester: See PEARLTHANE 91T product range.

Aliphatic TPU innovations based on ether: ESTANE 96F85EXP and ESTANE ALR MC-93A-VE.

For these easily colorable aliphatic TPUs, the use of aliphatic masterbatches is recommended: DANCOLOR TPU.

2. Thermoplastic polyurethanes for hot melt adhesives

Yellowing-resistant raw materials can also be used in adhesive applications. Examples of applications are outdoor textiles (awnings, functional clothing) or flat, transparent bonding (glass, safety glass, plastic-glass composites).

Hot melt product innovations include:

PEARLBOND 920L: Highly transparent polycaprolactone polyester TPU with very good adhesion and processing properties.

ESTANE AG 8451-E: TPU based on polyether, specially developed for use as a transparent interlayer film. It can be used universally for surface bonding in optical applications; for example, as adhesive film for glass-polycarbonate composites without surface pre-treatment/primer.

3. Aliphatic 2-component PUR systems / cast elastomers

We are also happy to present liquid cast and spray elastomers. The hardness can be controlled by the mixing ratio (about Shore A90 to D65).

These 2K-PUR casting systems can be processed classically by low-pressure dosing machines to various PUR elastomer components. Selected systems are also suitable for spray application for the production of coatings.

4. Aliphatic PU adducts / solvent-containing coating solution

DANCOLL 244-21E serves as a raw material component for very high-quality primer solutions, which are particularly used for greasy leathers. In the case of porous substrates with low intrinsic strength, the material strengths are significantly increased by pre-coating with DANCOLL 244-21E. Due to its soft, elastic films, DANCOLL 244-21E can be used as a primer for porous materials such as leather, paper and textiles.

5. Aqueous polyurethane dispersions PUD

DANCOLL W150 is an aqueous, well crosslinkable, hard, aliphatic polyurethane dispersion. This product results in dry films that are not thermoplastic. DANCOLL W150 is used as paint, finish and coating binder, textile impregnation and textile finishing dispersion.

6. Additives to increase the UV resistance of aromatic PU systems

The use of UV stabilizers can also reduce and slow down the yellowing of aromatic PUs. For TPUs, the use of additive masterbatches, such as Estane MB ABHU1, is recommended. We can also setup a combination masterbatch according to your needs (individual color + UV additive).

Our team is delighted to provide you with detailed advice on selecting raw materials for your project!