| 摘要 |
Hydraulic fluids comprise poly-(oxyethylene-oxy-1,2-propylene) glycol monoalkyl ethers with a content of oxypropylene groups ranging from about 20-33% by weight of total oxyalkylene groups, prepared by condensing methanol or ethanol first with ethylene oxide and then with 1,2-propylene oxide (see Division C2), optionally with known additives, e.g. anti-corrosion additives such as alkali metal salts of weak acids, fatty amines and alkanol amines and anti-oxidation additives such as phenols and aromatic nitrogen derivatives. Specified additives include n-dibutylamine, diphenylolpropane, mercaptobenzothiazole, quinol monobenzyl ether and a borax glycol condensate.ALSO:Poly - (oxyethyleneoxy - 1,2 - propylene) - glycol methyl or ethyl ethers are made by reacting 1,2-propylene oxide, preferably in the presence of an alkaline catalyst such as 0.1 to 1.0% by weight of total reagents of soda or potash at a temperature of 80-200 DEG C. and a pressure of from 5 to 10 kg. per sq. cm., with ethylene glycol methyl ether to produce a condensate having an average molecular weight of from 175-215 or with an ethylene glycol ethyl ether to produce a condensate having an average molecular weight of from 190-230, the ethylene glycol methyl ether or the ethylene glycol ethyl ether having been prepared by the reaction of ethylene oxide with methanol or of ethylene oxide with ethanol respectively and the weight ratio of the quantity of propylene oxide condensed to the quantity of ethylene oxide used to prepare the ethylene glycol ether being from 20: 80 to 33: 67 and being such that the product has the desired molecular weights. The products are used as hydraulic fluids (see Division C5). |
