Latent mercaptans as multi-functional additives for halogen-containing polymer compositions
申请人:——
公开号:US20030216493A1
公开(公告)日:2003-11-20
Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan. The latent mercaptans also serve as intermediates in the preparation of anti-oxidants, anti-microbial agents, photostabilizers, and primary heat stabilizers. Highly effective heat stabilizers are prepared by the condensation of formaldehyde and a para-phenol and further condensation of the crude product with a mercapto-containing compound.
含卤素聚合物组合物包括一种潜在的巯基含量热稳定剂组合物,该组合物基本上不含有通常与巯基相关联的刺激性气味,在加工过程中通过潜在(即被阻断的)巯基的降解产物(包括自由巯基)来保护。降解的其他产物被认为包括阻断基的碳正离子,其通过电子亏损由几个基团共享的分子结构稳定。潜在巯基可以是唯一的热稳定剂添加剂,但在加工过程中释放的自由巯基也可以协同作用于金属基热稳定剂,如金属盐和有机金属稳定剂,如有机锡羧酸盐和巯基化合物在聚合物组合物中的活性。通过少量潜在巯基掩盖含有主要巯基热稳定剂的卤化聚合物组合物的气味。潜在巯基还可用作抗氧化剂、抗微生物剂、光稳定剂和主要热稳定剂的制备中间体。通过甲醛和对苯酚的缩合,并将粗产品与含巯基的化合物进一步缩合,可以制备高效的热稳定剂。