Liquid terephthalic ester polyols and polyisocyanurate foams therefrom
AssigneeTexaco Inc.
InventorsRobert A. Grigsby, Jr., George P. Speranza, Michael E. Brennan
Life of this patent
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Abstract
Terephthalic esters may be made to remain in a liquid form by reacting recycled or scrap polyethylene terephthalate (PET) with diethylene glycol and one or more oxyalkylene glycols and stripping out some of the ethylene glycol present. The mole ratio of glycols to scrap PET should also be greater than 1.2:1. This process keeps any diesters from separating out of the solution as solids. These liquid terephthalic esters are useful as polyol extenders in rigid polyurethane foams and as the sole polyol component in polyisocyanurate foams.
Claims17
A mixture of liquid terephthalic ester polyols produced by the process comprising
- a. reacting recycled polyethylene terephthalate with diethylene glycol and at least one more oxyalkylene glycol, where the mole ratio of glycols to recycled polyethylene terephthalate is greater than 1.2:1, and
- b. stripping off as overhead at least 5 wt.% of the reaction product from step a. based on the reactants charged, where at least 25% of the overhead is ethylene glycol, to give a mixture of esters which is free from solids upon standing.
A mixture of liquid terephthalic ester polyols produced by the process comprising
- a. reacting recycled polyethylene terephthalate with diethylene glycol and at least one more oxyalkylene glycol, selected from the group of glycols having the formula ##STR4## where R is hydrogen or lower alkyl of 1 to 4 carbon atoms and n is from 2 to 4, where the mole ratio of glycols to recycled polyethylene terephthalate is greater than 1.2:1, and
- b. stripping at least 5 wt.%, based on the reactants charged, as overhead where at least 25 wt.% of the overhead is ethylene glycol, to give a mixture of esters which is free from solids upon standing having a hydroxyl number between 100 and 500.
A process for the production of a mixture of liquid terephthalic ester polyols comprising
- a. reacting recycled polyethylene terephthalate with diethylene glycol and at least one more oxyalkylene glycol, where the mole ratio of glycols to recycled polyethylene terephthalate is greater than 1.2:1, and
- b. stripping off as overhead at least 5 wt.% of the reaction product from step a. based on the reactants charged, where at least 25 wt.% of the overhead is ethylene glycol, to give a mixture of esters which is free from solids upon standing.
Dependencies are inferred from the claim text.