Lanxess Launches High-Performance Polyurethane Dispersions

Industry demand for sustainable coatings and adhesive solutions has driven the transition from solvent-based systems to water-based systems in recent years. More than 40 years ago, Witcobond® polyurethane dispersions (PUD) were developed to help customers comply with increasingly stringent regulatory requirements concerning volatile organic content (VOC) while simultaneously providing suitable solutions. In addition, specialized work has been conducted according to particular application requirements in Witcobond® product development to create high-performance and high-solids products. Today, polyurethane dispersions under the Witcobond® brand provide variety, performance, innovation and specialized advantages to users across many different fields.

Advantages of Witcobond® PUD

• Portfolio with strong performance at high solids levels, • Water-based blocked crosslinkers for 1K and 2K oven systems, • More than 40 years of experience and ability to customize for applications, • High quality and product consistency. Formulators of water-based coating systems can choose from a wide variety of Witcobond® polyurethane dispersions. Lanxess offers ester and ether types as well as anionic, nonionic and cationic grades. With Witcobond® products, it is possible to provide variations in final coating properties such as hardness, flexibility, toughness and chemical resistance.

Matte Surface Appearance with Witcobond 391-64

Witcobond® polyurethane dispersions can be crosslinked with various agents to further improve chemical resistance, coating adhesion and durability. Lanxess's Trixene® Aqua product group contains water-dispersed blocked crosslinkers and adhesion promoters for formulating 1K or 2K oven systems. When heated, these multifunctional blocked isocyanates begin to crosslink with complementary functional groups in the coating and substrate.

Key Properties

• Solids content ranges from 30% to 60% by weight. • Offers grades without auxiliary solvents and surfactants for optimization. • Meets HS&E requirements. • Specialized grades for particular coating requirements (e.g. matte surfaces or soft touch). • Shows compatibility with various aqueous binders such as acrylic dispersions. • Compatible with pigments, matting agents, flame retardants and other auxiliaries. Witcobond® polyurethane dispersions address specialized applications. Fiber Sizing and Composites Lanxess polyurethane dispersions are widely used in the fiber sizing industry and can be adapted for new requirements. In fiber and composite processing, they ensure superior adhesion of filaments with performance and achieve exceptional physical properties in final applications. Witcobond® 374-13 is a polyester-based polyurethane dispersion commonly used as a film former in glass sizing recipes. It provides excellent integrity for chopped strand production and good adhesion with various thermoplastic and thermoset matrices. Adhesion between matrix and fiber can be further improved using blocked isocyanate technology. Specialized polyurethane dispersions can be produced with blocking groups on the polymer backbone, or additives such as Trixene® Aqua BI 201 can be added to standard-sized formulations.

Soft Touch Coatings

Soft grades such as Witcobond® 374-13 can be included in coating formulations that modify the haptics (tactile hardness perception) of normally hard surfaces. Such coatings are used, for example, in automotive interiors and electronic components, providing enhanced aesthetics.

Coating Hard Surfaces

Alternatively, hard products such as Witcobond® 781 and Witcobond® 457-66 can be used in durable, chemically resistant 1K and 2K systems applied to hard surfaces such as wood, metals, glass, plastic, concrete and walls.

Textile Processing

Water-based polyurethane dispersions such as Witcobond® 363-02 and Witcobond® 737 are widely used in textile processing. Typical applications include fully waterproof and weather-resistant coatings, back coatings, lamination adhesives, pigment binders used in textile printing, and garments with imperceptible surfaces on yarns and fibers. Other functional textile uses include protective coatings on belts, ropes, braids, optical fibers and filament yarns. Urethane coatings require abrasion, chemical and UV resistance, areas where Lanxess can provide a range of solutions. Lanxess operates a specialized polyurethane dispersion laboratory in Latina, Italy, capable of meeting market requirements in various coating and adhesive applications. The experienced technical team has the capability for analytical studies of new products, formulation development and synthesis with a high degree of technical differentiation. With the Witcobond® product group, Lanxess supports users in a wide range of applications including glass fiber sizing, plastic, glass and metal surfaces, coatings and textile finishing. Growing demand for VOC-free and low carbon footprint materials, combined with increased regulatory pressure on restricted chemicals, has enabled Lanxess's applied research into water-based technologies to provide Witcobond® users with greener technologies and chemistry.

Ece Okçu Sales Manager, C.A.S.E. PU Kimsel