Storage-stable polyol compositions for producing rigid polyisocyanurate foam
AssigneeDow Global Technologies LLC
InventorsPaolo Golini, Francesca Pignagnoli
Life of this patent
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Abstract
Disclosed is a polyol composition comprising an aliphatic polyester polyol having a hydroxyl value of less than about 100 and prepared by the reaction of at least a polycarboxylic acid with a polyhydroxy compound; an aromatic polyester polyol; a Novolac-type polyether polyol; and a hydrofluorocarbon blowing agent; that may be storage-stable for at least 60 days. This composition may be reacted with a polyisocyanate at an isocyanate index of from about 2.5 to about 4 to form a rigid poly-isocyanurate foam. The foam shows improved cohesion in general and also improved adhesion and a reduced incidence of voids when applied to a metal substrate.
Claims19
A storage-stable polyol composition consisting essentially of
- (a) from about 1 to about 20 percent by weight of an aliphatic polyester polyol having a hydroxyl number of less than about 100, wherein the aliphatic polyester polyol is prepared by the reaction of at least a polycarboxylic acid, or an anhydride of the polycaroxylic acid, with a polyhydroxy compound;
- (b) from about 1 to about 60 percent by weight of an aromatic polyester polyol;
- (c) from about 1 to about 60 percent by weight of a Novolac-type polyether polyol;
- and
- (d) from about 1 to about 20 percent by weight of a hydrofluorocarbon blowing agent;
- wherein the weight percent ratio of aromatic polyester polyol to aliphatic polyester polyol is from about 80:20 to about 30:70 and the polyol composition does not exhibit phase separation, as determined by unenhanced visual inspection, for a period of at least 60 days under ambient conditions.
A formulation for preparing a polyisocyanurate foam comprising
- a polyisocyanate;
- and
- a polyol composition comprising
- (a) from about 1 to about 20 percent by weight of an aliphatic polyester polyol having a hydroxyl number of less than about 100, wherein the aliphatic polyester polyol is prepared by the reaction of at least a polycarboxylic acid with a polyhydroxy compound;
- (b) from about 1 to about 60 percent by weight of an aromatic polyester polyol;
- (c) from about 1 to about 60 percent by weight of a Novolac-type polyether polyol;
- and
- (d) from about 1 to about 20 percent by weight of a hydrofluorocarbon blowing agent;
- the polyol composition being such that it does not exhibit phase separation, as determined by unenhanced visual inspection, for a period of at least 60 days under ambient conditions.
A method of preparing a polyisocyanurate foam comprising contacting under foam-forming conditions
- a polyisocyanate;
- and
- a polyol composition comprising
- (a) from about 1 to about 20 percent by weight of an aliphatic polyester polyol having a hydroxyl number of less than about 100, wherein the aliphatic polyester polyol is prepared by the reaction of at least a polycarboxylic acid with a polyhydroxy compound;
- (b) from about 1 to about 60 percent by weight of an aromatic polyester polyol;
- (c) from about 1 to about 60 percent by weight of a Novolac-type polyether polyol;
- the polyol composition being such that it does not exhibit phase separation, as determined by unenhanced visual inspection, for a period of at least 60 days under ambient conditions;
- and
- (d) from about 1 to about 20 percent by weight of a hydrofluorocarbon blowing agent;
- wherein the weight percent ratio of aromatic polyester polyol(s) to aliphatic polyester polyol(s) is from about 80:20 to about 30:70, the polyol composition being such that it does not exhibit phase separation, as determined by unenhanced visual inspection, for a period of at least 60 days under ambient conditions;
- at an isocyanate index ranging from about 2.5 to about 4;
- to form a rigid polyisocyanurate foam.
Dependencies are inferred from the claim text.