Polyurethane Dispersions

Polyurethane Dispersions for Coatings, Adhesives and Sealants Over past decades, because of increasing environmental concerns and sustainability requirements, industrial demand for coating and adhesive solutions has begun shifting from solvent-borne towards water-based systems. Therefore, access to water-based systems has become critical. Witcobond® PUDs offer innovative and effective solutions for water-based polyurethane systems in many industries. More than 40 years ago Lanxess developed Witcobond® polyurethane dispersions (PUD). These dispersions enable customers to comply with stringent regulations on volatile organic content (VOC). Another advantage of these PU dispersions is their ability to provide high-performance and high-solids products, allowing them to address specific application needs. Lanxess' portfolio is complemented by special blocking technology offering fully reacted polyurethane dispersions combined with blocked systems for 1K and 2K stoving applications.

Benefits of Witcobond® PUD

• Balanced portfolio with strong performance in high solids grades, • Water-based blocked crosslinkers for 1K and 2K stoving systems, • More than 40 years of experience and ability to customize for applications, • High quality and batch-to-batch consistency.

Providing a Range of Solutions to Satisfy Required Levels of Performance and Durability

Witcobond® polyurethane dispersions cover a broad range of products that formulators can choose according to their water-based coating systems for their specific needs. Lanxess Witcobond® PU products are available in both ester and ether types with anionic, nonionic and cationic grades. Formulators of water-based coating systems can choose from our broad range of products. For properties such as hardness, flexibility, toughness and chemical resistance, these PU dispersions can help formulators achieve different variations.

Key Features:

• Solids contents varying from 30% to 60% w/w, • Co-solvent and surfactant-free grades available for optimizing health, safety and environment requirements, • Compatibility with a wide range of aqueous co-binders, such as acrylic dispersions, • Compoundable with pigments, matting agents, flame retardants and other auxiliaries.

WITCOBOND® Polyurethane Dispersions Can Be Used in Water-Based Coatings With or Without Crosslinkers

To improve properties such as chemical resistance, coating adhesion and product robustness, Witcobond® polyurethane dispersions can be crosslinked with various agents. Trixene® Aqua range, part of the Lanxess family, can be used for 1K or 2K stoving systems. Trixene® Aqua contains water-dispersed latent crosslinkers and adhesion promoters. Under heat, these blocked isocyanates begin crosslinking with complementary functional groups in the coating and substrate.

Fiber Sizing and Composites

The fiber sizing and composites industry is one of the most dynamic and critical sectors today. Lanxess polyurethane dispersions are widely used in the fiber sizing industry. Moreover, these products can be tailored for new requirements. Witcobond® polyurethane dispersions offer superior bonding of filaments in fiber and composite processing, and outstanding physical properties in end applications. Witcobond® 374-13 is a polyester-based polyurethane dispersion commonly used as the film former in glass sizing recipes. It provides excellent integrity for chopped strand production and good adhesion with various thermoplastic and thermosetting matrices. Adhesion between matrix and fiber can be further improved using blocked isocyanate technology. Additives such as Trixene® Aqua BI 201 can be added to standard size formulation to obtain alternative solutions.

Soft Touch Coatings

Soft grades such as Witcobond® 374-13 can be incorporated into coating formulations that modify the haptics of normally harsh surfaces. Such coatings protect base materials used in, for example, automotive interior facias and electronic components, and provide improved aesthetics. Coating of Hard Substrates 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 substrates such as wood, metals, glass, plastics, concrete and masonry. These application areas can be critical for today's fast-moving and changeable environment.

Textile Processing

In textile processing, waterborne polyurethane dispersions such as Witcobond® 363-02 and Witcobond® 737 are widely used. Typical applications include fully waterproof and weatherproof coatings, back coatings, laminating adhesives, pigment binders used in textile printing, and imperceptible finishes on yarns and fibers for clothing. Other functional textile uses include protective coatings on belts, ropes, braids, optical fibers and filament yarns. Lanxess' applied research in water-based technologies presents greener technologies and chemistry for customers, formulators and end-users. Besides polyurethane dispersions for coating, adhesive and sealant applications, the portfolio includes products such as blocked isocyanates, blocked prepolymers and innovative Low Free (LF) isocyanate systems. All of these products can provide key solutions for your systems and help achieve expected properties in your products. Özlem Erkan Asmaoğlu PU & Coating Additives Technical Sales Engineer Kimsel Kimya