Polyaziridines are very versatile molecules with wide-ranging usage in coatings and adhesive applications. Acrylic emulsions and polyurethane dispersions utilize nucleophilic carboxy groups, and polyfunctional aziridines are used to cross-link these resins. These cross-linkers are used to improve both physical and chemical properties for both aqueous and non-aqueous coatings as well as a range of inks and adhesives.
Pressure Sensitive Adhesives
Polyfunctional aziridines improve the performance of pressure sensitive adhesives such as tapes, labels and automobile trim. Easily mixed and dispersed into adhesives, polyfunctional aziridine provides the following benefits for this type of adhesive:
- Increased cohesive strength
- Improved adhesion to film layer
- More vibrant color and clarity
- Faster cure time
Wood Coatings
Wood coatings often are slow to dry and highly abrasive. Polyfunctional aziridine resins work to cross-link acrylic emulsions and polyurethane dispersions to utilize nucleophilic carboxy groups. Along with a faster cure time and enhanced performance of low volatile organic compound (VOC) formulations, polyfunctional aziridine products are also easily mixed and dispersed into coatings. In addition, many long-term effects are also realized as a result:
- Improved water and chemical resistance
- Increased resistance to black heal marking
- Better abrasion resistance
- Enhanced color and clarity
Protective Films
Protective films for paints, windows or windshields have to withstand a lot of wear and tear due to heavy traffic and exposure to different types of light sources. Along with a faster cure time, the addition of polyfunctional aziridines also modifies adhesion characteristics of the films.
Printing Inks
Printing inks are used on a variety of surfaces, not all of which are ideal for the inks to adhere. The ease at which polyfunctional aziridines are mixed and dispersed into the ink makes it an excellent solution for this problem. In addition to a faster cure time, polyfunctional aziridines improve printing inks in the following ways:
- Improved adhesion to difficult substrates
- Increased scuff, chemical and water resistance
- Enhanced color and clarity
- Better cross-link density
Leather Coatings
Additional surface protection is often needed for leather coatings, as they are typically manufactured with softer polymers. Polyfunctional aziridine products can add to this protection with the added benefit of a fast cure time. PolyAziridine’s PZ-28 and PZ-33 products help increase chemical and water resistance and can also improve wear resistance.
Adhesives
The best performing adhesive is one that has the ability to hold objects together for a long period of time across a variety of applications. The addition of polyfunctional aziridines to adhesive formulations results in faster cure time, increased cohesive strength, and the improved ability to adhere to difficult substrates.
Textile Coatings
Textile coatings are necessary for anything from home furnishings to automotive to industrial textiles. Adding polyfunctional aziridines to textile coating formulations increases chemical and water resistance, improves wear resistance and allows for a faster cure time.
Over-Print Varnishes
Overprint varnishes (OPVs) are coatings applied to an already printed sheet in order to elongate the life of the material. Polyfunctional aziridines can be easily mixed and dispersed into these types of varnishes to obtain several key benefits:
- Increased scuff, chemical and water resistance
- Enhanced color and clarity
- Improved cure time
- Better cross-link density
Plastic Films
Plastic films are used in a wide variety of applications including: landscaping, construction of buildings, packaging and film stock. Adding polyfunctional aziridines to plastic film formulations improves coating adhesion, increases anti-static properties and provides enhanced anti-blocking properties. Photographic films also have many of the same benefits as plastic films: improved coatings adhesion and increased anti-static properties.