Accelerate cure of moisture curable polyurethane adhesive compositions useful for bonding glass

Abstract

The adhesive system of the invention is especially useful in bonding replacement windows into vehicles. They allow for sufficient working time while still realizing a fast drive away time. The adhesive system is comprised of a moisture curable adhesive and a cure accelerator that may be applied using a simple single caulk gun and may be applied at ambient temperatures such as −10° C. and about 45° C. The cure accelerator is comprised of a polyol having a backbone that has at least one amine in the backbone. The moisture curable adhesive typically is comprised of an isocyanate terminated prepolymer.

1 . An adhesive system comprised of a moisture curable adhesive comprised of an isocyanate terminated prepolymer and a separate cure accelerator comprised of a polyol having a backbone comprised of at least one amino group. 
     
     
         2 . The adhesive system of  claim 1  wherein the moisture curable adhesive and cure accelerator are provided in a volumetric ratio of moisture curable adhesive/cure accelerator of 5 to 200. 
     
     
         3 . The adhesive system of  claim 2  wherein said volumetric ratio is at most 20. 
     
     
         4 . The adhesive system of  claim 1 , wherein the prepolymer is comprised of an isocyanated terminated polyether prepolymer. 
     
     
         5 . The adhesive system of  claim 4 , wherein the isocyanated terminated polyether prepolymer is comprised of a polyether backbone comprised of an ethylene oxide, a propylene oxide, or combination of these. 
     
     
         6 . The adhesive system of  claim 1 , wherein the polyol having an amino group has an average OH functionality of at least 2 to 4.5. 
     
     
         7 . The adhesive system of  claim 6 , wherein the polyol has an average OH functionality of at least 3.5 to 4.2. 
     
     
         8 . The adhesive system of  claim 1 , wherein the polyol having an amino group has an apparent pH of at least 10. 
     
     
         9 . The adhesive system of  claim 9 , wherein the apparent pH is at least 11. 
     
     
         10 . The adhesive system of  claim 1 , wherein the polyol having an amino group has an OH# of at least 100. 
     
     
         11 . The adhesive system of  claim 1 , wherein said polyol has an OH# of at least 550. 
     
     
         12 . The adhesive system of  claim 1 , wherein the moisture curable adhesive is further comprised of at least one of the following a filler, plasticizer, polyisocyanate monomer or oligomer, and catalyst. 
     
     
         13 . The adhesive system of  claim 12 , wherein the moisture curable adhesive is comprised of the plasticizer and the plasticizer is linear, branched or combination thereof. 
     
     
         14 . The adhesive system of  claim 1 , wherein the cure accelerator further comprises at least one of the following a polyol not having an amino group, a catalyst and a filler. 
     
     
         15 . A method of accelerating the cure of an adhesive composition comprising:
 a) providing a moisture curable adhesive composition comprised of an isocyanate terminated prepolymer and a cure accelerator comprised of a polyol having a backbone comprised of at least one amino group, wherein the moisture curable adhesive and cure accelerator are separately provided;   b) mixing the cure accelerator and the adhesive composition to form an adhesive mixture;   c) applying the adhesive mixture to at least a portion of a first substrate;   d) contacting the substrate having the adhesive mixture thereon with a second substrate such that the adhesive mixture is therebetween; and   e) allowing the adhesive mixture to cure bonding said substrates together.   
     
     
         16 . The method of  claim 15 , wherein the providing of the moisture curable adhesive and cure accelerator are provided in an amount volumetrically in a ratio of moisture curable adhesive/cure accelerator of 5 to 200. 
     
     
         17 . The method of  claim 16  wherein the ratio is 5 to 20. 
     
     
         18 . The method of  claim 16 , wherein the first substrate is a substrate wherein at least a portion of the substrate is optically transparent and the second substrate is a vehicle or building. 
     
     
         19 . The method of  claim 18 , wherein the first substrate has an opaque portion where the adhesive mixture is applied and contacted with the second substrate. 
     
     
         20 . The method of  claim 19 , wherein the first substrate is glass or polycarbonate.