| 摘要 |
A composition which retains a flash point of more than 21° C. even on storage and is obtainable by mixing and reacting(i) from 50 to 70% by weight of at least one alkyltrialkoxysilane,(ii) from 10 to 25% by weight of at least one alkoxysiloxane and/or at least one tetraalkoxysilane,(iii) from 15 to 25% by weight of at least one aqueous silica sol,(iv) from 0.1 to 5% by weight of at least one acid, and(v) from 0.1 to 60% by weight of at least one alcohol and/or glycol, the sum of the above components being not more than 100% by weight,by introducing components (i) and (ii) and also, if desired, a fraction of component (v) as an initial charge, adding component (iii), adjusting the mixture to a temperature in the range from -5 to 10° C., and subsequently adding component (iv), then allowing the mixture to continue reacting, thereafter distilling off hydrolysis alcohol under reduced pressure, and replacing it by adding component (v); which composition is useful for producing a coating on surfaces and also as a base material for paints; a process for preparing such a composition; and coatings and articles obtainable by applying such a composition.
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