Yellowing Resistant Leather Finishing Materials

In recent years, the fast development of the automobile industry arouses the development of a series of related industries. Light colored leather, which is always used in the automobile cushion and the inner decoration, is easily yellow-stained. The occurrence may influence its appearance and use. Only resolves the problem, can we improve the quality and the specification.The mechanism and influence factors of the yellow-stain are discussed theoretically in the paper. A series of yellow-stain resistance finishing resins for leathers are studied and prepared. First, fatty aqueous polyurethane finishing latex is prepared, in which alicyclic isocyanate-isophorone diisocyanate(IPDI) and polyester (CMA-654) are the main materials, di-n-butyltin dilaurate (DBTDL) is catalyzer, dimethylolpropanoic acid (DMPA) is hydrophilic salifying substance, diethyleneglycol (DEG) is chain extension agent. The reaction time, temperature, dosage of catalyzer and the synthesis scheme are optimized in the experiment. The influences of the dosage of DMPA and IPDI on polyurethane properties are discussed in detail. Polyester is selected as the synthesizing material of fatty aqueous polyurethane. According to this, the influence of the dosage of chain exptension crosslinking agent (trimethylolpropane(TMP)) on the properties of polyurethane was investigated. The appropriate resins for different coatings for leathers are synthesized. The membrane can reach the criterion of yellow-stain resistance leather finishing materials.Acrylate-modified-polyurethane (PUA) latex is prepared, in which methyl methacrylate (MMA) is rigid monomer, butyl acrylate (BA) is soft monomer. The acrylic ester monomer temperature holding time, the dosage of initiator and the charging system of acrylic ester is optimized separately. The influence of the dosage of acrylic ester monomer, the ratio between soft and rigid acrylic ester monomer, acryl acid, acrylamide, 2-hydroxyethyl acrylate and trimethylolpropane(TMP) on properties of acrylate-modified-polyurethane (PUA) are discussed separately. The nuclear shell...