Method for preparing polyurethanes using 3,9-bis(2-hydrazidoethyl)-2-4,8,10-tetraoxaspiro-[5,5]-undecane as chain extender
AssigneeBridgestone Tire Company Limited
InventorsToshio Yukuta, Takashi Ohashi
Life of this patent
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Abstract
Polyurethane is prepared by reacting a prepolymer having terminal isocyanate groups with 3,9-bis(2-hydrazidoethyl)-2,4,8,10-tetraoxaspiro-[5,5]-undecane.
Claims9
A method for preparing polyurethane which comprises reacting 3,9-bis(2-hydrazidoethyl)-2,4,8,10-tetraoxaspiro-[5,5]-undecane as a chain extender with a prepolymer having terminal isocyanate groups produced by reacting an organic polyisocyanate with hydroxyl-containing compound having a number average molecular weight ranging from 400 to 5000, the equivalent ratio of the active hydrogen of the chain extender to the isocyanate group of the prepolymer ranging from 0.8 to 1.3.
A method for preparing polyurethane which comprises reacting 3,9-bis(2-hydrazidoethyl)-2,4,8,10-tetraoxaspiro-[5,5]-undecane as a chain extender with a prepolymer having terminal isocyanate groups produced by reacting an organic polyisocyanate selected from a class of tolylene -2,4 and 2,6-diisocyanates, 4,4'-diphenyl methane diisocyanate, xylylene diisocyanate, hydrogenated 4,4'-diphenyl methane diisocyanate, hexamethylene-1,6-diisocyanate and the mixture thereof with a hydroxyl-containing compound having a number average molecular weight ranging from 400 to 5000 selected from a class of polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol and polyethylene adipate glycol, and the equivalent ratio of the active hydrogen of the chain extender to the isocyanate group of the prepolymer ranging from 0.80 to 1.30.
Dependencies are inferred from the claim text.