Silicate-free cooling liquids based on organic acids and carbamates having improved corrosion properties

1 . A coolant or antifreeze concentrate comprising:

a) from 0.05 to 5% by weight of one or more carbamates of the formula

in which

X is O or S,

R is C 1 - to C 8 -alkyl or C 6 - to C 18 -aryl, or the ammonium salts thereof,

b) from 0.05 to 4% by weight of a tricarboxylic acid or of a triazinetriiminocarboxylic acid, or a mixture thereof,

c) from 0.05 to 8% by weight of a mono- or a dicarboxylic acid having 4 to 16 carbon atoms, or a mixture thereof, in the form of their alkali metal or ammonium salts,

d) from 0.01 to 2% by weight of a hydrocarbon-triazole or hydrocarbon-thiazole, or a mixture thereof,

e) from 0.01 to 2% by weight of a water-soluble alkali metal salt or alkaline earth metal salt, or a mixture thereof, and

f) from 80 to 99% by weight of a compound selected from the group consisting of an alkylene glycol, a polyglycol, a glycerol, and mixtures thereof.

2 . The composition as claimed in claim 1 , which further comprises up to 4% by weight of component h) selected from the group consisting of alkali metal nitrites, alkali metal amines, alkali metal phosphates, alkali metal phosphonates, alkali metal borates, alkali metal molybdates, and mixtures thereof.

3 . The composition of claim 1 , which further comprises up to 6% by weight of water.

4 . The composition of claim 2 , which further comprises up to 6% by weight of water.

5 . A mixture comprising from 5 to 90% by weight of the composition as claimed in claim 1 and from 10 to 95% by weight of water.