Polyurethane foams for trench breaker and other applications

Abstract

The invention is directed to polyurethane foams which are flotation resistant with sufficient strength and density to provide stability and inhibit erosion at pipeline trench sites, and other uses, wherein at least 50% of the foam is open cell and has a density of approximately 1.3 lbs/ft 3 to 3.5 lbs/ft 3 . The invention also provides methods for making compositions used to make polyurethane foams that exhibit such characteristics

What is claimed is: 
     
         1 . A reaction mixture which is curable to form a polyurethane foam which is flotation resistant with sufficient strength and density to provide stability and inhibit erosion at pipeline trench sites comprising:
 (a) component A which comprises an isocyanate;   (b) component B which comprises   at least one polyol selected from the group consisting of polyalkoxylated amines, polyalkoxylated ethers, and polyester polyols, wherein all of said at least one polyol make up from 50% by weight to 100% by weight of all polyols in the reaction mixture;   a blowing agent; and   optionally, a cell opening surfactant.   
     
     
         2 . A reaction mixture which is curable to form a polyurethane foam for use in pipeline trench breakers, wherein at least 50% of the foam is open cell and has a density of approximately 1.3 lbs/ft 3  to 3.5 lbs/ft 3 , and has a minimum compressive strength of 17 psi parallel to the rise of the foam, and exhibits a buoyancy loss of at least 20% after 24 hours of testing under 10 feet of water, comprising:
 (a) component A which comprises an isocyanate;   (b) component B which comprises   at least one polyol selected from the group consisting of polyalkoxylated amines, polyalkoxylated ethers, and polyester polyols, wherein all of said at least one polyol make up from 50% by weight to 100% by weight of all polyols in the reaction mixture;   a blowing agent; and   optionally, a cell opening surfactant.   
     
     
         3 . A reaction mixture of  claim 2 , wherein the blowing agent is selected from the group consisting of CFC's, HFC's, HCFC's, HFE's, HFO's, aldols, hydrocarbons and alkyl alkanoates. 
     
     
         4 . A reaction mixture of  claim 2 , wherein the blowing agent makes up about 2% to about 15% by weight of component B. 
     
     
         5 . A reaction mixture of  claim 2 , further comprising water. 
     
     
         6 . A reaction mixture of  claim 2 , wherein the cell opening surfactant makes up about 0.10% to about 4.0% by weight of component B. 
     
     
         7 . A reaction mixture of  claim 2 , wherein the cell opening surfactant is selected from the group consisting of silicones, siloxane copolymers, non-siloxane co-polymers and non-silicones. 
     
     
         8 . A reaction mixture of  claim 2 , wherein the cell opening surfactant makes up about 0.10% to about 1.0% by weight of component B. 
     
     
         9 . A reaction mixture of  claim 2 , wherein the cell opening surfactant makes up about 0.20% to about 0.70% by weight of component B. 
     
     
         10 . A reaction mixture of  claim 2 , further comprising a cell closing surfactant. 
     
     
         11 . A reaction mixture of  claim 10 , wherein the cell closing surfactant makes up about 0.10% to about 4.0% by weight of component B. 
     
     
         12 . A reaction mixture of  claim 10 , wherein the cell closing surfactant makes up about 0.10% to about 4.0% by weight of component B. 
     
     
         13 . A reaction mixture of  claim 10 , wherein the cell closing surfactant is selected from the group consisting of silicones, siloxane copolymers and non-silicones. 
     
     
         14 . A method of producing a polyurethane foam comprising forming a reaction mixture comprising:
 (a) component A which comprises an isocyanate;   (b) component B which comprises   at least one polyol selected from the group consisting of polyalkoxylated amines, polyalkoxylated ethers, and polyester polyols, wherein all of said at least one polyol make up from 50% by weight to 100% by weight of all polyols in the reaction mixture;   a blowing agent; and   optionally, a cell opening surfactant; and curing the reaction mixture to form a rigid, closed-cell polyurethane foam having a density of approximately 1.3 lbs/ft 3  to 3.5 lbs/ft 3 , wherein at least 50% of the foam is open cell, and has a minimum compressive strength of 17 psi parallel to the rise of the foam, and exhibits a buoyancy loss of at least 20% after 24 hours of testing under 10 feet of water.