Methyltin catalysts for polyesterfication
OwnerNeal Douglas Conrad, Paul Mercandoinventors
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Abstract
Methyltin compounds useful as catalysts in high-temperature esterification and polyesterification reactions are described. The esters and polyesters produced by the process possess superior physical/chemical properties such as improved color and thermal stability with less production of undesirable by-products. The greater stability of these catalysts allows their use in multistage polyesterification reactions and leads to lower use levels in some cases.
Claims19
An improved process for producing polyesters comprising combining polyester forming reactants with a catalytically effective amount of a methyl tin catalyst and wherein said reactants includes a polyol and less than 50 mole % of said polyol is 1,4 butane diol and less than 50 mole % of said polyol is a secondary hydroxyl containing polyol.
The improved process of claim lwherein a butyl tin catalyst is used in combination with the methyl tin catalyst.
Dependencies are inferred from the claim text.