公开(公告)号：US5473102A

公开(公告)日：1995-12-05

申请号：US318228

申请日：1994-10-05

申请人： Floyd Johnson ,  David L. Sikkenga ,  Kalpana Danawala ,  Bruce I. Rosen

发明人： Floyd Johnson ,  David L. Sikkenga ,  Kalpana Danawala ,  Bruce I. Rosen

IPC分类号： C07C51/09 ,  C07C67/60

CPC分类号： C07C51/09

摘要： Processes are disclosed for recovery and purification of dibasic aromatic acids from waste polyester film, fiber, bottles, manufacturing residues, and other manufactured articles. The processes comprises: depolymerization of polyester resin in a molten polyester resin containing solvent with superheated stem, and vaporization of the aromatic carboxylic acid and other volatile products of hydrolysis to obtain a vaporized mixture containing aromatic acid, dihydric alcohol, other volatile products of hydrolysis, and water. This vapor mixture is, advantageously, substantially free of less volatile and non-volatile impurities including metals, and many colored and color causing compounds, which are, typically, found in post-consumer polyester resins.Crude acid is, optionally, purified by hydrogenated in an aqueous solution at elevated temperatures and pressures in the presence of hydrogen and an insoluble metal-containing catalyst, which is thereupon separated from the aqueous solution, and purified dibasic aromatic acid recovered by crystallization and mechanical separation from the aqueous solution. Purified terephthalic acid has, typically, a L*-value in a rage of from about 95 to about 100, an a*-value in a rage of from about -1 to about +1, and a b*-value in a range of from about 0.5 to about 2.

摘要翻译： 公开了用于从废聚酯膜，纤维，瓶，制造残余物和其它制品中回收和纯化二元芳香酸的方法。 该方法包括：将聚酯树脂在含有过热干燥的溶剂的熔融聚酯树脂中解聚，并将芳族羧酸和其它挥发性水解产物汽化，得到含有芳族酸，二元醇，水解的其它挥发性产物的蒸发混合物， 和水。 这种蒸气混合物有利地基本上不含挥发性和非挥发性的杂质，包括金属，以及通常在消费后聚酯树脂中发现的许多着色和着色的化合物。 任选地，在氢气和不溶性金属的催化剂存在下，在高温和高压下，在水溶液中氢化，然后与水溶液分离，纯化纯酸，通过结晶和机械回收的纯化的二元芳香酸 与水溶液分离。 纯化的对苯二甲酸通常具有约95至约100的浓度的L *值，在约-1至约+1的范围内的a *值和在一定范围内的ab * 约0.5至约2。