Carpet, carpet backings and methods

Abstract

The present invention pertains to carpet and method of making it. In one aspect, the carpet includes (a) a primary backing which has a face and a back surface, (b) a plurality of fibers attached to the primary backing and extending from the face of the primary backing and exposed at the back surface of the primary backing, (c) an adhesive backing, (d) an optional secondary backing adjacent to the adhesive backing, and (e) at least one homogeneously branched linear ethylene polymer. The method includes extrusion coating at least one homogeneously branched linear ethylene polymer onto the back surface of a primary backing to provide an adhesive backing. The method can include additional steps or procedures, either separately or in various combinations. Additional steps and procedures include preheating the primary backing prior the extrusion step, multilayer adhesive backings, washing or scouring the primary backing prior the extrusion step, and utilizing adhesive polymeric additives, high heat content fillers, blowing agents and/or implosion agents. The constructions and methods described herein are particularly suited for making carpet tile.

What is claimed is:  
     
         1 . A method of making a carpet, the carpet comprising yarn attached to a primary backing material having a face and a back side and an adhesive backing material comprised of at least one first and at least one second ethylene polymer layers, wherein the first ethylene polymer layer is in intimate contact with the back surface of the primary backing material, has substantially penetrated and substantially consolidated the yarn, and has a higher melt index than the second ethylene polymer layer, the method comprising the steps of applying the first ethylene polymer layer directly onto the back side of the primary backing material and simultaneously or sequentially applying the second ethylene polymer layer onto the first ethylene polymer layer, wherein one of the first or second ethylene polymer layers comprise an adhesive polymer.  
     
     
         2 . The method of  claim 1  wherein the adhesive polymer is a maleic anhydride grafted ethylene copolymer.  
     
     
         3 . The method of  claim 2  wherein at least one of the first or second ethylene polymer layers comprise at least one homogeneously branched ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) at −30 and 140° C. and a short chain branching distribution index (SCBDI) of greater than about 50 percent.  
     
     
         4 . A carpet tile comprising: 
 a primary backing with a face side and a back side, said primary backing being made from a polyolefin;    polyolefin yarn tufted into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn on the back side of the primary backing;    an adhesive layer of a polyolefin at least partially penetrating the primary backing, the loops of yarn on the back side of the primary backing or both, wherein the adhesive layer comprises at least one homogeneously branched ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) at −30 and 140° C. and a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent.    
     
     
         5 . A carpet tile comprising: 
 a primary backing with a face side and a back side, said primary backing being made from a polyolefin;    polyolefin yarn tufted into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn on the back side of the primary backing;    an adhesive layer of a polyolefin at least partially penetrating the primary backing, the loops of yarn on the back side of the primary backing or both, wherein the adhesive layer comprises a maleic anhydride grafted ethylene copolymer.    
     
     
         6 . A carpet tile comprising: 
 a primary backing with a face side and a back side;    yarn tufted into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yam on the back side of the primary backing;    a first polymeric layer extruded onto the back side of the primary backing and the loops of yarn on the back side of the primary backing, said first polymeric layer comprising at least one homogeneously branched ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) at −30 and 140° C. and a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent;    a reinforcing fabric adjacent the first polymeric adhesive layer; and    a second polymeric layer extruded onto the reinforcing fabric wherein the first polymeric layer.    
     
     
         7 . A carpet tile comprising: 
 a primary backing with a face side and a back side;    yam tufted into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn on the back side of the primary backing;    a first polymeric layer extruded onto the back side of the primary backing and the loops of yarn on the back side of the primary backing, said first polymeric layer comprising a maleic anhydride grafted ethylene copolymer;    a reinforcing fabric adjacent the first polymeric adhesive layer; and    a second polymeric layer extruded onto the reinforcing fabric.    
     
     
         8 . A carpet comprising: 
 a primary backing with a face side and a back side;    yarn tufted into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn on the back side of the primary backing;    a layer of a polyolefin extruded onto the back side of the primary backing and the loops of yam on the back side of the primary backing, wherein the layer comprises maleic anhydride grafted ethylene copolymer.    
     
     
         9 . A method of making a carpet tile comprising the steps 
 providing a primary backing with a face side and a back side, said primary backing being made from a polyolefin;    tufting a polyolefin yarn into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn oh the back side of the primary backing;    extruding an adhesive layer of a polyolefin onto the back side of the primary backing so as to at least partially penetrate the primary backing, the loops of yarn on the back side of the primary backing or both to make a carpet, wherein the adhesive layer comprises at least one homogeneously branched ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) at −30 and 140° C. and a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent; and    cutting the carpet into tiles.    
     
     
         10 . A method of making a carpet tile comprising the steps 
 providing a primary backing with a face side and a back side, said primary backing being made from a polyolefin;    tufting a polyolefin yarn into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yarn on the back side of the primary backing;    extruding an adhesive layer of a polyolefin onto the back side of the primary backing so as to at least partially penetrate the primary backing, the loops of yarn on the back side of the primary backing or both to make a carpet, wherein the adhesive layer comprises a maleic anhydride grafted ethylene polymer; and    cutting the carpet into tiles.    
     
     
         11 . A method of making carpet tile comprising: 
 providing a primary backing with a face side and a back side;    tufting yarn into the primary backing so as to produce a carpet pile on the face side of the primary backing and loops of yam on the back side of the primary backing;    extruding a first polymeric layer onto the back side of the primary backing and the loops of yarn on the back side of the primary backing, wherein the first polymeric layer comprises at least one homogeneously branched ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) at −30 and 140° C. and a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent;    placing a reinforcing fabric adjacent the first polymeric adhesive layer, and    extruding a second polymeric layer onto the reinforcing fabric.    
     
     
         12 . A carpet comprising a primary backing material having a face and a back side, a plurality of fibers attached to the primary backing material and extending from the face of the primary backing material and exposed at the back side of the primary backing material, an adhesive backing material and an optional secondary backing material adjacent to the adhesive backing material, wherein at least one of the plurality of fibers, the primary backing material, the adhesive backing material or the optional secondary backing material is comprised of at least one homogeneously branched linear ethylene polymer characterized as having a single melt point as measured by differential scanning calorimetry (DSC) between −30 and 140° C., a density in the range about 0.86 g/cc to about 0.90 g/cc and a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent.  
     
     
         13 . The carpet of  claim 12  wherein the adhesive backing material is comprised of the at least one homogeneously branched linear ethylene polymer.  
     
     
         14 . The carpet of  claim 12  wherein the homogeneously branched linear ethylene polymer is an interpolymer of ethylene with at least one C 3 -C 20    a -olefin.  
     
     
         15 . The carpet of  claim 14  wherein the homogeneously branched linear ethylene polymer is a copolymer of ethylene and one C 3 -C 20    a -olefin.  
     
     
         16 . The carpet of  claim 15  wherein the one C 3 -C 20    a -olefin is selected from the group consisting of propylene, 1-butene, 1-isobutylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene.  
     
     
         17 . A carpet comprising a primary backing material having a face and a back side, a plurality of fibers attached to the primary backing material and extending from the face of the primary backing material and exposed at the back side of the primary backing material, an adhesive backing material and an optional secondary backing material adjacent to the adhesive backing material, wherein at least one of the plurality of fibers, the primary backing material, the adhesive backing material or the optional secondary backing material is comprised of at least one substantially linear ethylene polymers characterized as having 
 (a) a melt flow ratio, I 10 /I 2  □5.63,    (b) a molecular weight distribution, M w /M n , as determined by gel permeation chromatography and defined by the equation:    ( M   w   /M   n )≦( I   10   /I   2 )−4.63,    (c) a gas extrusion rheology such that the critical shear rate at onset of surface melt fracture for the substantially linear ethylene polymer is at least 50 percent greater than the critical shear rate at the onset of surface melt fracture for a linear ethylene polymer, wherein the linear ethylene polymer has a homogeneously branched short chain branching distribution and no long chain branching, and wherein the substantially linear ethylene polymer and the linear ethylene polymer are simultaneously ethylene homopolymers or interpolymers of ethylene and at least one C 3 -C 20    a -olefin and have essentially the same I 2  and M w /M n  and wherein the respective critical shear rates of the substantially linear ethylene polymer and the linear ethylene polymer are measured at the same melt temperature using a gas extrusion rheometer,    (d) a single differential scanning calorimetry, DSC, melting peak between −30 and 140° C., and    (e) a short chain branching distribution index (SCBDI) of greater than or equal to 50 percent.    
     
     
         18 . The carpet of  claim 17  wherein the adhesive backing material is comprised of the at least one substantially linear ethylene polymer.  
     
     
         19 . The carpet of  claim 17  wherein the substantially linear ethylene polymer is an interpolymer of ethylene with at least one C 3 -C 20    a -olefin.  
     
     
         20 . The carpet of  claim 19  wherein the substantially linear ethylene polymer is a copolymer of ethylene and one C 3 -C 20    a -olefin.  
     
     
         21 . The carpet of  claim 20  wherein the one C 3 -C 20    a -olefin is selected from the group consisting of propylene, 1-butene, 1-isobutylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene.