Poly(urethane-isocyanurate) foams
AssigneeMinnesota Mining and Manufacturing Company
InventorEdward W. Janssen
Life of this patent
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Abstract
Novel poly(urethane-isocyanurate) foams and their preparation are described. These foams are low density, non-friable, heat stable, polymeric reaction products of polyisocyanate and polyoxyalkylene polyol, the reaction products having a cross-link density in the range of about 1 cross-link per 400 to 750 atomic weight units. Processes are also provided for forming a foamed isocyanate-derived polymer on an oil-contaminated substrate and obtaining a firm bond of the polymer to the substrate.
Claims8
A low density, non-friable, foamed polymeric reaction product formed by the reaction of organic polyisocycanate and polyoxyalkylene polyol in the presence of isocyanate trimerization catalyst, water as the blowing agent and surfactant, the NCO/OH equivalent ratio being 1.3/1 to 3/1, wherein more than half of th oxyalkylene units of said polyol are oxypropylene units and wherein the average molecular weight of said polyol is in the range of 700 to 1,500;
- said polymeric reaction product having isocyanate-derived linkages selected from the group consisting essentially of isocyanurate, uethane and urea linkages;
- the crosslink density of said product being in the range of about one crosslink per 400 to 600 atomic weight units, and wherein said polymeric reaction product exhibits a beam flexure characteristic of at least 100 pounds with at least one inch deflection.
A composition which, when mixed with organic polyisocyanate, reacts to form a foamed polymeric reaction product, said composition comprising:
- (a) polyoxyalkylene polyol, wherein at least half of the oxyalkylene unit of said polyol are oxypropylene units, and wherein the average molecular weight of said polyol is in the range of 700 to 1,500;
- (b) isocyanate trimerization catalyst;
- (c) water as the blowing agent;
- (d) foam stabilizer of the formula;
- (R.sub.f).sub.m Q.sub.z (H).sub.n wherein R.sub.f is a fluorinated, saturated aliphatic radical, H is an active hydrogen atom, Q is a linkage free of active hydrogen atoms and having a valence of m+n, m is an integer which is at least 1, n is an integer of at least 2, and z is an integer of 1-3;
- wherein said composition, when mixed with an amount of organic polyisocyanate sufficient to form a mixture wherein the NCO/OH equivalent ratio is in the range of 1.3/1 to 3/1, reacts to form a tough, non-friable foamed polymeric reaction product having a crosslink density of about one crosslink per 400 to 600 atomic weight units.
A low density, non-friable, heat-stable foamed polymeric reaction product formed by the reaction of organic polyisocyanate and polyoxyalkylene polyol in the presence of isocyanate trimerization catalyst, water as the blowing agent and surfactant, the NCO/OH equivalent ratio being about 1.3/1 to about 1.5/1, wherein more than half of the oxyalkylene units of said polyol are oxypropylene units and wherein the average molecular weight of said polyol is in the range of about 1,000 to about 1,500;
- said polymeric reaction product having isocyanate-derived linkages selected from the group consisting essentially of isocyanurate, urethane and urea linkages;
- the crosslink density of said product being in the range of about one cross-link per 400 to 600 atomic weight units, and wherein said polymeric reaction product exhibits a beam flexure characteristic of at least 100 pounds with at least one inch deflection.
Dependencies are inferred from the claim text.