Polymer

technologies

Our portfolio includes polymer dispersions with two different crosslinking mechanisms on the same polymer backbone. The self-crosslinking of the polymers takes place only during film formation by drying at room temperature. In this way, the typical properties of a crosslinked polymer – for example, increased chemical resistance, water and stain resistance or improved adhesion properties – can be achieved without limiting the storage stability. High-performance coatings on concrete or wood in interior and exterior applications, as well as overprint varnishes, benefit from this in particular.

Using a two-step synthesis process, multiphase technology combines two different types of polymers in the same polymer network. This allows a balanced combination and thereby an overall improvement of the physical properties of the two polymers. Hardness and chemical resistance of these polymers are balanced. At the same time, the polymers have a moderate film-forming temperature. This is particularly advantageous for applications with low curing temperatures, e.g. applications in the wood sector or the graphic arts industry. This process also means that no or only a small amount of emulsifiers is required. Thus, some of these products are approved for indirect food contact in compliance with the FDA and Swiss Ordinance and are therefore suitable for applications in the packaging sector.

Zschimmer & Schwarz offers polycationic systems with an optimal acidic pH range and high charge density. By complexing anionic structures such as wood extractives or water-soluble soils, these products show outstanding stain blocking. Cationic resins provide excellent adhesion to various critical anionic surfaces and form an excellent ink-receptive layer. The polymers form soft to medium-hard films and are suitable for colourless and glossy films as well as for highly pigmented and low-VOC systems. In wood applications, these polymers provide a protective film with good sanding resistance and do not tend to discolour the wood due to their low pH. On porous substrates, the small particle size also leads to good penetration into the substrate, which further improves adhesion and protection. These properties make these polymers especially well suited for use in isolation primers on wood and metal as well as for applications in the graphic arts sector.

The IPN involves two different ionic structures in the same polymer network at a neutral pH value. Overall, the polymer exhibits an anionic behaviour and can thus be formulated like an anionic polymer. Cationic functionalities then form during drying, providing excellent tannin, stain and dye blocking without the compatibility problems common to cationic polymers. Adhesion to various substrates such as aluminium, PVC or wood is also improved. At the same time, VOC requirements for the formulation remain low.

Our wax-hybrid technology is a patented process for combining wax and acrylate in a single polymer network. This prevents the wax from migrating to the surface as it dries, resulting in a more uniform film composition that improves the appearance and performance of the coating. The hybrid polymer exhibits anionic behaviour and broad compatibility with other water-based polymers. The positive properties of waxes, such as increased slip or abrasion resistance and improved water resistance, can thus be optimally utilised.

Our alkali-soluble polymers are based on polyacrylic and polymethacrylic acids with high electrostatic repulsion. They are available with different acid numbers, molar weights and glass transition temperatures as a clear solution in water. The resin solutions offer excellent dispersibility of pigments and high compatibility and stability in various formulation types. This provides improved wetting and increased gloss of formulations. Unlike dispersing additives, these resins form a hard, water-soluble film at room temperature and are thus part of the binder. On some substrates such as steel, adhesion can also be positively influenced.

Using a proprietary process, Zschimmer & Schwarz offers an inherently matte acrylate polymer. After drying, a film with low gloss, high flexibility and excellent stability is formed. This technology also provides excellent adhesion to various substrate types. The polymer is a matte binder and not a "liquid matting agent", meaning it can be formulated as a conventional (water-based) acrylic polymer, replacing the binder. It can be used as a single binder or in a blend with polyurethanes and has low foaming and low VOC requirements. The time- and labour-consuming incorporation of solid matting agents is completely eliminated, making the formulation much simpler, more stable and more economical. Unlike conventional matting agents, the matte polymer also has excellent transparency.

In the field of polyurethane dispersions, Zschimmer & Schwarz offers specialised solutions of both anionic and cationic water-based polyurethane dispersions (PUDs). The self-crosslinking (self-emulsifying) PUDs are characterised by strong intermolecular bonding without the use of emulsifiers. The PUDs show excellent compatibility with additives in formulations and outstanding chemical resistance with high impact strength and heat resistance. Customised PUDs with adjusted particle sizes can be tailored to your requirements.