Patent GB-780977-A (GB)
Title: Process for preparing formals suitable for use as synthetic lubricants
IPC: A23L2/46
Filed: 1954-03-30
Abstract: Lubricating compositions comprise formals of the general formula AOCH2OB wherein A and B represent residues of aliphatic compounds containing hydroxyl groups, the formals having between 20 and 130 carbon atoms and preferably having an ASTM pour point below 35 DEG F., a flash point above 300 DEG  F. and a kinematic viscosity at 210 DEG  F. between 2 and 60 centistokes.  The formals may be used as lubricants in conjunction with the usual additives such as viscosity index improvers and oxidation inhibitors or may be blended with other lubricants, natural or synthetic, e.g. diesters of dicarboxylic acids or complex esters. The formals or their blends with other lubricants may be thickened with grease-forming soaps such as the alkali or alkaline earth metal soaps of oleic, stearic, ricinoleic and fatty oil acids.  The formals may be simple or mixed formals of monohydroxy aliphatic compounds, polyformals of monohydroxy compounds with polyhydroxy compounds and complex formals such as those of the general formul  [AOCH2O(CnH2nOy]2CH2 and AO[CH2O(CnH2nO)y]2CH2, wherein A and B are the aliphatic residues from C1 to C60 aliphatic hydroxy compounds and n and y are integers, n being at least 2. Typical formals are the bis-(tridecoxy methyl) ether of ethylene glycol, tridecyl tridecoxy methoxy lactate, methyl lauroxymethyl polypropylene ether glycollate and the formals <FORM:0780977/III/1> and <FORM:0780977/III/2> Their preparation is given (see Group IV (b)).  Specificatio 732,086 is referred to.  Reference has been directed by the Comptroller to Specification 523,396.ALSO:Formals having 20-130 carbon atoms and containing only carbon, hydrogen and oxygen in the molecule are prepared by specified methods using aliphatic alcoholic-hydroxy compounds and aliphatic chloro-methyl ethers as starting materials.  In one method, a molar proportion of a chloromethyl ether R(OCH2Cl)x, where R represents an aliphatic organic group derived from an aliphatic compound containing x hydroxy groups, x being 1 or more, is reacted with approximately x molar proportions of a second aliphatic compound having a single hydroxy group.  In a second method, a chloromethyl ether of an aliphatic compound containing a single hydroxy group is reacted with an aliphatic compound containing a plurality of hydroxy groups, there being used approximately as many molar proportions of the first reagent as there are hydroxy groups in the second reagent.  A third method comprises reacting a chloromethyl ether of a C1 to C60 aliphatic compound having an alcoholic hydroxy group with a glycol HO(CnH2nO)yH to form a hydroxy formal and either reacting the hydroxy formal with formaldehyde to give a formal of the general formula [AOCH2O(CnH2nO)y]2CH2, wherein A is the residue of the C1 to C60 organic compound and y and n are integers, n being at least 2, or reacting the hydroxy formal, of formula AOCH2O(CnH2nO)yH, with a chloromethyl ether of a second hydroxy formal of formula BOCH2O(CnH2nO)yH to produce a formal of the formula AO[CH2O(CnH2nO)y]2-CH2OB, where n and y are as above defined and A and B are residues of C1 to C60 aliphatic compounds having an alcoholic hydroxy group.  In each method, the reaction with the chloromethyl ether is effected at between 30 DEG  and 230 DEG  C. for 1-60 hours, and the reagents are so selected that the final products contain the required carbon content and only the elements carbon, hydrogen and oxygen.  The hydrogen chloride liberated in the reaction may be removed by blowing with an inert gas, distilling with a low-boiling hydrocarbon or by means of a basic substance such as a tertiary amine or a sodium alcoholate of the hydroxy reagent.  The formals may be used as lubricants (see Group III) or as solutizers or plasticisers.  In examples: (1) bis-chloromethyl ethylene glycol is reacted with 2 molar proportions of tridecyl oxo ether is reacted with one mole of "Lorol" (Registered Trade Mark) B alcohol; (3) tridecyl glycollate is prepared from C13 oxo alcohols and reacted with C13 oxo alcohol chloromethyl ether (1 mol.); (4) tridecyl lactate is prepared and used as in (3); (5) methyl glycollate is reacted with propylene oxide using a BF3-ether complex as catalyst and the condensate containing 12,7 oxypropylene units per molecule (average) is reacted with lauryl chloromethyl ether; (6)-(11) two mols. of the chloromethyl ether of C8 or C10 oxo alcohol is reacted with tetramethylene glycol, tetraethylene glycol or tripropylene glycol; (12) C10 oxo alcohol chloromethyl ether (4 mols.) is reacted with pentaerythritol or (13) two mols. of the same ether is reacted with nonane diol; (14) tripropylene glycol (2 mols.) is reacted with one mol. of a bischloromethyl ether, obtained from tripropylene glycol, paraformaldehyde and HCl, and the product is reacted with 2 mols. of a C13 oxo alcohol chloromethyl ether yielding the formal C13H27OCH2O[(C3H6O)3 CH2O]3C13H27; (15) triethylene glycol is reacted with paraformaldehyde in hexane using NaHSO4 as catalyst and the formal solution so obtained is reacted with C10 oxo alcohol chloromethyl ether yielding the formal C10H21OCH2O[(CH2 CH2O]3C10H2. The products are normally washed and then stripped under reduced pressure.  Solvent extraction methods may also be used in the separation of the products.  Thus, polyethylene glycol 400 reacted with a mol. of C13 oxo alcohol chloromethyl ether yields a mixture of the mono- and bis formals of the glycol and unchanged glycol; extraction with hexane removes the bis-formal and diethyl ether removes the mono-formal.  Further examples of starting materials for use in the preparation of formals include glycerol, sorbitol, esters of hydroxy valeric and hydroxy stearic acids, condensates of such esters or of alcohols with ethylene, propylene or other alkylene oxides and the appropriate aliphatic reagents listed in Specification 732,086.  Chloromethyl ethers specified above as reagents are prepared by reacting the alcohols with formaldehyde and gaseous HCl; other methods referred to are the chlorination of methyl ether and the reaction of formals with formaldehyde and HCl.  Reference has been directed by the Comptroller to Specification 523,396, [Group IV].