Method of molding rigid polyurethane foams with enhanced thermal conductivity
First Claim
1. A process for producing a rigid polyurethane foam having a molded density of 33 to 38 kg/m3 and Lambda(10°
- C.) of less than 21 mW/m.K and a ratio of molded foam density (kg/m3) to Lambda(10°
C.) (mW/m.K), measured 24 hours after foam production, from 1.65 to 2.15, obtained by injecting into a closed mold cavity a reaction mixture at a packing factor of 1.03 to 1.9 wherein the mold cavity has a reduced pressure of 300 to 950 mbar and the reaction mixture comprises;
A) an organic polyisocyanate;
B) a physical blowing agent present in an amount from 10 to 30 weight percent of the polyol composition wherein the blowing agent is a hydrocarbon selected from n-pentane, iso-pentane, cyclopentane, n-butane, cyclohexane or a mixture thereof,C) a polyol composition containing at least one polyol with a functionality of 3 or greater and a hydroxyl number between 300 and 800D) water present at 0.1 to 2.5 weight percent of the total polyol formulation;
E) catalyst andF) auxiliary substances and/or additives.
6 Assignments
0 Petitions
Accused Products
Abstract
The present invention is to a molded rigid polyurethane foam for application in appliance, having a reduced thermal conductivity at densities between 33 and 38 kg/m3 and a process for the production of such foams. The molded rigid polyurethane foam have a ratio of applied foam density (kg/m3) to lambda (mW/mK), measured at 10° C., 24 hours after foam production from 1.65 and to 2.15 and are obtained by the process of injecting into a closed mold cavity under reduced pressure a reaction mixture at a packing factor of 1.1 to 1.9 and the reaction mixture comprises: A) an organic polyisocyanate; B) a physical blowing agent, C) a polyol composition containing at least one polyol with a functionality of 3 or greater and a hydroxyl number between 200 and 800 and a water content of 0 to 2.5 weight percent of the total polyol composition; D) catalyst and E) auxiliary substances and/or additives.
8 Citations
14 Claims
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1. A process for producing a rigid polyurethane foam having a molded density of 33 to 38 kg/m3 and Lambda(10°
- C.) of less than 21 mW/m.K and a ratio of molded foam density (kg/m3) to Lambda(10°
C.) (mW/m.K), measured 24 hours after foam production, from 1.65 to 2.15, obtained by injecting into a closed mold cavity a reaction mixture at a packing factor of 1.03 to 1.9 wherein the mold cavity has a reduced pressure of 300 to 950 mbar and the reaction mixture comprises;A) an organic polyisocyanate; B) a physical blowing agent present in an amount from 10 to 30 weight percent of the polyol composition wherein the blowing agent is a hydrocarbon selected from n-pentane, iso-pentane, cyclopentane, n-butane, cyclohexane or a mixture thereof, C) a polyol composition containing at least one polyol with a functionality of 3 or greater and a hydroxyl number between 300 and 800 D) water present at 0.1 to 2.5 weight percent of the total polyol formulation; E) catalyst and F) auxiliary substances and/or additives. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- C.) of less than 21 mW/m.K and a ratio of molded foam density (kg/m3) to Lambda(10°
Specification