Innovative retanning materials and finishing agents from LANXESS4 September 2006
At the ACLE 2006, chemical company LANXESS will be exhibiting a comprehensive range of products for the leather industry, including the innovations Retingan ZF, LubritanM XB, XS and Tanigan SR-C. The company will also be presenting their new X-tra range of finishing products for highly fashionable upper and bag leathers that meet the toughest requirements. Dr Bernhard Wehling, head of LANXESS' Leather business unit, sees the company's presence at the fair as being extremely important to its Asian business: 'China is still one of the key regions for us and one on which we must continue to focus our attention. This fair is an ideal forum for presenting our innovations to our customers from the Asian market. Another top priority', he continued, 'is the company's comprehensive customer service, which is provided at the customer's plant by local technicians.' Retingan ZF is the first genuine resin retanning material without free formaldehyde. Because of its low astringency, the innovative retanning resin gives a smooth, fine and tight grain with high elasticity. Its selective filling effect for loosely structured parts of the hide makes for an excellent cutting yield, while the outstanding buffing properties result in a uniform, tight and short nap. Leathers treated with Retingan ZF have good lightfastness and resistance to heat yellowing. The product can also be used for white and non-pigmented leathers. Unlike retanning materials that contain emulsifiers, it is also suitable for use in the production of waterproof leathers as it increases water vapour transmission, thus improving the wear comfort. Retingan ZF gives excellent, uniform embossing properties for producing fashionable furniture, automotive and shoe upper leathers. Another retanning product that will be featured is the anionic, synthetic auxiliary Tanigan SR-C which, in addition to having a dispersing and neutralising effect, is also a strong reducing agent - especially for free formaldehyde. Supplied in powder form, it can be used in all the various stages of the retanning process, eg in the neutralisation, retannage and dyeing. 'Tanigan SR-C has proved particularly effective at low to medium float temperatures', says LANXESS leather expert Christopher Henzel. 'We recommend adding 1-2% of the product in the neutralisation and the same quantity in the retannage or dyeing to prevent the formation of free formaldehyde.' The dispersing and neutralising effect helps the other retanning products used to be more uniformly distributed in the leather and also leads to more level dyeings. Rohm and Haas Corp, based in Philadelphia, USA, and LANXESS have cooperated closely on the development of a technology that provides an excellent waterproofing effect coupled with exceptional leather properties. It is based on the modified acrylic polymer LubritanM XB and LubritanM XS, a silicone polymer that improves the dynamic test values. This 'open' waterproofing technology, as it is known, gives lightweight leathers with a tight, dry, natural grain. The Rohm and Haas polymers, which are marketed by LANXESS, fix on the fibres without clogging the interstices - which is what happens in the case of 'closed' waterproofing with fats, paraffin waxes or synthetic resins. These conventional systems have a pronounced tendency to migrate which is increased if the leathers are exposed to thermal or mechanical stress. The result is heavy leathers with a fatty or rubbery surface touch. The new system, on the other hand, imparts a pleasant, more natural and dry touch. The leathers have high water vapour permeability and the waterproofing effect is extremely long-lasting. The dyeing is uniform, with the same colour being obtained on both the grain and flesh sides. Furthermore, the acrylate content of the system facilitates adhesion of the finish. The new technology is also more economical than closed waterproofing - especially as there is no need for additional auxiliaries - and gives good, reproducible results. Italian know-how and many years of experience in leather finishing are combined in LANXESS' X-tra range of products for all types of fashionable leather. The innovative system includes numerous finishing specialities such as waxes, oils, polyurethanes and caseins which can not only be used to achieve the effects required by the latest trends but also give upper leathers with excellent physical fastness properties. The various LANXESS finishing agents can be combined as required to produce the desired surface touch, lustre, weather resistance, light stability and flexibility. With the 20 products available it is possible to obtain all the finishes required in the production of fashionable leather goods, from high-gloss and polishing finishes to a wide range of pull-up effects. The X-tra products are also suitable for use of classical articles such as nappa and box leathers, where they complement the established products and help to make the finished product 'X-tra' special.