RIGID POLYURETHANE FOAMS COMPRISING MODIFIED PHENOLIC RESINS ADDITIVES

1 . A polyurethane or polyisocyanurate foam composition comprising:

a polyol or a mixture thereof;

an isocyanate;

a polyurethane catalyst or a mixture thereof;

a modified phenolic resin, the modified phenolic resin being an oxyalkylated phenolic resin in which at least 30 mol % of phenolic hydroxyl groups have been modified to provide the resin with a primary hydroxyl group, a secondary hydroxyl group, or both; and the composition has an isocyanate index of about 250 or less;

optionally a surfactant;

optionally, a physical blowing agent or a mixture thereof;

optionally, a chemical blowing agent or a mixture thereof; and

optionally, a fire retardant additive or a mixture thereof.

2 . The foam composition of claim 1 , where the modified phenolic resin is a phenolic resin modified with an alkylene oxide, an alkylene carbonate, or a combination of two or more thereof.

3 . The foam composition of claim 1 , where the modified phenolic resin is modified with at least one of ethylene oxide, ethylene carbonate, or a combination thereof

4 . The foam composition of claim 1 , where the modified phenolic resin has less than 50 mol % of free phenolic hydroxyl groups.

5 . The foam composition of claim 1 , where the modified phenolic resin has less than about 25 mol % of free phenolic hydroxyl groups.

6 . The foam composition of claim 1 , where the modified phenolic resin has less than about 10 mol % of free phenolic hydroxyl groups.

7 . The foam composition of claim 1 , wherein at least 50 mol % of the phenolic hydroxyl groups that have been modified to provide primary hydroxyl groups.

8 . The foam composition of claim 1 , wherein about 75 mol % or greater of the phenolic hydroxyl groups that have been modified to provide primary hydroxyl groups.

9 . The foam composition of claim 1 , further comprising the modified phenolic resin in an amount of from about 1 weight percent to about 25 weight percent based on the total weight of the composition excluding the physical blowing agent.

10 . The foam composition of claim 1 , further comprising the modified phenolic resin in an amount of from about 3 weight percent to about 20 weight percent based on the total weight of the composition excluding the physical blowing agent.

11 . The foam composition of claim 1 , where the composition has an isocyanate index of about 200 or less.

12 . The foam composition of claim 1 , where the polyol is selected from a polyester polyols, polyether polyols, polycarbonate polyols, polythioether polyols, polycaprolactones, brominated polyether polyols, acrylic polyols, or a combination of two or more thereof.

13 . The foam composition of claim 1 , where the catalyst is selected from a gelation catalyst, a blowing catalyst, and a trimerization catalyst.

14 . The foam composition of claim 1 comprising (i) a physical blowing agent selected from a pentane isomer, a hydrofluorocarbon, a hydrofluoroolefin, a hydrochlorofluorocarbon, or a combination of two or more thereof; (ii) a chemical blowing agent selected from water, formic acid, or a combination of two or more thereof; or both (i) and (ii).

15 . The foam composition of claim 1 , where the isocyanate composition is selected from an aromatic isocyanate, an aliphatic isocyanate, or any combination thereof

16 . A polyurethane foam formed from the foam composition of claim 1 .

17 . The polyurethane foam of claim 16 , where the foam has an initial thermal conductivity of about 23 mW/m·K or less at a temperature between 10° C. and 36° C.

18 . The polyurethane foam of claim 16 , where the foam has an initial thermal conductivity of about 22 mW/m·K or less at a temperature between 10° C. and 36° C.

19 . An article comprising the polyurethane foam of claim 16 .

20 . A method of forming a polyurethane foam comprising reacting the composition of claim 1 to form a foam.