Hot melt adhesive composition

Abstract

A hot melt adhesive that is useful in the production of textiles, such as a tuft carpet, contains a blend of constituents that allows synthetic carpet members to be fully recycled without first separating the adhesive from the carpet members. The adhesive includes: a) from about 5 to about 30 weight % of a copolymer of an alkyl acrylate having from 2 to 18 carbon atoms; b) from about 5 to about 50 weight % of a wax and desirably a C10 wax; c) up to about 75 weight % of a filler; and d) from about 0.1 to about 10 weight % of an aliphatic carboxylic acid having from 8 to 24 carbon atoms.

We claim:  
     
         1 . A hot melt adhesive composition, comprising: 
 a) from about 5 to about 30 weight % of at least one copolymer of an alkyl acrylate having from 2 to 18 carbon atoms;    b) from about 5 to about 50 weight % of a wax;    c) up to about 75 weight % of a filler; and    d) from about 0.1 to about 10 weight % of an aliphatic carboxylic acid having from 8 to 32 carbon atoms.    
     
     
         2 . The adhesive of  claim 1  wherein said alkyl acrylate is selected from the group consisting of ethylene (meth)acrylate, methyl (meth)acrylate, propyl acrylate, butyl (meth)acrylate, hexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate and mixtures thereof.  
     
     
         3 . The adhesive of  claim 1  wherein said alkyl acrylate is selected from the group consisting of ethylene (meth)acrylate and ethylene n-butyl (meth)acrylate.  
     
     
         4 . The adhesive of  claim 1  wherein said wax is selected from the group consisting of paraffin waxes, microcrystalline waxes, high density low molecular weight polyethylene waxes, by-product polyethylene waxes, Fischer-Tropsch waxes, oxidized Fischer Tropsch waxes, hydroxy waxes, stearamide waxes and mixtures thereof.  
     
     
         5 . The adhesive of  claim 1  wherein said wax has from 6 to 20 carbon atoms.  
     
     
         6 . The adhesive of  claim 1  wherein said wax has from 6 to 15 carbon atoms.  
     
     
         7 . The adhesive of  claim 1  wherein said wax has from 8 to 10 carbon atoms.  
     
     
         8 . The adhesive of  claim 1  wherein said aliphatic carboxylic acid is from about 1 to about 5 weight % and has from 12 to 18 carbon atoms.  
     
     
         9 . The adhesive of  claim 8  wherein said aliphatic carboxylic acid is stearic acid.  
     
     
         10 . The adhesive of  claim 1  wherein said filler is selected from the group consisting of calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, silica, fly ash, and mixtures thereof.  
     
     
         11 . The adhesive of  claim 1  further comprising at least one constituent selected from the group an antioxidant, a plasticizer, a tackifier, and a flame retardant.  
     
     
         12 . A hot melt adhesive composition, comprising: 
 a) from about 5 to about 30 weight % of at least one copolymer of an alkyl acrylate selected from the group consisting of methyl acrylate, ethylene (meth)acrylate, propyl acrylate, butyl (meth)acrylate, hexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate and mixtures thereof;    b) from about 5 to about 50 weight % of a wax having from 6 to 20 carbon atoms;    c) up to about 75 weight % of a filler; and    d) from about 0.1 to about 10 weight % of an aliphatic carboxylic acid having from 8 to 32 carbon atoms.    
     
     
         13 . The hot melt adhesive composition of  claim 12  wherein said alkyl acrylate is an ethylene (meth)acrylate.  
     
     
         14 . The hot melt adhesive composition of  claim 12  wherein said wax is selected from the group consisting of paraffin waxes, microcrystalline waxes, high density low molecular weight polyethylene waxes, by-product polyethylene waxes, Fischer-Tropsch waxes, oxidized Fischer Tropsch waxes, hydroxy waxes, stearamide waxes and mixtures thereof.  
     
     
         15 . The hot melt adhesive composition of  claim 12  wherein said filler is selected from the group consisting of calcium carbonate, clay, magnesium carbonate, calcium sulfate, alumina, talc, barium sulfate, silica, carbon black, aluminum hydroxide, magnesium hydroxide and mixtures thereof.  
     
     
         16 . The hot melt adhesive composition of  claim 12  wherein said filler is from about 15 to about 70 weight % of the composition.  
     
     
         17 . The hot melt adhesive composition of  claim 12  wherein said filler is from about 25 to 65 weight % of the composition.  
     
     
         18 . The hot melt adhesive composition of  claim 12  wherein said carboxylic acid has from 12 to 18 carbon atoms.  
     
     
         19 . The hot melt adhesive composition of  claim 12  further comprising at least one of an antioxidant, a plasticizer, a tackifier, a flame retardant, and a colorant.  
     
     
         20 . The hot melt adhesive composition of  claim 19  wherein said antioxidant is selected from the group consisting of 1,3,5-trimethyl 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl)benzene; pentaerythrityl tetrakis-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate; 4,4′-methylenebis(2,6-tert-butylphenol); 4,4′-thiobis(6-tert-butyl-o-cresol); 2,6-di-tertbutylphenol; 6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-1,3,5 triazine; di-n-octylthio)ethyl 3,5-di-tert-butyl-4-hydroxy-benzoate; and sorbitol hexa(3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate).  
     
     
         21 . The hot melt adhesive composition of  claim 19  wherein said plasticizer is selected from the group consisting of 2-ethylhexanol, cyclohexanol, phenol, naphthol, 1,2-benzene dicarboxylic acid, 1,3-benzene dicarboxylic acid (isophthalic acid), 1,4-benzene dicarboxylic acid (terephthalic acid), dioctyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, diphenyl phthalate, ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, glycerine, glucose, fructose, sucrose, mannitol, trimethylolethane, 1,4-cyclohexanedimethanol, pentaerythritol, 2,2-dimethyl-1,3-propanediol, 2-hydroxymethyl-2-methyl-1,3-propanediol, neopentyl glycol, ethylene glycol dibenzoate, propylene glycol dibenzoate, trimethylene glycol tribenzoate, trimethylol ethane tribenzoate, glycerol tribenzoate, sucrose benzoate, pentaerythritol tetrabenzoate, 2,2-dimethyl-1,3-propanediol dibenzoate, trimethylene glycol dibenzoate, glycerol tribenzoate, 2-hydroxymethyl-2-methyl-1,3-propanedioltribenzoatepentaerythritoltetraben zoate, neopentyl glycol dibenzoate and mixtures of these plasticizers.  
     
     
         22 . A multi-layer laminated article comprising: 
 a. a first layer selected from the group consisting of polypropylene and polyamides; and    b. a second layer comprising a hot melt adhesive composition, comprising: 
 i) from about 5 to about 30 weight % of at least one copolymer of an alkyl acrylate selected from the group consisting of methyl acrylate, ethylene (meth)acrylate, propyl acrylate, butyl (meth)acrylate, hexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate and mixtures thereof;  
 ii) from about 5 to about 50 weight % of a wax having from 6 to 20 carbon atoms;  
 iii) up to about 75 weight % of a filler; and  
 iv) from about 0.1 to about 10 weight % of an aliphatic carboxylic acid having from 8 to 32 carbon atoms.  
   
     
     
         23 . The multi-layer laminated article of  claim 22  wherein said wax is selected from the group consisting of paraffin waxes, microcrystalline waxes, high density low molecular weight polyethylene waxes, by-product polyethylene waxes, Fischer-Tropsch waxes, oxidized Fischer Tropsch waxes, hydroxy waxes, stearamide waxes and mixtures thereof.  
     
     
         24 . The multi-layer laminated article of  claim 23  wherein said filler is from about 25 to 65 weight % of the composition and is selected from the group consisting of calcium carbonate, clay, magnesium carbonate, calcium sulfate, alumina, talc, barium sulfate, silica, carbon black, aluminum hydroxide, magnesium hydroxide and mixtures thereof.  
     
     
         25 . The multi-layer laminated article of  claim 22  wherein said carboxylic acid has from 12 to 18 carbon atoms.  
     
     
         26 . A recyclable carpet composition comprising: 
 a. a first layer selected from the group consisting of polypropylene and polyamides; and    b. a second layer comprising a hot melt adhesive composition, comprising: 
 i) from about 5 to about 30 weight % of at least one copolymer of an alkyl acrylate selected from the group consisting of methyl acrylate, ethylene (meth)acrylate, propyl acrylate, butyl (meth)acrylate, hexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl acrylate and mixtures thereof;  
 ii) from about 5 to about 50 weight % of a wax having from 6 to 20 carbon atoms;  
 iii) up to about 75 weight % of a filler; and  
 iv) from about 0.1 to about 10 weight % of an aliphatic carboxylic acid having from 8 to 32 carbon atoms.  
   
     
     
         27 . The recyclable carpet composition of  claim 26  wherein said wax is selected from the group consisting of high density low molecular weight polyethylene waxes, and by-product polyethylene waxes having from 6 to 15 carbon atoms, from about 25 to 65 weight % filler, and said aliphatic carboxylic acid is from about 1 to about 5 weight % stearic acid.