| abstract |
An improvement in a process wherein an organotin compound is used as ancatalyst is disclosed, wherein the improvement comprises:n A) employing a latent catalyst that is substantially catalytically ineffectivenat room temperature, wherein said latent catalyst is selected from the groupnconsisting of unsymmetrically substituted tetrahydrocarbyl tin compounds ofnthe formula:n R x R' 4-x Sn nwherein nR is a hydrocarbyl group that is substantially inert under usual conditions ofnstorage and use, nR' is a hydrocarbyl group that is more reactive than R under conditions of use, nx is 1, 2, or 3; and B) then heating the curable mixture to a temperature in the range of fromnabout 30 up to about 99° C to activate the catalyst. |