Isocyanate-reactive compositions, rigid polyurethane foams and methods for their production
Isocyanate-reactive compositions 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. The compositions include a halogenated olefin blowing agent and a polymer polyol. The polymer polyol includes (1) a base polyol having an OH number of at least 200 mg KOH/g; and (2) polymer particles dispersed in the base polymer, wherein the polymer particles comprise the reaction product of an ethylenically unsaturated composition comprising an ethylenically unsaturated fluorinated compound.
1 . An isocyanate-reactive composition comprising:
(a) a polyol composition comprising a polymer polyol having an OH number of greater than 200 mg KOH/g, wherein the polymer polyol comprises:
(1) a base polyol having an OH number of at least 200 mg KOH/g; and
(2) polymer particles dispersed in the base polyol, wherein the polymer particles comprise the reaction product of an ethylenically unsaturated composition comprising an ethylenically unsaturated fluorinated 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 halogenated olefin; and
(d) a carbon dioxide generating chemical blowing agent.
2 . The isocyanate-reactive composition of claim 1 , wherein the base polyol having an OH number of at least 200 mg KOH/g comprises a polyether polyol having a functionality of 2 to 6 and an OH number of at least 300 mg KOH/g that is present in an amount of at least 50% by weight, based on total weight of base polyol in the polymer polyol.
3 . The isocyanate-reactive composition of claim 1 , wherein the base polyol having an OH number of at least 200 mg KOH/g is derived from an alkylene oxide in which the content of ethylene oxide units in the base polyol, based on the total weight of the base polyol, is no more than 10% by weight.
4 . The isocyanate-reactive composition of claim 1 , wherein the ethylenically unsaturated fluorinated compound has (i) the structure:
in which R 1 is H or CH 3 , R 2 is a fluorine-free divalent linking group, and R 3 is a C 1-18 polyfluoroalkyl group, or (ii) the structure:
in which R 4 is a fluorine-free divalent linking group, and R 5 is a C 1-18 polyfluoroalkyl group
wherein the ethylenically unsaturated fluorinated compound is present in an amount of 10 to 25% by weight, based on total weight of the ethylenically unsaturated composition, and
wherein the ethylenically unsaturated composition further comprises styrene and acrylonitrile, wherein the weight ratio of styrene to acrylonitrile is 80:20 to 20:80.
5 . The isocyanate-reactive composition of claim 1 , wherein the polymer polyol has an OH number of at least 240 mg KOH/g.
6 . The isocyanate-reactive composition of claim 1 , wherein the polymer polyol is present in an amount of at least 10% by weight, based on the total weight of the polyol composition.
7 . The isocyanate-reactive composition of claim 1 , wherein the polyol composition further comprises an aromatic amine-initiated polyether polyol having a functionality of 2 to 6 and a hydroxyl number of 300 to 500 mg KOH/g, wherein the aromatic-amine initiated polyether polyol is present in an amount of 20 to 60% by weight, based on the total weight of the polyol composition.
8 . The isocyanate-reactive composition of claim 7 , wherein the polyol composition comprises an aromatic polyester polyol having an OH number of 150 to 410 mg KOH/g and a functionality of 1.5 to 3, wherein the aromatic polyester polyol is present in an amount of 10 to 40% by weight, based upon the total weight of the polyol composition.
9 . The isocyanate-reactive composition of claim 1 , wherein the halogenated olefin comprises 1-chloro-3,3,3-trifluoropropene present in an amount of 10 to 30% by weight, based on the total weight of the isocyanate-reactive composition and wherein the 1-chloro-3,3,3-trifluoropropene is present in an amount of at least at least 90% by weight, based on the total weight of the physical blowing agent composition.
10 . A process for producing a rigid polyurethane foam comprising mixing a polyisocyanate with the isocyanate-reactive composition of claim 1 at an isocyanate index of 90 to 150.
11 . The isocyanate-reactive composition of claim 1 , wherein the halogenated olefin is present in an amount of at least 70% by weight, based on total weight of the physical blowing agent composition.
12 . The isocyanate-reactive composition of claim 1 , wherein the halogenated olefin is present in an amount of at least 80% by weight, based on total weight of the physical blowing agent composition.
13 . The isocyanate-reactive composition of claim 1 , wherein the halogenated olefin is present in an amount of at least 90% by weight, based on total weight of the physical blowing agent composition.
14 . The isocyanate-reactive composition of claim 1 , wherein the halogenated olefin is present in an amount of at least 95% by weight, based on total weight of the physical blowing agent composition.
15 . The isocyanate-reactive composition of claim 1 , wherein the isocyanate-reactive composition is substantially free of hydrocarbon blowing agent.