초록 ▼

Rigid polyurethane foam is produced from polyisocyanate and polyol wherein 5-30% by weight of the polyol ingredient is a digestion product of polyalkylene terephthalate residues or scraps digested with organic polyols. The resulting rigid polyurethane foam exhibits uniform density and, when compared

Rigid polyurethane foam is produced from polyisocyanate and polyol wherein 5-30% by weight of the polyol ingredient is a digestion product of polyalkylene terephthalate residues or scraps digested with organic polyols. The resulting rigid polyurethane foam exhibits uniform density and, when compared with a corresponding polyurethane foam which does not include the said digestion products, exhibits equivalent or superior physical strength properties. With fire retardant rigid polyurethane foams wherein the organic polyol ingredient includes halogenated organic polyols, use of 5-30% by weight of the said digestion product in the organic polyol ingredient, achieves a rigid fire retardant polyurethane foam having a lower flame spread and a lower smoke generation than a corresponding polyurethane foam which does not include the said digestion product. When fabricated in a closed mold, the present rigid polyurethane foam has a more uniform density, i.e., a higher core density, than corresponding rigid polyurethane foams which do not include the said digestion product.

대표청구항 ▼

A method for making rigid polyurethane foam which comprises combining (a) an organic polyisocyanate; (b) an organic polyol; (c) a halogenated alkane blowing agent; (d) a surfactant; (e) a catalyst for the reaction of －OH and －NCO radicals; wherein from 5 to 30 percent of the weight of the said organ

A method for making rigid polyurethane foam which comprises combining (a) an organic polyisocyanate; (b) an organic polyol; (c) a halogenated alkane blowing agent; (d) a surfactant; (e) a catalyst for the reaction of －OH and －NCO radicals; wherein from 5 to 30 percent of the weight of the said organic polyol is a digestion product obtained by digesting polyalkylene terephthalate having a molecular weight greater than 15,000 in a reactive solvent selected from the class consisting of organic diols and triols having a molecular weight from 62 to 500 until the digestion product is soluble in acetone at room temperature; and recovering a resulting rigid polyurethane foam which has a lower overall density than a corresponding polyurethane foam made from the same ingredients except for the said digestion product and which foam exhibits equivalent or superior shear strength and compressive strength when compared to the corresponding rigid polyurethane foam of the same overall density made from the same ingredients except for the said digestion product.