Low odor, light color, disposable article construction adhesive

Abstract

We have found a novel spray-on adhesive composition made from components including a high melt index copolymer and a high melt tackifier that interact to produce a composition that can form a low odor, light color, non-tacky, hot melt adhesive material that can be used in disposable article manufacture. The adhesive is thermally stable at hot melt application conditions, is low in cost, is easily applied and produces high quality disposable articles.

1 . A disposable article comprising a film layer bonded to a non-woven layer using a hot melt construction adhesive, the construction adhesive comprising: 
 (a) greater than about 40 wt % of a copolymer comprising ethylene and a methacrylate monomer or mixtures thereof having a melt index greater than 1000 gm-10 min−1; and    (b) an effective amount of a hydrogenated hydrocarbon tackifying resin with a softening point greater than 120° C.;    wherein the weight ratio of the polymer to the tackifying resin is greater than about 1: 1.    
   
   
       2 . The article of  claim 1  wherein the adhesive has a softening point of less than about 95° C.  
   
   
       3 . The article of  claim 1  wherein the weight ratio is greater than 1.5:1 and the adhesive has a softening point less than the 85° C.  
   
   
       4 . The article of  claim 1  wherein the weight ratio is greater than 1.8:1.  
   
   
       5 . The article of  claim 1  wherein the methacrylate monomer is methylmethacrylate and the polymer is an ethylene/methylmethacrylate copolymer.  
   
   
       6 . The article of  claim 5  wherein the ethylene/methylmethacrylate copolymer is present in an amount of about 60 to 85 wt %.  
   
   
       7 . The article of  claim 7  wherein the ethylene/methylmethacrylate copolymer has a melt index greater than 2700 gm-10 min −1 .  
   
   
       8 . The article of  claim 7  wherein the tackifying resin is present in the adhesive in an amount of 20 to 40 wt %.  
   
   
       9 . The article of  claim 1  wherein the adhesive has a viscosity of 4000 to 8000 cP at 150° C.  
   
   
       10 . The article of  claim 1  wherein the film comprises a polymer selected from a polyvinyl chloride, a polyolefin or mixtures thereof and the non-woven comprises a synthetic fiber.  
   
   
       11 . The article of  claim 5  wherein the ethylene/methylmethacrylate copolymer comprises a blend of a first copolymer having a melt index different than a second copolymer.  
   
   
       12 . The article of  claim 5  wherein the ethylene/methylmethacrylate copolymer is present in the adhesive at a weight ratio copolymer to tackifying resin of at least 2:1.  
   
   
       13 . The article of  claim 5  wherein the ethylene/methylmethacrylate copolymer is present in an amount of about 60 to 85 wt %.  
   
   
       14 . The article of  claim 6  wherein the ethylene/methylmethacrylate copolymer has a melt index greater than 950 gm-10 min −1 .  
   
   
       15 . The article of  claim 6  wherein the tackifying resin is present in the adhesive in an amount of 20 to 40 wt %.  
   
   
       16 . The article of  claim 1  wherein the tackifying resin comprises a blend of a first tackifier and a second tackifier wherein the first has a melting point 5 ° C. different than the second.  
   
   
       17 . The article of  claim 1  wherein the adhesive consists essentially of 62 to 75 wt % of a copolymer comprising ethylene and a methacrylate monomer, the copolymer having a melt index of about 850 to 1250 gm-10 min −1  and about 25 to 50 wt % of a hydrogenated hydrocarbon tackifying resin with a softening point greater than about 100° C.; wherein the weight ratio of the copolymer to the resin is greater than about 1:1 and the adhesive has a softening point of less than about 95° C.  
   
   
       18 . The article of  claim 1  wherein the adhesive consists essentially of 62 to 75 wt % of a copolymer comprising ethylene and a methacrylate monomer, the copolymer having a melt index of about 2500 to 3000 gm-10 min −1  and about 25 to 50 wt % of a hydrogenated hydrocarbon tackifying resin with a softening point greater than about 100° C.; wherein the weight ratio of the copolymer to the tackifying resin is greater than about 1:1 and the adhesive has a softening point of less than about 95° C.