Patent leather chemical technology
19 June 2012Patent leather is a fashion classic, especially for shoes and bags. However, gone are the days when consumers were satisfied with standard black or white. Now, for example, they want bright colours, special effects, or a matt or deep luster. In addition to mastering these challenges, leather manufacturers today have to satisfy numerous technical requirements, too, as patent leathers are also expected to have good lightfastness, cold flex resistance, heat stability and elasticity.
Lanxess offer an integrated range of products that are specifically geared to the finishing of patent leather. ‘Patent leather is very much in fashion. We want to offer products that help tanners meet their customers’ wishes quickly and reliably,’ says Bianca Verstegen, Head of Global Product Management Finishing in Lanxess’ Leather business unit. ‘So what we need is a range of leather chemicals that have been specially developed for this purpose, are compatible with one another and make it possible to adjust all the desired properties. We have many years of experience in this field. For example, our Baygen patent finish with two-component aromatic and aliphatic polyurethane systems has been setting the standard for almost 60 years,’ she adds.
Modern Baygen products still form the core of the range. Base coats based on Baygen Compact give uniform, elastic films that meet the most rigorous requirements. Acrylic-based Baygen Compact CC2, for example, provides highly economical, transparent, medium-hard films with good adhesion especially for full grain leather and small skins.
The range also includes both general-purpose products such as Baygen Top U 01 and specialties such as Baygen Top MS for use in top coats. The gloss level of the patent finish can be adjusted at will by varying the mixing ratio of these two grades.
Customized components are available for brilliant white and black lacquers with outstanding covering power or for special, thermally resistant formulations. These can be combined with various products from the Baygen Hardener range to obtain standard lacquers or lacquers with particularly high lightfastness or cold flex resistance. The colourless, solvent-based nitrocellulose formulation Isoderm LO 87 and the aqueous polyurethane/acrylic system Bayderm Finish UP-G are ideal for effect lacquers or for fixations.
Bayderm Finish F 2 is an aqueous polyurethane system that makes it possible to produce high-gloss patent leather by simple rollercoating or spraying as compared with the usual curtain coating process. The resultant lacquer coat is highly transparent and has excellent mechanical fastness properties. ‘This system is particularly suitable for tanneries that have not produced patent leather before or which don’t yet produce enough to justify major expenditure on plant,’ says Verstegen.
The finishing products for patent leather are rounded off by acrylic blends from the Primal Prebottom range for tightening the grain (impregnation) and by Baygen X-Grade ST, a system specially modified for patent leather for concealing hide defects. The filling effect of all the X-Grade brands is based on a microcapsule technology that was specially developed for use on leather. A wide range of colors and individual effects can be obtained with the brilliant anionic Levaderm dyestuffs.
An overview of the Lanxess range for patent leather is included in our ‘Patent Leather’ brochure, available in Chinese, English and Italian, which can be obtained by sending an e-mail to leather@lanxess.com.
