Thermally expandable material useful for reducing vibratioin transfer

Abstract

A thermally expandable material is provided that, once expanded, has a Young's storage modulus E′ between 0.1 MPa and 1000 MPa, a loss factor of at least 0.3 (preferably, at least 1) and preferably a shear storage modulus G′ between 0.1 MPa and 500 MPa at a temperature between −10 and +40 degrees C. in the frequency range 0 to 500 Hz. Such materials are useful in combination with a carrier to form a dissipative vibratory wave barrier that effectively reduces the transfer of vibrations from a vibration generator, as may be present in a vehicle.

1 . A thermally expandable material that when expanded has a Young's storage modulus E′ between 0.1 MPa and 1000 MPa and a loss factor higher than 0.3 at a temperature between −10 and +40 degrees C. in the frequency range 0 to 500 Hz. 
     
     
         2 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises at least one thermoplastic elastomer, at least one non-elastomeric thermoplastic, at least one stabilizer or antioxidant, at least one blowing agent, and at least one curing agent. 
     
     
         3 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one peroxide curing agent. 
     
     
         4 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one thermoplastic elastomer selected from the group consisting of thermoplastic polyurethanes, styrene/butadiene block copolymers, hydrogenated styrene/butadiene block copolymers, styrene/isoprene block copolymers, and hydrogenated styrene/isoprene block copolymers. 
     
     
         5 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one non-elastomeric thermoplastic selected from the group consisting of ethylene/vinyl acetate copolymers and ethylene/methyl acrylate copolymers. 
     
     
         6 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one olefinically unsaturated monomer or oligomer. 
     
     
         7 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one plasticizer. 
     
     
         8 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one wax. 
     
     
         9 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one latent chemical blowing agent. 
     
     
         10 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one tackifying resin. 
     
     
         11 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one blowing agent activator. 
     
     
         12 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material is comprised of at least one styrene/isoprene/styrene triblock polymer or fully or partially hydrogenated derivative thereof with at least about 50% of the polymerized isoprene monomer moieties having 1,2 and/or 3,4 configurations. 
     
     
         13 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises:
 a). from 25 to 70% by weight of at least one thermoplastic elastomer;   b). from 15 to 40% by weight of at least one non-elastomeric thermoplastic;   c). from 0.01 to 2% by weight of at least one stabilizer or antioxidant;   d). from 2 to 15% by weight of at least one blowing agent; and   e). from 0.5 to 4% by weight of at least one curing agent.   
     
     
         14 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises:
 a). from 35 to 55% by weight of at least one thermoplastic elastomer selected from the group consisting of thermoplastic polyurethanes, styrene/butadiene block copolymers, hydrogenated styrene/butadiene block copolymers, styrene/isoprene block copolymers, and hydrogenated styrene/isoprene block copolymers;   b). from 20 to 35% by weight of at least one non-elastomeric thermoplastic selected from the group consisting of ethylene/vinyl acetate copolymers and ethylene/methyl acrylate copolymers;   c). from 0.05 to 1% by weight of at least one stabilizer or antioxidant;   d). at least one latent chemical blowing agent in an amount effective to cause the expandable material to expand at least 100% in volume when heated at a temperature of 150 degrees C. for at least 20 minutes;   e). from 0.5 to 4% by weight of at least one peroxide; and   f). from 0.5 to 2% by weight of at least one olefinically unsaturated monomer or oligomer; wherein said thermally expandable material contains less than 10% by weight filler.   
     
     
         15 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises:
 a). from 25 to 70% by weight of at least one thermoplastic elastomer;   b). from 15 to 40% by weight of at least one non-elastomeric thermoplastic;   c). from 0.01 to 2% by weight of at least one stabilizer or antioxidant;   d). from 2 to 15% by weight of at least one blowing agent;   e). from 0.5 to 4% by weight of at least one curing agent;   f). at least one tackifying resin, in an amount up to 10% by weight;   g). at least one wax, in an amount up to 10% by weight; and   h). at least one plasticizer, in an amount up to 5% by weight.   
     
     
         16 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises:
 a). from 35 to 55% by weight of at least one styrene/isoprene block copolymer thermoplastic elastomer selected from the group consisting of styrene/isoprene block copolymers;   b). from 20 to 35% by weight of at least one non-elastomeric thermoplastic selected from the group consisting of ethylene/vinyl acetate copolymers;   c). from 0.05 to 1% by weight of at least one stabilizer or antioxidant;   d). at least one latent chemical blowing agent in an amount effective to cause the expandable material to expand at least 100% in volume when heated at a temperature of 150 degrees C. for at least 20 minutes;   e). from 0.5 to 4% by weight of at least one organic peroxide;   f). from 0.5 to 2% by weight of at least one C 1  to C 6  alkyl (meth)acrylate;   g). at least one tackifying resin, in an amount up to 10% by weight;   h). at least one plasticizer, in an amount up to 5% by weight; and   i). at least one wax, in an amount up to 10% by weight; wherein said thermally expandable material contains less than 10% by weight filler.   
     
     
         17 . A thermally expandable material in accordance with  claim 16 , wherein at least about 50% of the polymerized isoprene monomer moieties in said at least one styrene/isoprene block copolymer thermoplastic elastomer have 1,2 and/or 3,4 configurations. 
     
     
         18 . A thermally expandable material in accordance with  claim 1 , wherein said thermally expandable material comprises:
 a). from 35 to 55% by weight of at least one styrene/isoprene block copolymer thermoplastic elastomer selected from the group consisting of styrene/isoprene block copolymers;   b). from 20 to 35% by weight of at least one non-elastomeric thermoplastic selected from the group consisting of ethylene/vinyl acetate copolymers;   c). from 0.05 to 1% by weight of at least one stabilizer or antioxidant;   d). at least one latent chemical blowing agent in an amount effective to cause the expandable material to expand at least 100% in volume when heated at a temperature of 150 degrees C. for at least 20 minutes;   e). from 0.5 to 4% by weight of at least one curing agent capable of inducing free radical reactions;   g). at least one tackifying resin, in an amount up to 10% by weight; and   h). at least one plasticizer, in an amount up to 5% by weight.   
     
     
         19 . A thermally expandable material in accordance with  claim 18 , wherein at least about 50% of the polymerized isoprene monomer moieties in said at least one styrene/isoprene block copolymer thermoplastic elastomer have 1,2 and/or 3,4 configurations.