Polyol premixes, thermally insulating rigid polyurethane foams and methods for their production
AssigneeCovestro LLC
InventorsBrandon W. Parks, Rick L. Adkins, Laine A. Mosco
Life of this patent
Estimating the term…
Abstract
Polyol premixes and thermally insulating rigid polyurethane foams, such as those that can be used as a thermal insulation medium in the construction of refrigerated storage devices, are disclosed. A polymer polyol having a OH number of at least 200 mg KOH/g and a solids content of at least 40% by weight is utilized. The resulting polyurethane foams can exhibit improved thermal insulation properties without sacrificing other important physical and processing properties.
Claims20
A rigid polyurethane foam comprising the reaction product of a reaction mixture comprising:
- (a) a polyisocyanate;
- (b) a polyol composition comprising a polymer polyol having an OH number of at least 200 mg KOH/g and a solids content of at least 40% by weight, wherein the polymer polyol comprises a reaction product of a reaction mixture comprising:
- (1) a base polyol having a viscosity of no more than 2000 mPa's at 25° C. and an OH number of at least 200 mg KOH/g;
- and
- (2) an ethylenically unsaturated compound;
- (c) a catalyst;
- (d) a physical blowing agent composition comprising at least 50% by weight, based on the total weight of the physical blowing agent composition, of a hydrocarbon;
- and
- (e) a carbon dioxide generating chemical blowing agent;
- wherein the rigid polyurethane foam has a closed-cell content of more than 80 percent, measured according to ASTM D6226-15.
A process for producing a rigid polyurethane foam comprising reacting a polyisocyanate with a polyol premix at an isocyanate index of 90 to 150, wherein the polyol premix comprises:
- (a) a polyol composition comprising a polymer polyol having an OH number of at least 200 mg KOH/g and a solids content of at least 40% by weight, wherein the polymer polyol comprises a reaction product of a reaction mixture comprising:
- (1) a base polyol having a viscosity of no more than 2000 mPa's at 25° C. and an OH number of at least 200 mg KOH/g;
- and
- (2) an ethylenically unsaturated compound;
- (b) a catalyst;
- (c) a physical blowing agent composition comprising at least 50% by weight, based on the total weight of the physical blowing agent composition, of a hydrocarbon;
- and
- (d) a carbon dioxide generating chemical blowing agent.
Dependencies are inferred from the claim text.