Acoustical insulating foam from compatibilized blends of poly (vinyl aromatic) polymers and poly (alpha -olefin) polymers

Abstract

Foams made from a ternary blend of a alkenyl aromatic polymer such as polystyrene, an α-olefin polymer such as polyethylene, and a compatibilizer, are used as acoustical insulation in building constructions. These foams exhibit an unusual combination of low creep and low dynamic stiffness. They are especially useful in floating floor installations.

What is claimed is:  
     
         1 . An improvement in a building construction wherein acoustical insulation is installed in a wall, ceiling or floor of said building construction, the improvement wherein said acoustical insulation is a foam of a polymer blend including (a) at least one alkenyl aromatic polymer, (b) at least one α-olefin polymer and (c) an effective amount of a compatibilizer for said alkenyl aromatic polymer and said α-olefin polymer at the relative proportions thereof that are present in said polymer blend.  
     
     
         2 . The improved building construction of  claim 1 , wherein said foam has a dynamic modulus of no greater than about 1,500 kN/m 2  at a thickness of 3-20 mm.  
     
     
         3 . The improved building construction of  claim 1 , wherein said foam has a density of about 10 to about 70 kg/m 3  and an open cell content of from about 15 to 95%.  
     
     
         4 . The improved building construction of  claim 1 , wherein said foam has a dynamic modulus of no greater than about 800 kN/m 2  at a thickness of 3-20 mm.  
     
     
         5 . The improved building construction of  claim 1 , wherein said compatibilizer includes a substantially random interpolymer containing, in polymerized form, 
 (1) from 1 to 65 mol percent of repeating units derived from; 
 (a) at least one vinyl or vinylidene aromatic monomer, or  
 (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or  
 (c) a mixture of (a) and (b);  
   (2) from 35 to 99 mol percent of repeating units derived from ethylene and/or a C 3-20  α-olefin; and    (3) no more than 20 mol percent of repeating units derived from ethylenically unsaturated polymerizable monomers other than (1) and (2).    
     
     
         6 . The improved building construction of  claim 1 , wherein said polymer blend contains from about 25 to about 75% by weight of alkenyl aromatic polymer, about 20 to about 50% by weight of α-olefin polymer and about 2 to about 50% by weight of said compatibilizer, all said percentages being based on the combined weight of the alkenyl aromatic polymer, α-olefin polymer and compatibilizer.  
     
     
         7 . An improvement in a building construction wherein acoustical insulation is installed in a wall, ceiling or floor of said building construction, the improvement wherein said acoustical insulation is a foam of a polymer blend including (a) about 25 to about 75% by weight polystyrene, (b) about 25 to about 50% by weight polyethylene or a copolymer of ethylene and up to about 15 mole-percent of another α-olefin and (c) about 2 to about 50% by weight of a substantially random interpolymer having a melt flow index (190° C./2.16 kg) of 0.1 to 50 g/10 min, and an M w /M n  of 1.5 to 20; which contains, in polymerized form; 
 (1) from 3 to 55 mol percent of polymer units derived from; 
 (a) at least one vinyl or vinylidene aromatic monomer, or  
 (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or  
 (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and  
 
 (2) from 45 to 97 mol percent of repeating units derived from ethylene and/or a C 3-20  α-olefin; and  
 (3) no more than 20 mol percent of repeating units derived from one or more of ethylenically unsaturated polymerizable monomers other than (1) and (2) the % by weight of each of components (a), (b) and (c) being based on the total weight of components (a), (b) and (c).  
 
     
     
         8 . An improvement in a building construction wherein acoustical insulation is installed in a wall, ceiling or floor of said building construction, the improvement wherein said acoustical insulation is a foam of a polymer blend including (a) about 25 to about 75% by weight polystyrene, (b) about 25 to about 50% by weight polyethylene or a copolymer of ethylene and up to about 15 mole-percent of another α-olefin and (c) about 2 to about 50% by weight of a hydrogenated block copolymer of a monovinylidene aromatic monomer and a conjugated diene, the % by weight of each of components (a), (b) and (c) being based on the total weight of components (a), (b) and (c).  
     
     
         9 . An improvement in a building construction wherein acoustical insulation is installed in a wall, ceiling or floor of said building construction, the improvement wherein said acoustical insulation is a foam of a polymer blend including (a) about 25 to about 75% by weight polystyrene, (b) about 25 to about 50% by weight polyethylene or a copolymer of ethylene and up to about 15 mole-percent of another α-olefin and (c) about 2 to about 50% by weight of a block copolymer of styrene and ethylene, the% by weight of each of components (a), (b) and (c) being based on the total weight of components (a), (b) and (c).  
     
     
         10 . An improvement in floating flooring systems comprising a structural subfloor, a floating floor overlaid over said subfloor, and a layer of acoustical insulation installed between said structural subfloor and said floating floor, the improvement wherein said acoustical insulation is a foam of a polymer blend including (a) at least one alkenyl aromatic polymer, (b) at least one α-olefin polymer and (c) an effective amount of a compatibilizer for said alkenyl aromatic polymer and said α-olefin polymer at the relative proportions thereof that are present in said polymer blend.  
     
     
         11 . The improvement of  claim 10 , wherein said foam has a dynamic modulus of no greater than about 600,000 N/m 2  at a thickness of 3-20 mm.  
     
     
         12 . The improvement of  claim 10 , wherein said foam has a density of about 10 to about 70 kg/m 3  and an open cell content of from about 15 to 95%.  
     
     
         13 . The improvement of  claim 10 , wherein said foam has a dynamic modulus of no greater than about 450,000 N/m 2  at a thickness of 3-20 mm.  
     
     
         14 . The improvement of  claim 10 , wherein said compatibilizer includes a substantially random interpolymer containing, in polymerized form, 
 (1) from 1 to 65 mol percent of repeating units derived from; 
 (a) at least one vinyl or vinylidene aromatic monomer, or  
 (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or  
 (c) a mixture of (a) and (b);  
   (2) from 35 to 99 mol percent of repeating units derived from ethylene and/or a C 3-20  α-olefin; and    (3) no more than 20 mol percent of repeating units derived from ethylenically unsaturated polymerizable monomers other than (1) and (2).    
     
     
         15 . The improvement of  claim 10 , wherein said polymer blend contains from about 25 to about 75% by weight of alkenyl aromatic polymer, from about 20 to about 50% by weight of α-olefin polymer, and from about 2 to about 50% by weight of said compatibilizer, all said percentages being based on the combined weight of the alkenyl aromatic polymer, α-olefin polymer and compatibilizer.  
     
     
         16 . The improvement of  claim 10 , wherein the poly(alkenyl aromatic) polymer is polystyrene, the ethylene polymer is polyethylene or a copolymer of ethylene and up to about 10 mole-% of another α-olefin and said compatibilizer olefin and said compatibilizer includes a substantially random interpolymer having a melt flow index (190° C./2.16 kg) of 0.1 to 50 g/10 min, an M w /M n  of 1.5 to 20; which contains, in polymerized form; 
 (1) from 3 to 55 mol percent of polymer units derived from; 
 (a) at least one vinyl or vinylidene aromatic monomer, or  
 (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or  
 (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and  
 
 (2) from 45 to 97 mol percent of repeating units derived from ethylene and/or a C 3-20  α-olefin; and  
 (3) no more than 20 mol percent of repeating units derived from one or more of ethylenically unsaturated polymerizable monomers other than (1) and (2).  
 
     
     
         17 . The improvement of  claim 10 , wherein said compatibilizer is a hydrogenated block copolymer of monovinylidene aromatic monomer and a conjugated diene, the alkenyl aromatic polymer is polystyrene and the α-olefin polymer is polyethylene or a copolymer of ethylene and up to about 15 mole-% of another α-olefin.  
     
     
         18 . The improvement of  claim 10 , wherein said compatibilizer is a block copolymer of styrene and ethylene, the alkenyl aromatic polymer is polystyrene and the α-olefin polymer is polyethylene or a copolymer of ethylene and up to about 15 mole-% of another α-olefin.  
     
     
         19 . A method for acoustical insulation in a building construction comprising installing in a floor, wall or ceiling a foam of a polymer blend including (a) at least one alkenyl aromatic polymer, (b) at least one α-olefin polymer and (c) an effective amount of a compatibilizer for said alkenyl aromatic polymer and said α-olefin polymer at the relative proportions thereof that are present in said polymer blend.  
     
     
         20 . An acoustical foam useful for acoustical insulation in a building construction comprising (a) at least one alkenyl aromatic polymer, (b) at least one α-olefin polymer and (c) an effective amount of a compatibilizer for said alkenyl aromatic polymer and said α-olefin polymer at the relative proportions thereof that are present in said polymer blend, said foam having a density of from about 10-60 kg/m 3 , a dynamic stiffness of from about 9-500 MN/m 3 , a thickness of 3-20 mm, and a width of from about 0.1 to 2 meters.  
     
     
         21 . An acoustical foam useful for acoustical insulation in a building construction comprising (a) about 25 to about 75% by weight polystyrene, (b) about 25 to about 50% by weight polyethylene or a copolymer of ethylene and up to about 15 mole-percent of another α-olefin and (c) about 2 to about 50% by weight of a substantially random interpolymer having a melt flow index (190° C./2.16 kg) of 0.1 to 50 g/10 min, and an M w /M n  of 1.5 to 20; which contains, in polymerized form; 
 (1) from 3 to 55 mol percent of polymer units derived from; 
 (a) at least one vinyl or vinylidene aromatic monomer, or  
 (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or  
 (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and  
 
 (2) from 45 to 97 mol percent of repeating units derived from ethylene and/or a C 3-20  α-olefin; and  
 (4) no more than 20 mol percent of repeating units derived from one or more of ethylenically unsaturated polymerizable monomers other than (1) and (2) the % by weight of each of components (a), (b) and (c) being based on the total weight of components (a), (b) and (c), said foam having a density of from about 10-60 kg/m 3 , a dynamic stiffness of from about 9-500 MN/m 3 , a thickness of 3-20 mm, and a width of from about 0.1 to 2 meters.