| 摘要 |
<p>A storage stable polyester polyol mixture is prepared by digesting polyalkylene terephthalate, particularly polyethylene terephthalate, with a digesting medium comprising a polycarboxylic acid component-containing polyol, wherein the polycarboxylic acid component has ring units with two <IMAGE> groups on adjacent or alternate ring positions, the ring unit content of the polycarboxylic acid component being sufficient for improved storage stability of the digestion product. The polyester polyol mixture is useful in the preparation of cellular foam materials, particularly polyisocyanurate and polyurethane foams.</p> |
