Bayer aim for high quality end16 April 2003
BAYER CHEMICALS will be presenting a comprehensive range of speciality chemicals for high-quality leather from the beamhouse to finishing. The main focus this year is on leather preservation, upper leather and waterproofing. 'We are already one of the leading suppliers of leather chemicals and technology worldwide', says Dr Bernhard Wehling, head of the Leather Business Unit. He sees the cornerstones of Bayer's expertise as being in the field of chrome tanning materials, synthetic and polymer tanning materials and polyurethane and acrylic dispersions for the finishing process. 'With these core competencies we want to continue to expand and offer our customers top-quality products.' The leather industry was recently faced with a new challenge through the need for NMP-free polyurethane products for the finishing process. With their high quality and excellent stability, polyurethane dispersions are ideal when it comes to producing lacquers and coatings. In summer 2001, however, the use of numerous polyurethane dispersions containing the co-solvent N-methyl-pyrrolidone (NMP) was jeopardized when this compound was included in 'California Proposition 65'. Following this development, there was an immediate call in the leather sector for NMP-free dispersions. Bayer Chemicals took up the challenge and can now offer some new NMP-free dispersions in addition to the numerous products which were already NMP-free. Aquaderm Matting Agent HPM (High Performance Matting Agent), for example, is a general-purpose, NMP-free matting agent. Three new products have been added to the range of leather preservatives: Preventol OT-L and Preventol CT-L are optimized formulations developed in response to specific regional requirements. In these products, the phenolic active ingredients PCMC (p-chloro-m-cresol) and OPP (o-phenylphenol) have each been combined with one other active ingredient. Preventol OT-L, which is based on OPP, is free of adsorbable organic halogen compounds (AOX) and has an emulsifying system that improves the penetration of the active ingredient. Preventol CT-L is an OPP-free emulsifier formulation based on PCMC. The TCMTB-free formulation Preventol C 40-L, a water-based, surfactant-free formulation with PCMC as its active ingredient, has US EPA approval and also complies with the special regulations that apply in California. The particular advantages of this product are its long-term effectiveness, its reliability in application and its ecological compatibility. Another innovation is fragrance-filled microcapsules for providing automotive, furniture and clothing leather with a particular aroma. The dispersions Euderm Aroma BL and Euderm Aroma CV give a neutral 'characteristic' aroma, while the new, water-soluble Euderm Aroma NE is used to neutralize unpleasant odours. The product is particularly effective at combating odours caused by low-volatility, organic compounds such as fish oils, train oils and organic acids from perspiration. Bayer's presentation will also highlight the Xeroderm waterproofing system, in which fixation is carried out without mineral salts. Shoe upper and clothing leathers treated by this system are waterproof, yet at the same time water-vapour-permeable, which means they are comfortable to wear. There is also no shifting of the shade, no matter whether the leather is dyed in brilliant colours or in pastel shades. Baygen Hardener CF, a cross- linking agent based on isocyanate, significantly improves the performance properties of patent leather even during the cold winter months. It gives excellent cold flex resistance and drastically reduces the risk of cracking. Last but not least, the Bayer Wuxi Leather Chemical Co Ltd will be presenting a new technology for the finishing process. The preground is carried out with the cationic products Bayderm Cationbase U, Euderm Filler CF-DP 2022 and Euderm Cationblack KC because of their good covering power and leveling properties, but especially because of their outstanding gloss. For modern pull-up effects, Bayderm Bottom 51 UD is used. In combination with casein, this gives a high gloss.