Patent GB-880524-A (GB)
Title: Polyether-carboxylic acid compounds
IPC: C07C59/125
Filed: 1957-11-07
Abstract: Lubricating compositions comprise polyether carboxytic acids each consisting of a chain of -(CH2)4-O- groups alone or in combination with other alkylene-O- groups containing 2 to 4 carbon atoms, one end of the chain terminating in an -O-R1-COOH group and the other end terminating in an -O-R2-COOH group or in an O-R3-OH group, R1 and R2 representing the same or different C1-4 alkylene groups and R3 a C2-4 alkylene group, or salts of such acids.  The polyether carboxylic acid compounds may be the sole lubricants or may be used with mineral oil or synthetic oils such as the polyether, polyether-ester and polyester oils described in Specifications 642,037, 659,103, 662,650, 666,697 and 716,339. The composition may also comprise the usual additives, such as metal soaps of stearic, hydroxystearic and oleic acids, carbon blacks, graphite, highly disperse silicic acid, copper phthalocyanine, molybdenum disulphide and bentonite.  Greases described comprise (1) a polyether co-polymer oil from tetrahydrofuran and ethylene oxide, lithium stearate and the sodium salt of a polyether carboxylic acid obtainable by the reaction of sodium cyanide with a terminally chlorinated poly-oxybutyleneoxyethylene glycol and saponification of the resulting ether-nitrile or (2) the sodium salt of a polyether carboxylic acid obtainable by oxidation with oxygen of a poly butylene glycol M.W. 750, and a poly-ester oil based on adipic acid, triethylene glycol and 2-ethyl hexanol.  The use of the potassium, lithium and neutral, basic and acidic magnesium, the alkali earth metals and aluminium salts of the polyether acids is also mentioned.ALSO:The invention comprises a polyether carboxylic acid consisting of a chain of -(CH2)4O- groups alone or in combination with other alkylene-O-groups containing from 2 to 4 carbon atoms, one end of the chain terminating in an -O-R1-COOH group and the other in an -O-R2-COOH group or an -O-R3-OH group, R1 and R2 being alkylene radicals containing 1 to 4 carbon atoms and R3 being an alkylene radical containing 2 to 4 carbon atoms, and salts of such acids. Those compounds wherein R1 and R2 are alkylene groups containing 1 to 3 carbon atoms are prepared by oxidizing at an elevated temperature with a free-oxygen containing gas, a polyalkylene glycol consisting of a chain of-(CH2)4O-groups alone or in combination with otheralkylene-O-groups containing 2 to 4 carbon atoms, or an ester thereof with a C1 to C4 carboxylic acid, saponifying the oxidation product and, if desired, liberating the polyether carboxylic acid from the salt thus obtained.  The oxidation is preferably effected in the presence of an oxidation catalyst such as a cobalt or manganese salt.  Those polyether acids in which R1, R2 and R3 represent alkylene radicals containing 2 to 4 carbon atoms may be prepared from polyalkylene glycols or C1 to C4 carboxylic acid esters thereof, in which at least one of the free or esterified hydroxy groups is replaced by halogen, the glycol consisting of a chain of -(CH2)4O-groups alone or in combination with other C2-4-alkylene-O-groups, by reacting the haloether with a hydrocyanic acid salt, preferably in the presence of an inert solvent and converting the nitrile groups in the products into carboxylic acid or carboxylic acid salt groups.  The polyether glycols used a starting materials may be prepared by polymerizing tetrahydrofuran alone or in combination with ethylene oxide, propylene oxide or 1, 2- or 2,3-butylene oxide.  Esters of the glycols may be obtained by effecting the polymerization in the presence of a C1-4 carboxylic acid anhydride and ferric chloride or perchloric acid. The polyglycols having a terminal hydroxy group replaced by halogen are obtained by effecting the polymerization in the presence of ferric chloride and acetyl chloride while the compounds wherein both hydroxyls are so replaced by halogen are obtained using ferric chloride and thionyl chloride.  Examples describe (1) the oxidation of various polybutylene glycols of M.W. 750-1000 or a poly butylene glycol diacetate, with oxygen at 155 DEG -170 DEG C., followed by caustic soda saponification in methanol yielding sodium salts of polyether carboxylic acids of acid values from 86-229, the glycol starting materials being obtained by polymerizing tetrahydrofuran in the presence of perchloric acid and acetic anhydride and when required hydrolyzing the resulting acetate, or in the presence of fluorosulphonic acid; (2) the formation of similar acids by heating a chlorine-containing co-polymer, obtained by polymerizing tetrahydrofuran with propylene oxide in the presence of thionyl chloride and ferric chloride, with sodium cyanide in ethylene glycol, hydrolyzing the resulting nitrile with aqueous NaOH, acidifying and recovering the resulting polyether acids and converting them into their salts with methanolic NaOH.  The ether acids and salts may be used as dispersing or emulsifying agents in for example the production of aqueous preparations of oils and plant protective agents.  They may also be used as or in lubricants, if desired with mineral or synthetic oils such as the polyether, -ether-ester and -ester oils described in Specifications 642,037, 659,103, 662,650, 666,697 and 716,339.  Such compositions may also comprise the usual additives such as the metal soaps of stearic, hydroxy-stearic and oleic acids, carbon black, graphite, highly dispersed silicic acid, copper phthalocyanine molybdenum disulphide and bentonite.  Greases described comprise (1) a polyether copolymer oil from tetrahydrofuran and ethylene oxide, lithium stearate and the sodium salt of a polyether acid obtained by reaction of NaCN with a terminally chlorinated poly-oxybutylene-oxyethylene glycol and saponification of the resulting ether-nitrile or (2) the sodium salt of a polyether acid obtainable by oxidation with oxygen of a polybutylene glycol M.W. 750, and a polyester oil based on adipic acid, triethylene glycol and 2-ethylhexanol.  The use of the potassium, lithium and neutral, acidic and basic magnesium, alkaline earth metal and aluminium salts of the polyether acids is also referred to.ALSO:The invention comprises a polyether carboxylic acid consisting of a chain of-(CH2)4O-groups alone or in combination with other-alkylene-O-groups containing from 2 to 4 carbon atoms, one end of the chain terminating in an-O-R-COOH group and the other in an-O-R2-COOH group or an-O-R3-OH group, R1 and R2 being alkylene radicals containing 1 to 4 carbon atoms and, R3 being an alkylene radical containing 2 to 4 carbon atoms, and salts of such acids. Those compounds wherein R1 and R2 are alkylene groups containing 1 to 3 carbon atoms are prepared by oxidising at an elevated temperature with free-oxygen containing gas, a polyalkylene glycol consisting of a chain of -(CH2)4O-groups alone or in combination with other-alkylene-O-groups containing 2 to 4 carbon atoms, or an ester thereof with a C1 to C4 carboxylic acid, saponifying the oxidation product and, if desired, liberating the polyether carboxylic acid from the salt thus obtained.  The oxidation is preferably effected in the presence of an oxidation catalyst such as a cobalt or manganese salt.  Those polyether acids in which R1, R2 and R3 represent alkylene radicals containing 2 to 4 carbon atoms may be prepared from polyalkylene glycols or C1 to C4 carboxylic acid esters thereof, in which at least one of the free or esterified hydroxy groups is replaced by halogen, the glycol consisting of a chain of-(CH2)4O-groups alone or in combination with other C2-4-alkylene-O-groups, by reacting the halo-ether with a hydrocyanic acid salt, preferably in the presence of an inert solvent, and converting the nitrile groups in the products into carboxylic acid or carboxylic acid salt groups. The polyether glycols used as starting materials may be prepared by polymerising tetrahydrofuran alone or in combination with ethylene oxide, propylene oxide or 1,2- or 2,3- butylene oxide. Esters of the glycols may be obtained by effecting the polymerisation in the presence of a C1-4 carboxylic acid anhydride and ferric chloride or perchloric acid.  The polyglycols having a terminal hydroxy group replaced by halogen are obtained by effecting the polymerisation in the presence of ferric chloride and acetyl chloride while the compounds wherein both hydroxyls are so replaced by halogen are obtained using ferric chloride and thionyl chloride.  Examples describe (1) the oxidation of various polybutylene glycols of M.W. 750-1000 or a poly butylene glycol diacetate, with oxygen at 155 DEG C. to 170 DEG C., followed by caustic soda saponification in methanol yielding sodium salts of polyether carboxylic acids of acid values from 86-229, the glycol starting materials being obtained by polymerising tetrahydrofuran in the presence of perhcloric acid and acetic anhydride and when required hydrolysing the resulting acetate, or in the presence of flurosulphonic acid; (2) the formation of similar acids by heating a chlorine-containing co-polymer, obtained by polymerising tetrahydrofuran with propylene oxide in the presence of thionyl chloride and ferric chloride, with sodium cyanide in ethylene glycol, hydrolysing the resulting nitrile with aqueous NaOH, acidifying and recovering the resulting polyether acids and converting them into their salts with methanolic NaOH.  The ether acids and their salts may be used as dispersing or emulsifying agents in, for example, the production of aqueous preparations of oils and plant protective agents.  They may also be used as or in lubricants in which connection the sodium, potassium lithium and neutral, basic and acidic magnesium, alkaline earth metal and aluminium salts of the polyether acids are mentioned (see Group III.)