Patent ID: 9663539
Date: 2017-05-30
CPC Classifications: C07F,C08G

Claim:
1. A process for producing isocyanatoorganosilane having low color and color stability comprising: (a) reacting aminoorganosilane with organic carbonate ester in the presence of basic catalyst to form a reaction mixture containing silylorganocarbamate; (b) neutralizing the reaction mixture of step (a) with an organic carboxylic acid to a pH value equal to or greater than 6.0; (c) stripping the neutralized reaction mixture resulting from step (b) at a temperature of from about 80° C. to about 130° C. so as to provide less than about 5.0 weight percent organic carbonate ester based on the total weight of the stripped reaction mixture; (d) filtering the stripped reaction mixture resulting from step (c); (e) optionally adding an organic carboxylic acid to adjust the pH of the filtered reaction mixture resulting from step (d) to a value equal to or greater than about 6.0; (f) thermally cracking the stripped reaction mixture containing silylorganocarbamate resulting from step (d) or step (e) to provide for an isocyanatoorganosilane and thermally cracked reaction byproducts; (g) separating isocyanatoorganosilane from the thermally cracked reaction byproducts produced in step (f); and (h) collecting the isocyanatoorganosilane from step (g) to provide for isocyanatoorganosilane having low color and color stability.