LEAD-FREE STABILIZATION FOR PVC PIPES: THE NEW ALTERNATIVE

摘要

PVC remains the material of choice for the construction industry and pipe producers. However, environmental concern and regulations will lead to the elimination of lead based heat stabilizers over the next five years. This move to lead free stabilizers will cause pipe producers to re-evaluate their stabilizer options as they strive to keep the cost competitiveness of their PVC formulations. Thus, the challenge for stabilizer manufacturers is to propose new lead-free stabilizers for pipes with good performance and attractive costs.Rohm and Haas Company has developed a new Lead Free System (LFS) that is based on a derivative of the mercaptan chemistry which has been used for decades with conventional tin stabilizers. The patented "Latent Mercaptan" technology includes organic based, heavy metal free compositions that contain blocked thiols, which under vinyl processing conditions, generate highly active stabilizing components.These innovative LFS systems offer wide processing windows, give excellent early color, and can be adjusted to meet the various technical requirements of the pipe market. The LFS systems are odor free, and are compatible with all standard stabilizer systems. Additional benefits include reduced cross-linking leading to easier recycling. The LFS systems are non toxic, contain no heavy metals, and are available as stabilizer system additives or as one-packs, offering excellent price/performance ratio.Here we present information detailing the LFS stabilization mechanism and performance attributes (stabilization, rheology, and recycling data) on laboratory and industrial equipment.