Low-resilience flexible polyurethane foam and process for producing the same

Abstract

A flexible polyurethane foam whereby exceedingly low resilience can be obtained without using a plasticizer and the hardness change due to a temperature change is little; and a process for its production, are provided. The flexible polyurethane foam is characterized by having a core resilience of 30% or lower and a glass transition point within a range of from −80° C. to −60° C. The process for producing a flexible polyurethane foam comprises reacting a polyol with a polyisocyanate compound in the presence of a catalyst, a foam stabilizer, and a blowing agent, and is characterized by using as the polyol a polyol (1) having a hydroxyl value of from 5 to 15 mgKOH/g.

What is claimed is:  
     
         1 . A flexible polyurethane foam characterized by having a core impact resilience of at most 30% and a glass transition point within a range of from −80° C. to −60° C.  
     
     
         2 . The flexible polyurethane foam according to  claim 1 , which has a hard segment content of at most 40 mass %.  
     
     
         3 . A process for producing a flexible polyurethane foam, which comprises reacting a polyol with a polyisocyanate compound in the presence of a catalyst, a foam stabilizer and a blowing agent, characterized in that as said polyol, a polyol (1) having a hydroxyl value of from 5 to 15 mgKOH/g, is used to produce the flexible polyurethane foam as defined in  claim 1 .  
     
     
         4 . The process for producing a flexible polyurethane foam according to  claim 3 , wherein the polyol (1) is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of an alkylene oxide by means of a double metal cyanide complex catalyst.  
     
     
         5 . The process for producing a flexible polyurethane foam according to  claim 4 , wherein the polyol (1) is a polyoxyalkylene polyol having an oxyalkylene random-chain formed by means of a double metal cyanide complex catalyst.  
     
     
         6 . A flexible polyurethane foam characterized by having a core impact resilience of at most 3% and glass transition points within ranges of from −80° C. to −60° C. and from −20° C. to lower than 0° C.  
     
     
         7 . A process for producing a flexible polyurethane foam, which comprises reacting a polyol with a polyisocyanate compound in the presence of a catalyst, a foam stabilizer and a blowing agent, characterized in that as said polyol, a polyol mixture is used which comprises a polyol (1) having a hydroxyl value of from 5 to 15 mgKOH/g and a polyol (2) having a hydroxyl value of from 40 to 250 mgKOH/g and a number of functional groups of from 2 to 4, to produce the flexible polyurethane foam according to  claim 6 .  
     
     
         8 . The process for producing a flexible polyurethane foam according to  claim 7 , wherein the polyol (1) is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of an alkylene oxide by means of a double metal cyanide complex catalyst.  
     
     
         9 . The process for producing a flexible polyurethane foam according to  claim 8 , wherein the polyol (1) is a polyoxyalkylene polyol having an oxyalkylene random-chain formed by means of a double metal cyanide complex catalyst.  
     
     
         10 . The process for producing a flexible polyurethane foam according to  claim 7 , wherein the mixed mass ratio of the polyol (1) to the polyol (2) in the above polyol mixture is (1):(2)=50:50 to 75:25.