Silicon-containing polyols

Claim 1

An organic coating composition comprising: I. a silicon-containing polyol comprising a reaction product prepared by reacting: (A) at least one hydrophobic polyol; (B) an organosilicon-containing material comprising (1) at least one organosilicon-containing substance free of functional groups attached directly to carbon and essentially free of alkali metal ions, having atoms bonded directly to Si, all of said atoms being selected from the group consisting of O, N, Cl and combinations thereof, said organosilicon-containing substance additionally having moieties directly bonded to Si which are displaceable by reaction with water and/or alcohol, wherein, optionally, at least a part of said organosilicon-containing substance is hydrolyzed to a compound or a mixture of compounds, said compound or mixture of compounds containing a residual amount of said moieties directly bonded to Si which are displaceable; (2) optionally a nonfunctional organosilane, a hydrolyzed nonfunctional organosilane, or a mixture thereof; and (3) optionally a functional organosilane, a hydrolyzed functional organosilane or a mixture thereof; and (C) at least one higher monofunctional alcohol corresponding to the formula R-OH wherein R represents alkyl of at least 4 carbon atoms, aryl, alkylaryl, arylalkyl, alkyloxyalkyl, or aryloxyalkyl; wherein said reaction product has a content of hydroxyl groups from said polyol ranging from 0.4 to 10 milliequivalents per gram of said reaction product, has a content of groups RO-- from said higher monofunctional alcohol ranging from 0.1 to 7 milliequivalents per gram of said reaction product, has a content of said moieties directly bonded to Si which are displaceable of less than 1 milliequivalent per gram of said reaction product and remains ungelled when subjected to a two-step gel test consisting of (1) heating a 10 gram sample of said reaction product at 177° C. for 240 minutes in a glass jar covered by a piece of masking tape, followed by repeating step 1 in the presence of 0.5 grams of stannous octoate; and II. a curing agent for said silicon-containing polyol; wherein said coating composition is essentially free of elemental zinc and cures to an essentially organic coating.