| 摘要 |
The invention relates to antifreeze concentrates for cooling systems in fuel cell drives, from which are produced ready-to-use aqueous cooling agent compositions having a maximum conductivity of 50 mus/cm, based on alkylene glycols or the derivatives thereof, and containing orthosilicic acid esters of formula (I) wherein the variables R<SUP>1 </SUP>to R<SUP>4 </SUP>are the same or different and represent C<SUB>1</SUB>-C<SUB>20 </SUB>alkyl substituents, C<SUB>2</SUB>-C<SUB>20 </SUB>alkenyl substituents, C<SUB>1</SUB>-C<SUB>20 </SUB>hydroxyalkyl substituents, optionally substituted C<SUB>6</SUB>-C<SUB>12 </SUB>aryl substituents and/or glycol ether substituents of formula (CH<SUB>2</SUB>-CH<SUB>2</SUB>-O)<SUB>n</SUB>-R<SUP>5 </SUP>wherein R<SUP>5 </SUP>represents hydrogen or C<SUB>1</SUB>-C<SUB>5 </SUB>alkyl and n represents a number between 1 and 5 |
