| abstract |
A process for producing a polyurethane or polyisocyanurate construction board, the process comprising (i) providing an A-side reactant stream that includes an isocyanate containing compound; (ii) providing a B-side reactant stream that includes a polyol and a physical blowing agent, where the physical blowing agent includes pentane, butane, and optionally a blowing agent additive that has a Hansen Solubility Parameter (δt) that is greater than 17 MPa-0.5; and (iii) mixing the A-side reactant stream with the B-side reactant stream to produce a reaction mixture. |