Glycerin-containing antifreezing agent concentrates with corrosion protection

Abstract

The present invention relates to antifreeze/anticorrosion concentrates comprising from 10 to 50% by weight, based on the total amount of the concentrate, of glycerol, to processes for preparing such concentrates from super concentrates, to aqueous coolant compositions from these concentrates, and to their use, for example in internal combustion engines.

1 : An antifreeze/anticorrosion concentrate comprising:
 glycerol, wherein the amount of glycerol is from 15 to 35% by weight based on the total amount of the concentrate;   propylene glycol, ethers thereof or mixtures thereof as the antifreeze component, wherein the sum of the amounts of propylene glycol and glycerol is at least 75% by weight based on the total amount of the concentrate;   an anticorrosion component, wherein the amount of anticorrosion component is from 1 to 70% by weight based on the total amount of the concentrate.   
     
     
         2 : The concentrate according to  claim 1 , which additionally comprises at least one of the following components in an amount specified in each case, based on the total amount of the concentrate:
 (a) up to 5% by weight of one or more aliphatic, cycloaliphatic or aromatic monocarboxylic acids having in each case from 3 to 16 carbon atoms in the form of their alkali metal, ammonium or substituted ammonium salts;   (b) up to 5% by weight of one or more aliphatic or aromatic di- or tricarboxylic acids having in each case from 3 to 21 carbon atoms in the form of their alkali metal, ammonium or substituted ammonium salts;   (c) up to 1% by weight of one or more alkali metal borates, alkali metal phosphates, alkali metal silicates, alkali metal nitrites, alkali metal or alkaline earth metal nitrates, alkali metal molybdates or alkali metal or alkaline earth metal fluorides;   (d) up to 5 by weight of one or more aliphatic, cycloaliphatic or aromatic amines which have from 2 to 15 carbon atoms and may additionally comprise either oxygen atoms or hydroxyl groups;   (e) up to 5% by weight of one or more mono-or bicyclic, unsaturated or partly unsaturated hetrocycles which have from 4 to 10 carbon atoms and may be benzofused and/or bear additional functional groups;   (f) up to 5% by weight of one or more tetra(C 1 -C 8  alkoxy)silanes (tetra-C 1 -C 8— alkyl orthosilicates);   (g) up to 10% by weight of one or more carboxamides or sulfonamides;   (h) up to 1% by weight of one or more hard water stabilizers based on polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymers, polyvinylpyrrolidone, polyvinylimidazole, vinylpyrrolidone-vinylimidazole copolymers and/or copolymers of unsaturated carboxylic acids and olefins.   
     
     
         3 : The concentrate according to  claim 1 , wherein the pH of the concentrate is in the range from 4 to 11. 
     
     
         4 : A process for preparing an antifreeze/anticorrosion concentrate, comprising the step of:
 mixing an antifreeze superconcentrate comprising corrosion inhibitors with a glycerol component, the component comprising glycerol in an amount which results in from 15 to 35% by weight based on the total amount of the mixture in the resulting mixture and wherein the resulting mixture results in an antifreeze/anticorrosion concentrate according to  claim 1 .   
     
     
         5 : An aqueous coolant composition comprising from 10 to 90% by weight of the concentrate according to  claim 1 . 
     
     
         6 : A method of frost protection of water and simultaneously the corrosion protection by applying a coolant composition according to  claim 5  in metal casings of water-comprising vessels.