Patent ID: 11952491
Assignee: DOW TURKIYE KIMYA SANAYI VE TICARET LTD SIRKETI
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A rigid polyurethane foam formulation comprising:
a polyol composition comprising, by weight based on the weight of the polyol composition, from 30% to 70% of a first polyester polyol having a hydroxyl number of from 200 to 250 mg KOH/g, and from 70% to 30% of a second polyester polyol having a hydroxyl number of from 280 to 320 mg KOH/g;
a blowing agent comprising water and an auxiliary blowing agent;
a silicone copolymer surfactant;
from 1% to 5% by weight based on the weight of the polyol composition, of a cyclic siloxane having a surface tension less than 21 dynes/cm at 25° C., wherein the weight ratio of the cyclic siloxane to the silicone copolymer surfactant is from 0.6 to less than 2.27;
a catalyst, and optionally a flame retardant; and
a polyisocyanate;
wherein the isocyanate index is in the range of from 180 to 500.