GB601604A - Improvements in production of polyoxypropylene compounds - Google Patents

Abstract

Lubricant compositions comprise mixtures of liquid, water-immiscible aliphatic monoethers of polyoxypropylene glycols having a viscosity of at least 3.0 centistokes at 210 DEG F. and an average molecular weight of at least 496. They may be combined with suitable non-aqueous diluents and monoethers of different viscosities may be blended. The compositions may be used for the lubrication of the surfaces of metals, rubber, textiles and the like; in this connection, wool, cotton, flax and hemp fibres are mentioned and it is stated that in the lubrication of synthetic films the products give a more desirable "hand" to the fibre. The mixtures of monoethers are obtained by reaction of 1,2-propylene oxide with an aliphatic monohydric alcohol in the presence of an alkaline catalyst, at least 8 mols of oxide being reacted per mol of alcohol and the product stripped if necessary to give an ether having the required properties (see Group IV (b)). Examples describe products having average molecular weights of up to about 1800 obtained from propylene oxide and methanol, butanol and 7-ethyl-2-methylundecanol-4. Other alcohols mentioned are ethanol, isopropanol, 2-ethyl-butanol, hexanol, 2-ethyl-hexanol and n-octanol. The Specification as open to inspection under Sect. 91 also describes products obtained from 1,2-propylene oxide containing up to 10 per cent ethylene oxide. This subject-matter does not appear in the Specification as accepted.ALSO:Liquid, water-immiscible aliphatic monoethers of polyoxypropylene glycols are prepared by introducing 1, 2-propylene oxide substantially free of aldehydes and water into a heated liquid body of an aliphatic monohydric alcohol containing an alkaline catalyst dispersed therein and being substantially free from water, continuing the introduction of the oxide at a rate to maintain an amount of unreacted oxide at a substantially uniform concentration in the reaction mixture until at least 8 mols of the introduced oxide are reacted per mol of alcohol, thereafter if necessary stripping the resulting product of volatile materials to obtain a residue having a viscosity of at least 3 centistokes at 210 DEG F. and an average molecular weight of at least 496. The process may be carried out in a closed system at 80 DEG to 130 DEG C. under a uniform pressure of up to about 65 lbs. and in the absence of oxygen; an inert gas may be present. Generally the reaction product is treated to neutralise the catalyst and then subjected to a washing treatment to extract water-soluble impurities including low molecular weight polyoxypropylene ethers before being stripped of low boiling substances. Water or aqueous salt solution may be used as the extractant, separation of the aqueous phase being facilitated by salting out or by extracting, preferably portionwise, in the presence of a water-insoluble solvent for the desired product, for example, dichlordiethyl ether, dibutyl ether, butanol, hexanol, toluene, benzene and ethylene dichloride. Alkaline catalysts for the process are sodium, potassium and lithium hydroxides or their alcoholates; the acidic catalyst boron trifluoride is stated to promote dimerisation of the propylene oxide to dioxane and its alkyl derivatives. The propylene oxide preferably contains not more than 0.1 per cent water and this is attainable by fractional distillation of the oxide, by distillation from a hygroscopic glycol or by scrubbing with a hygroscopic liquid. The products may be used as lubricants (see Group III) for surfaces of metals, rubber, natural textile fibres and synthetic fibres, in the latter case the products serve also as finishing agents; they may also be used as hydraulic liquids. In examples: (1) n-butanol and 1,2-propylene oxide are reacted in the presence of sodium hydroxide, whereupon water is added and the catalyst neutralised, the aqueous phase separated and the residue stripped under reduced pressure yielding products of average molecular weights varying from about 540 to 1750 according to the proportions used; (2) butanol, 7-ethy-2-methyl-undecanol-4- and methanol are each reacted, in presence of sodium hydroxide, with propylene oxide which is added in stages, samples being withdrawn at each stage and worked up yielding a series of fluids having average molecular weights of up to about 1500-1800. Other alcohols specified comprise ethanol, isopropanol, 2-ethyl butanol, n-hexanol, 2-ethyl hexanol and n-octanol. The Specification as open to inspection under Sect. 91 includes the use of 1,2-propylene oxide containing up to 10 per cent ethylene oxide and is not limited to the above method of introducing the oxide nor to the above-specified minimum amount of oxide to be reacted. This subject-matter does not appear in the Specification as accepted.ALSO:Liquid, water-immiscible aliphatic monoethers of polyoxypropylene glycols are prepared by introducing 1,2-propylene oxide substantially free of aldehydes and water into a heated liquid body of an aliphatic mono-hydric alcohol containing an alkaline catalyst dispersed therein and being substantially free p from water, containing the introduction of the oxide at a rate to maintain an amount of unreacted oxide at a substantially uniform concentration in the reaction mixture until at least 8 mols. of the introduced oxide are reacted per mol. of alcohol, thereafter if necessary stripping the resulting product of volatile materials to obtain a residue having a viscosity of at least 3 centistrokes at 210 DEG F. and an average molecular weight of at least 496. The process may be carried out in a closed system at 80 DEG to 130 DEG C. under a uniform pressure of up to about 65 lbs. and in the absence of oxygen; an inert gas may be present. Generally, the reaction product is treated to neutralize the catalyst and then subjected to a washing treatment to extract water-soluble impurities including low molecular weight polyoxypropylene ethers before being stripped of low boiling substances. Water or aqueous salt solution may be used as the extractant, separation of the aqueous phase being facilitated by salting out or by extracting, preferably portionwise, in the presence of a water-insoluble solvent for the desired product, for example, dichlordiethyl ether, dibutyl ether, butanol, hexanol, toluene, benzene and ethylene dichloride. Alkaline catalysts for the process are sodium, potassium and lithium hydroxides or their alcoholates; the acidic catalyst boron trifluoride is stated to promote dimerization of the propylene oxide to dioxane and its alkyl derivatives. The propylene oxide preferably contains not more than 0.1 per cent water and this is attainable by fractional distillation of the oxide, by distillation from a hygroscopic glycol or by scrubbing with a hygroscopic liquid. The products may be used as lubricants (see Group III) for surfaces of metals, rubber, natural textile fibres and synthetic fibres, in the latter case the products serve also as finishing agents; they may also be used as hydraulic liquids. In examples: (1) n-butanol and 1,2-propylene oxide are reacted in the presence of sodium hydroxide, whereupon water is added and the catalyst neutralized, the aqueous phase separated and the residue stripped under reduced pressure yielding products of average molecular weights varying from about 540 to 1750 according to the proportions used; (2) butanol, 7 - ethyl - 2 - methyl - undecanol - 4 and methanol are each reacted, in presence of sodium hydroxide, with propylene oxide which is added in stages, samples being withdrawn at each stage and worked up yielding a series of fluids having average molecular weights of up to about 1500-1800. Other alcohols specified comprise ethanol, isopropanol, 2-ethyl butanol, n-hexanol, 2-ethyl hexanol and n-octanol. The Specification as open to inspection under Sect. 91 includes the use of 1,2-propylene oxide containing up to 10 per cent ethylene oxide and is not limited to the above method of introducing the oxide nor to the above-specified minimum amount of oxide to be reacted. This subject-matter does not appear in the Specification as accepted.