Low Viscosity Dimethoxy Amino Silane Polyurethane with Triethoxy Silyl Groups for Sealants and Adhesives with Easy Processing, High Tensile Strength and Low Methanol Emissions on Curing

Abstract

The present method relates to the production of low viscosity dimethoxy amino silane polyurethane with triethoxy silyl groups, as well as the production of sealants, adhesive and paint compositions using the alcoxysilane capped polymers formed from the present method. The method of production results in final alcoxysilane capped polymers that have a low viscosity and are safer for manufacturers, and end users.

What is claimed is: 
     
         1 . A method of producing methyl dimethoxy silane and triethoxy capped polymer, the method comprising:
 creating a polymeric composition by:   supplying a hydroxyl terminated polypropylene glycol polyether;   capping some of the hydroxyl terminated polypropylene glycol polyether with diisocyanate;   capping the remaining NCO groups with a secondary amino silane;   capping the remaining hydroxyl groups of the polypropylene glycol polyether with isocyanato silane; and   modifying the viscosity with the addition of vinyl silane and methanol.   
     
     
         2 . The method recited in  claim 1  wherein the polymeric composition comprises a polyurethane comprising hydroxyl groups. 
     
     
         3 . The method recited in  claim 1  wherein the polymeric composition comprises a polyether. 
     
     
         4 . The method recited in  claim 1  wherein the polymeric composition comprises a polyester comprising hydroxyl groups. 
     
     
         5 . The method recited in  claim 1  where the polymeric composition comprises of acrylic groups and any combination of above polyols comprising reactive hydroxyl groups. 
     
     
         6 . The method of  claim 1  where the diisocyanate is isophorone diisocyanate and is partially reacted with 30 to 70 percent of the available hydroxyl groups at low temperatures. 
     
     
         7 . The method of  claim 1  where the unreacted NCO groups are nearly 100 percent capped at low temperature by a secondary silane. 
     
     
         8 . The method as disclosed in  claim 7  wherein the secondary silane is cyclohexyl amino propyl methyl dimethoxy silane. 
     
     
         9 . The method of  claim 1  wherein the polymer composition remaining hydroxyl groups are reacted with isocyanato propyl triethoxy silane. 
     
     
         10 . The method of  claim 1  wherein the reaction is carried out in such that 80 percent or more of the polypropylene glycol chains have different alkoxy end groups, wherein the alkoxy end groups are moisture reactive. 
     
     
         11 . The method of  claim 1  wherein the alkoxy silane end groups are chosen to ensure the polymer composition has a low moisture sensitivity. 
     
     
         12 . A polymer composition formed by the method as disclosed in  claim 1 . 
     
     
         13 . The polymer composition as claimed in  claim 12 , wherein the isocyanato propyl triethoxy silane is added first. 
     
     
         14 . The polymer composition as claimed in  claim 12 , wherein the secondary amino silane is reacted first with the diisocyanate molecule and then reacted with the polypropylene glycol hydroxyl groups. 
     
     
         15 . An adhesive formed from the polymer composition as claimed in  claim 12 . 
     
     
         16 . A sealant formed from the polymer composition as claimed in  claim 12 . 
     
     
         17 . A paint composition formed from the polymer composition as claimed in  claim 12 .