Cleaner for automotive engine cooling system

Abstract

Abstract A cleaner to be used preferably in conjunction with conventional glycol-type collants in automotive cooling systems and methods of using same. The present cleaners may be referred to as extended-life cleaners which may be added to the glycol coolant and are co-extensive with the life of said glycol. These cleaners operate to dissolve deposits, minimize corrosion damage, and dissolve organic degradation products, all of which cause heat transfer difficulties. The basic cleaner comprises: A. an aminopolycarboxylic acid B. an α hydroxy acid such as gluconic, tartaric, or citric C. an azole copper protector such as mercaptobenzothiazole (MBT) and a monoaryl triazole such as benzotriazole or tolyltriazole Wherein the above components are combined in a weight ratio ranging from 3:1:1 to 2:1:1. An aqueous concentrate is preferred and in such a concentrate the amount of Deposit Release Agent varies from about 85-15% with a more preferred range being an aqueous concentrate which contains from 50-15% by weight of the Deposit Release Agent. The balance of such concentrate is, of course, water, preferably soft water. The aqueous concentrates above are adjusted with the water-soluble basic material to give a pH of about 7.5-12.6 with a preferred pH 7.5-10.6. In addition to the Deposit Release Agent noted above, the following components are necessary in some of the cleaner formulations of this invention. 1. In order to emulsify in water, an oil-in-water emulsifying agent is utilized, such as Triton CF 10 (Rohm and Haas), an ethoxylated nonylphenol with an average of 9 EtO. 2. a reducing agent to reduce iron from Fe + + + to Fe + + is also present and a preferred reducing agent is thioglycolic acid or one of its soluble alkali metal salts. 3. Also present in some of the cleaner compositions is a polymeric dispersant which may be a water-soluble carboxylic acid polymer, a vinyl addition polymer, or carboxymethyl cellulose. A preferred polymer is the copolymer of styrene maleic anhydride and these polymers have a molecular weight of 1,000 to 1,000,000 and preferably 100,000 or less. 4. As a brightener or film former for solder an aminoalkanol is utilized preferably diethylaminoethanol. Additionally, a minor quantity of antifoams and dyes may be used in an optional manner as indicated.

Inventors

• 👤 Alfred W. Oberhofer
• 👤 James J. Benko
• 👤 Joseph C. Drozd

Bibliographic Details