Shelf-stable silane-modified aqueous dispersion polymers

Abstract

Disclosed herein is a process for preparing a shelf-stable, one-pack, silane modified (meth)acrylic latex interpolymer composition, wherein the process comprises continuously adding at least a portion of a mixture comprising at least 0.5 mole percent of a vinyl silane comprising hydrolyzable groups and up to 99.5 mole percent of a (meth)acrylic monomer to water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 throughout the reaction, while simultaneously hydrolyzing from about 10 to about 60% of the hydrolyzable groups of the vinyl silane.

What is claimed is:  
     
         1 . A process for preparing a shelf-stable, one-pack, silane modified (meth)acrylic latex interpolymer composition comprising continuously adding at least a portion of a mixture comprising at least 0.5 mole percent of a vinyl silane comprising hydrolyzable groups and up to 99.5 mole percent of a (meth)acrylic monomer to water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 throughout the reaction, while simultaneously hydrolyzing from about 10 to about 60% of the hydrolyzable groups of the vinyl silane.  
     
     
         2 . The process of  claim 1  wherein the vinyl silane comprising hydrolyzable groups is a vinylalkoxysilane.  
     
     
         3 . The process of  claim 2  wherein the vinylalkoxysilane is selected from the group consisting of vinyltriethoxysilane and vinylmethyldiethoxysilane.  
     
     
         4 . The process of  claim 3  wherein the vinylalkoxysilane is vinyltriethoxysilane.  
     
     
         5 . The process of  claim 1  wherein the (meth)acrylic monomer is selected from the group consisting of methyl methacrylate, butyl acrylate, methacrylic acid, and mixtures thereof.  
     
     
         6 . The process of  claim 1  wherein the buffer is sodium bicarbonate.  
     
     
         7 . The process of  claim 6  wherein the buffer is employed at a level of from about 0.4% to about 0.7% of the aqueous phase.  
     
     
         8 . The process of  claim 1  wherein the mixture further comprises up to about 20 weight percent of at least one vinyl organic polymer.  
     
     
         9 . The process of  claim 8  wherein at least one vinyl organic polymer is vinyl acetate.  
     
     
         10 . A shelf-stable, one-pack, silane modified (meth)acrylic latex interpolymer composition prepared by a process comprising continuously adding at least a portion of a mixture comprising at least 0.5 mole percent of a vinyl silane comprising hydrolyzable groups and up to 99.5 mole percent of a (meth)acrylic monomer to water and a surfactant in a reaction vessel, wherein said addition is carried out in the presence of a polymerization initiator and buffer sufficient to maintain the pH of the reaction at a level of at least 6 throughout the reaction, while simultaneously hydrolyzing from about 10 to about 60% of the hydrolyzable groups of the vinyl silane.  
     
     
         11 . The composition of  claim 10  wherein the vinyl silane comprising hydrolyzable groups is a vinylalkoxysilane.  
     
     
         12 . The composition of  claim 11  wherein the vinylalkoxysilane is selected from the group consisting of vinyltriethoxysilane and vinylmethyldiethoxysilane.  
     
     
         13 . The composition of  claim 10  wherein the (meth)acrylic monomer is selected from the group consisting of methyl methacrylate, butyl acrylate, methacrylic acid, and mixtures thereof.  
     
     
         14 . The composition of  claim 10  wherein the buffer is sodium bicarbonate.  
     
     
         15 . The composition of  claim 14  wherein the buffer is employed at a level of from about 0.4% to about 0.7% of the aqueous phase.  
     
     
         16 . The composition of  claim 10  wherein the mixture further comprises up to about 20 weight percent of at least one vinyl organic polymer.  
     
     
         17 . The composition of  claim 16  wherein at least one vinyl organic polymer is vinyl acetate.  
     
     
         18 . An interpolymer composition comprising: 
 A) at least about 0.5 mole percent of a vinylalkoxysilane moiety in which from about 10 to about 60% of the alkoxy groups have been hydrolyzed; and, correspondingly,    B) up to about 99.5 mole percent of at least one (meth)acrylic moiety.    
     
     
         19 . The interpolymer of  claim 18  wherein the vinylalkoxysilane is vinyltriethoxysilane.  
     
     
         20 . The interpolymer of  claim 18  wherein the (meth)acrylic moiety is selected from the group consisting of methyl methacrylate, butyl acrylate, methacrylic acid, and mixtures thereof.