Diol-terminated polycarbonates
AssigneeEnichem Synthesis S.p.A.
InventorAlberto Greco
Life of this patent
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Abstract
Diol-polycarbonates having the general formula HO--(Ri--O--CO--O).sub.x ----(R.sub.2 --O--CO--O--).sub.y --R.sub.3 --OH (I) where R.sub.1, R.sub.2, R.sub.3, X and Y have the meaning specified in the text, are used in the synthesis of prepolymers which in turn can be used in reactive adhesive and/or sealing formulations of the hygro-, photo- or thermosetting type, and the procedure for their preparation. The sealing compositions deriving from these diolterminated-polycarbonates are mainly used in transport industry, in the textile and wood industry, for cellular products and in the bookbinding industry.
Claims11
A diol-terminated polycarbonate having the formula (I):
- HO--(R.sub.1 --O--CO--O).sub.x --(R.sub.2 --O--CO--O).sub.y --R.sub.3 OH
- wherein the succession of radicals
- --R.sub.1 --O--CO--O-- and --R.sub.2 --O--CO--O--
- inside the copolymer is purely random;
- R.sub.1 is a polymethylene radical containing from 9 to 12 carbon atoms, or combinations thereof;
- R.sub.2 is a bivalent radical derived by the loss of the two hydroxyl groups from a diol selected from the group consisting of 1,4-butandiol, 2,2-dimethyl-1,3-propandiol, 1,5-pentandiol, 1,6-hexandiol, 1,4bishydroxymethylcyclohexane, triethyleneglycol and the diol derived by the condensation of caprolactone with 1,6l -hexandiol;
- R.sub.3 is a bivalent radical which is R.sub.1 or R.sub.2, and x and y have such values that:
- (a) the fraction of the structural units corresponding to:
- --(R.sub.1 --OCO--O).sub.x -- is from 50 to 95% by weight of the entire copolymer;
- and
- (b) the number molecular weight (MW) of the polycarbonate diol having formula (I) ranges from 1500 to 15,000.
Dependencies are inferred from the claim text.