ESTERS, ETHERS, AND COMPOSITIONS COMPRISING THEM

Abstract: Esters and esthers of 2,4,6-trimethylnonanol, compositions comprising them, their uses, and processes for their manufacture.

Description: "Esters, Ethers, and Compositions Comprising Them" This invention relates to esters and ethers of certain alcohols, to their uses, and to compositions comprising them. More especially, the invention relates to the use of the compounds as surfactants, synthetic lubricants or lubricant components and as plasticizers, to polymeric compositions plasticized by the esters, and to products made from the compositions. Certain of the compounds are novel. The esters of 2-ethylhexanol , especially the phthalate, are among the most commonly used plasticizers. The alcohol is obtainable by, for example, subjecting propene to hydroformylation, dimerizing the resulting butanal by the aldol reaction, a term which is used throughout this specification, including the claims, as including the subsequent dehydration to an unsaturated aldehyde, and hydrogenating the resulting aldehyde to form a saturated alcohol. The propene, produced for example by a steam cracking plant, has to be purified before hydroformylation, and its cost as feedstock is increased as a result. Although the plasticizer esters derived from 2- ethylhexanol are widely used, for some purposes, for example where a lower volatility, or a stronger solvator for the polymer is needed, higher molecular weight esters, for example those based on Cg to C 12 alcohols, are preferred. The Cg esters presently available commercially are typically derived from an isomeric mixture of Cg alcohols and the users' requirements for product consistency may result in manufacturing complexities . These complexities result from variations in feed composition and reaction conditions in the process for the manufacture of the precursors to the alcohols. These precursors may be formed for example by oligomerizing a mixed C3 to C5 olefin feed, giving a mixture of linear and branched olefins, predominantly having six to ten carbon atoms, from which is distilled a mixed C 8 olefin, which is in turn hydroformylated (oxonated) and hydrogenated to form the isomeric Cg alcohol mixture. In other commercial processes, the Cg alcohol precursors are typically obtained by di erizing butene streams and oxonating the resulting C 8 olefin fraction. The butene stream itself contains a mixture of isomers, in proportions that may vary over a period, and the cobalt oxo process causes some iso erization. Thus the alcohols resulting from hydrogenation of the aldehyde form a reaction product of variable isomer distribution together with lower and higher homologues, necessitating further treatment if customers' product specifications are to be met. The processes for making other higher alcohols differ from those used in Cg alcohol production but generally result in isomeric mixtures. In a typical commercial process for the manufacture of a plasticizer ester, the alcohol is employed in excess over the acid, and alcohol is stripped from the ester product and recycled. Because of the recycling, less reactive isomers tend to become more concentrated in the reaction vessel as the reaction progresses, resulting in a change in the composition over time. In turn, the downstream users' quality control inspection of the incoming product is more onerous than if it were a single isomer. Processing of thermoplastics containing a multi- iso er plasticizer may be more difficult to control in certain applications, resulting in a greater possibility of inconsistencies in properties between different batches of the final product. This in turn may require the user to have tighter control over process variables, e.g., oven temperature ranges in motor vehicle paintshops and flooring material lines, than would otherwise be necessary, and also complicates material recycling. Finally, effluent and environmental monitoring is more difficult; e.g. , a single isomer material may have a minimum detectability an order of magnitude lower than a multi-isomer material. There accordingly remains a need for an alternative route to commercially useful organic molecules, and more especially one that provides flexibility and a greater control of product structure, particularly the ability to produce single isomers if desired. There also remains a need for esters and ethers having enhanced properties for various uses. The present invention provides an ester or an ether of 2 , 4 , 6-trimethylnonanol. The present invention also provides a process for the manufacture of 2 , 4 , 6-trimethylnonanol, which comprises subjecting 2 , 4-dimethylheptanal to aldol condensation with propanal, and hydrogenating the resulting unsaturated aldehyde to the desired C 12 alcohol. The present invention further provides a process for the manufacture of a saturated aliphatic C 12 alcohol or an ester thereof which comprises subjecting a C 6 aldehyde to an aldol condensation with propanal to form an unsaturated C 9 aldehyde and hydrogenating the C 9 aldehyde (a) to form a saturated C 9 aldehyde, which is subjected to an aldol condensation with propanal to form a C 12 unsaturated aldehyde, which C 12 unsaturated aldehyde is hydrogenated (b) to form a saturated C 12 alcohol and, optionally, (c) esterifying the C 12 alcohol. The starting C 6 aldehyde is advantageously 2- methylpentanal, the resulting C 9 and C 12 aldehydes being the unsaturated and saturated 2 , 4-dimethylhept (en) - and (an) als, and 2 , 4 , 6-trimethylnon (en) - and (an)als. If desired, part of the unsaturated Cg aldehyde may be hydrogenated to a saturated Cg alcohol, which may also be esterified, either together with the C 12 alcohol or separately. Formation of a saturated alcohol may be carried out in two stages through a saturated aldehyde or in a single stage to the saturated alcohol, in which process the saturated aldehyde is typically formed as an intermediate and not isolated. The esters and ethers of the invention, or produced by the process of the invention, are suitable for use as solvents, paint coalescers, plasticizers, adhesives, surfactants, viscosity index improvers, synthetic lubricants, flame retardants, lubricant components, anti- wear agents, hydraulic fluids, cetane improvers, drilling fluids, thermoplastic and textile processing aids, polymer, especially vinyl chloride polymer, stabilizers, poly erizable monomers and fragrances. The acid of the ester may be inorganic or organic; if the latter, a carboxylic acid is preferred. Among organic acids, aromatic acids are preferred for plasticizer manufacture, although aliphatic acids are also employed. As examples of acids, acetic, propionic, valeric, isovaleric, n-heptanoic, n-octanoic, n-decanoic, neodecanoic, lauric, stearic, iso-stearic, oleic, erucic, succinic, phthalic (1, 2-benzenedicarboxylic) , isophthalic, terephthalic, adipic, fumaric, azelaic, 2- ethylpentanoic, 2 , 4-dimethylheptanoic, 2,4,6- trimethylnonanoic, sebacic, trimellitic, pyromellitic, acrylic, methacrylic, tall oil, naphthenic and naphthalene-type acids, carbonic, nitric, sulphuric, phosphoric and phosphorous and their thio-analogous, acids and Cg to C 13 oxo and neo acids generally may be mentioned. The esters of the C 9 and especially the C 12 alcohols with oxo and neo acids have especial utility as drilling fluids and power transmission fluids. The phosphate esters have especial utility as flame retardants while the phosphite esters provide vinyl chloride polymer stabilizers. Esters with monobasic and dibasic acids are preferred for lubricants and lubricant components; advantageously the resulting esters contain from 15 to 40 carbon atoms; adipates, azelates, and phthalates are especially preferred for lubricant manufacture. The esters with unsaturated carboxylic acids, e.g., with acrylic and methacrylic acid, provide polymerizable monomers, suitable as sole or co-monomer in thermoplastics manufacture, or in polymers used in or as adhesives, VI improvers, and coating resins. The invention accordingly also especially provides an ester of 2 , 4 , 6-trimethylnonanol with a polybasic acid, especially an ester with a dibasic acid. The invention also provides an ester of a polybasic acid in which all the acid groups are esterified by 2 , 4 , 6-trimethylnonanol, especially a dibasic acid both acid groups of which are thereby esterified. Among specific esters provided by the invention there may be mentioned, for example, 2,4,6- tri ethylnonyl acetate, the bis (2 , 4 , 6-trimethylnonyl) esters of 1, 2-benzenedicarboxylic and hexanedioic acids and the tris esters of 1, 2 , 4-benzenetricarboxylic acid, the latter providing a plasticized polymer with good electrical properties. In vinyl chloride polymer compositions, the plasticizer, especially phthalate, C 1 ester, acts as a softening aid for the polymer, a plasticized polymer (e.g. pvc) of a given hardness containing less polymer than comparable plasticized materials, prepared with other C 12 phthalate esters, thereby giving the esters of the invention an economic advantage as a result of the resulting volume cost advantage. The C 1 phthalate ester also has advantages in the manufacture of automotive sealant compositions in part because of the increased viscosity and enhanced viscosity stability of the compositions. The C 12 phthalate ester has a lower volatility than presently employed low volatility plasticizers, e.g., diisodecyl phthalate. The C 12 adipate correspondingly has a lower volatility than the presently employed commercial lubricant diisodecyl adipate, and the C 12 acetate has a lower volatility than the commercially available isodecyl acetate solvent. Both esters and ethers provide surfactants, for use, for example, in detergents, e ulsifiers, and de ulsifierε. As specific examples there may more especially be mentioned the following derivatives of 2, 4 , 6-trimethylnonanol, ROH: sulphates, ROS0 3 H, and their salts, especially sodium; sulphonates, RSO3H, and their salts, especially sodium; alkoxy sulphonates, otherwise known as ether- sulphates, for example RO(R 2 0) n S0 3 H, wherein R 2 0 represents ethoxy (EO) or propoxy (PO) and n advantageously represents from 1 to 30, preferably from 1 to 4, and their salts, especially sodium; alkoxylates, for example, those containing EO, or PO, or both groups, for example, polyethyleneglycol ethers RO(EO) m H with being, for example, from 3 to 100, more especially from 3 to 15, or poly-polyglycol ethers, RO(EO) p (PO) q H or RO(PO) q (EO) p H wherein p advantageously represents from 3 to 6 and q advantageously independently represents from 3 to 6; and ether- amines, for example, oxyalkylene wherein R 3 , R 4 and R 5 each independently represent an alkylene group, advantageously ethylene or propylene, amines, for example the example compounds of the formula ROR 3 NH 2 or ROR 4 NHR 5 NH 2 for example the oxypropylene a ine RO(CH 2 ) 3 NH 2 , diamine RO(CH 2 ) 2 NH(CH 2 )2NH2, and the nitriles (-C≡N), alkoxylates (e.g. , -N(C 2 H OH) 2 or -N(C 3 H 6 OH) 2 or quaternary ammonium salts, for example, -N(E0 or PO) CH 3 ] + X ~ , where X may represent, for example, chlorine, of the mono- or diamines. The glycidyl ether, ROCH 2 CH-CH 2 has utility m the manufacture of coating resins. The invention accordingly also provides an ether of 2 , 4 , 6-trimethylnonanol , especially a hydroxy or amino ether, more especially an polyoxyalkylene hydroxy- or amino- ether, or a derivative thereof. The ethers according to the invention may be made by methods known per se , for example as practised in the art or described in the literature. Specific examples of esters in accordance with the invention and their applications include the esters of 2 , 4 , 6-trimethylnonanol with acetic (solvent), acrylic and methacrylic (polymerizable monomer) , phthalic, adipic, sebacic, trimellitic and pyromellitic acids (plasticizer, lubricant or lubricant component for, e.g., engine oil, hydraulic fluid, refrigerant oil for hydrofluorocarbon refrigerants, fuel additive for mogas and diesel fuels). The polycarboxylic acids may be completely esterified by 2 , 4 , 6-trimethylnonanol (the C 12 alcohol), which is preferred for some applications, or may be partly esterified by the C 1 alcohol and partly by other alcohols, especially 2 , 4-dimethylheptanol and/or 2- methylpentanol . in an embodiment of the invention especially useful as lubricant or lubricant component, there is provided a mixed ester of the Cg or the C 1 alcohol if desired also in admixture with 2-methylpentanol, a polycarboxylic acid, e.g., one of those mentioned above, and a poly- hydric alcohol, the ester also optionally being derivable from a monocarboxylic acid, e.g. , one of those mentioned above. As polyhydric alcohol, there may be mentioned, more especially, one having at most six hydroxyl groups. Aliphatic alcohols are preferred, especially those with some degree of steric hindrance, examples being neopentyl glycol, pentaerythritol , dipentaerythritol , tripentaerythritol, trimethylol -ethane, -propane, and -butane, 2-ethyl-2-methyl- and 2 , 2 , -diethyl-1 , 3- propanediol and 2 , 2 , 4 , -trimethylpentane-1, 3-diol . Other preferred polyols are 2 , 2-dimethylol butane, ethylene glycol, propylene glycol, 1, 4-butanediol, sorbitol, inositol, and polyalkylene glycols (e.g., poly-ethylene, -propylene or -butylene glycol, blends thereof or copoly erized mixtures of the monomeric compounds) . Other, somewhat less preferred, examples are polyoxyalkylene glycols, other 2-substituted propanediols, and other substituted or unsubstituted butanediols, pentanediols, hexanediols, heptanediols and octanediols . The invention also provides a dihydrocarbyl dithiophosphoric acid, and a metal or ammonium dihydrocarbyl dithiophosphate, in which at least one of the hydrocarbyl groups is a 2 , 4-dimethylheptyl or a 2 , 4 , 6-trimethylnonyl group. Advantageously both hydrocarbyl groups are the specified C 9 or C 12 alkyl groups. Advantageously, the metal is zinc. The DDPA's and DDP's are made by methods known per se. The invention also provides a plasticizer composition comprising the ester of a polybasic acid and an alkanol blend comprising a major proportion of 2,4,6- trimethylnonanol and a minor proportion (up to 50%) of another alkanol or alkanols having from 6 to 12 carbon atoms, the alkanols having 6 to 12 carbon atoms including, for example, 2-methylpentanol and 2,4- dimethylheptanol . The other alkanols may be linear or branched, or mixtures thereof. If an aldehyde other than propanal is also present in the aldol reaction mixture, then a mixture of aldol products will be formed having a range of carbon atom numbers, as a result of cross-aldolization. The invention accordingly also provides the esters obtained by reaction of the resulting alcohol mixture with an acid. It will be appreciated that, where the acid is polybasic, mixed esters will be present. The invention further provides a composition comprising a plasticizer ester, or plasticizer composition, according to the invention and a polymer plasticized thereby. The invention also provides a shaped structure formed of the plasticized polymer. Advantageously, the ester is made by a process in accordance with the invention. The C 6 and Cg aldehydes required as starting materials for various aspects of the process according to the invention may be obtained as described in detail in WO 96/22268, the disclosure of which is incorporated by reference herein. That specification also contains a general description of the aldol process. The esters may be produced by methods known per se or described in the literature from the alcohol and the relevant acid or, preferably, where appropriate, the anhydride, optionally in the presence of a solvent. Elevated temperatures and reduced pressures are generally employed to drive the reaction toward completion by removal of the water produced. Catalysts may be employed. Suitable catalysts include, for example, a titanium catalyst e.g., a tetraalkyl titanate, especially tetra-iso-propyl or tetraoctyl ortho titanate, or a sulphonic acid, e.g. , p-toluene sulphonic acid or ethylsulphonic acid. Any catalyst present in the reaction product may be removed by alkali treatment and water washing. Advantageously, the alcohol is used in slight, e.g., from 10 to 25%, molar excess relative to the number of acid groups in the acid. The esters of the invention may be used as a plasticizer for numerous polymers, for example, cellulose acetate; homo- and copolymers of aromatic vinyl compounds e.g., styrene, or of vinyl esters with carboxylic acids e.g., ethylene/vinyl acetate copolymers; halogen- containing polymers, especially vinyl chloride homo- and copolymers, more especially those copolymers with vinyl esters of carboxylic acids, esters of unsaturated carboxylic acids e.g., ethacrylates, and/or olefins; nitrile rubbers; and post-chlorinated vinyl chloride polymers. Poly (vinyl chloride) is of especial interest. The proportion of plasticizer may vary within wide limits, but is generally 10 to 200 parts by weight per 100 parts of polymer, more especially 20 to 100 parts per 100. The esters of the invention may be used alone as plasticizer, or in admixture with one another, or in admixture with other plasticizers, for example, dibutyl, dipentyl, dihexyl, diheptyl, dioctyl, dinonyl, didecyl, diundecyl, didodecyl, ditridecyl phthalates, trimellitates or adipates, or butyl benzyl phthalate, or mixtures thereof. They may also or instead be used with a secondary plasticizer, e.g., a chlorinated paraffin, Texanol isobutyrate, or a processing oil. If used in admixture, it is the total proportion of plasticizer that is advantageously within the ranges given above. The plasticized polymeric compositions of the invention may be made up in numerous forms and have various end-uses. For example, they may be in the form of a dryblend, a paste, or a plastisol, depending on the grade of the resin employed. They may be used, for example, as coatings, in dipping, spraying, injection or rotational moulding, extrusion, or as self-supporting films and sheets, and may readily be foamed. End uses include flooring materials, wall coverings, moulded products, upholstery materials, leather substitutes, electrical insulation, especially wire and cable, coated fabrics, toys, and automobile parts. The invention also provides a composition comprising an ester of the invention and a refrigerant, especially a fluorocarbon refrigerant, and more especially HFC 32 (difluoromethane) or HFC 134a (1,1,1,2- tetrafluoroethane) . More especially, the invention provides such a composition also comprising at least one of a hydrolytic stability enhancer, e.g., a hindered phenol or an aromatic amine, an antioxidant, corrosion inhibitor, and a metal deactivator.

Claims: CLAIMS : 1. An ester of 2 , 4 , 6-trimethylnonanol. 2. An ester as claimed in claim 1, derivable from an inorganic acid. 3. An ester as claimed in claim 1, derivable from an organic acid. 4. An ester as claimed in claim 3, wherein the acid is a monocarboxylic acid. 5. An ester as claimed in claim 4, wherein the acid is acetic, acrylic, or methacrylic acid. 6. An ester as claimed in claim 3, wherein the acid is a polycarboxylic acid. 7. An ester as claimed in claim 6, wherein the acid is phthalic, adipic, or tri ellitic acid. 8. An ester as claimed in claim 6 or claim 7, wherein each carboxyl group of the acid is esterified by the specified C 12 alcohol. 9. An ester as claimed in claim 6 or claim 7, wherein at least one carboxyl group of the acid is esterified by an alcohol other than the specified C 12 alcohol. 10. An ester as claimed in claim 9, wherein at least one carboxyl group is esterified by 2- ethylpentanol or 2 , 4-dimethylheptanol. 11. A complex ester of 2 , 4 , 6-trimethylnonanol or 2 ,4-dimethylheptanol, a polyol, and a polycarboxylic acid. 12. An ester as claimed in claim 11, wherein the polyol is neopentyl glycol, pentaerythritol, dipentaerythritol, trimethylolethane, or trimethylolpropane. 13. An ester as claimed in claim 11 or claim 12, also derived from a monocarboxylic acid. 14. An ester as claimed in any one of claims 11 to 13, which is also derived from 2-methylpentanol. 15. A plasticizer composition comprising an ester as claimed in any one of claims 6 to 14. 16. A plasticized polymeric composition, or a shaped structure thereof, comprising a thermoplastic polymer and an ester or plasticizer composition as claimed in any one of claims 6 to 15. 17. A composition comprising a refrigerant and an ester as claimed in any one of claims 3 to 14. 18. A composition as claimed in claim 17, wherein the refrigerant is a fluorocarbon refrigerant. 19. A composition as claimed in claim 18, which comprises HFC " 32 or HFC 134a. 20. A composition as claimed in any one of claims 17 to 19, which also comprises at least one of a hydrolytic stability enhancer, an antioxidant, corrosion inhibitor, and a metal deactivator. 21. A dihydrocarbyl dithiophosphoric acid, or a metal or ammonium dihydrocarbyl dithiophosphate, in which at least one of the hydrocarbyl groups is a 2,4- dimethylheptyl or a 2 , 4 , 6-trimethylnonyl group. 22. A compound as claimed in claim 21, wherein both hydrocarbyl groups are 2, 4-dimethyl or 2,4,6- tri ethylnonyl groups. 23. A zinc dihydrocarbyl dithiophosphate, at least one hydrocarbyl group of which is a 2,4-dimethyl or a 2 , 4 , 6-trimethylnonyl group. 24. A process for the manufacture of 2,4,6- trimethylnonanol, which comprises subjecting 2,4- dimethylheptanal to aldol condensation with propanal, and hydrogenating the resulting unsaturated aldehyde to the desired C 12 alcohol. 25. A process as claimed in claim 24, wherein the desired C 12 alcohol is esterified. 26. A process for the manufacture of a saturated aliphatic C 12 alcohol or an ester thereof which comprises subjecting a C 6 aldehyde to an aldol condensation with propanal to form an unsaturated Cg aldehyde and hydrogenating the Cg aldehyde (a) to form a saturated C 9 aldehyde, which is subjected to an aldol condensation with propanal to form a C 12 unsaturated aldehyde, which C 12 unsaturated aldehyde is hydrogenated (b) to form a saturated C 1 alcohol and, optionally, (c) esterifying the C 12 alcohol. 27. A process as claimed in claim 26, wherein a portion of unsaturated C 9 aldehyde is hydrogenated to a saturated Cg alcohol, which is subsequently esterified together with the C 12 alcohol or separately. 28. A process as claimed in any one of claims 25 to 27, wherein the ester formed is as defined in any one of claims 2 to 14. 29. The use of an ester as specified in any one of claims 6 to 14 as a lubricant or lubricant component. 30. 2,4, 6-trimethylnonanyl sulphate. 31. 2 ,4, 6-trimethylnonanyl sulphonate. 32. An alkoxy sulphate of 2 , 4 , 6-trimethyl- nonanol. 33. A compound as claimed in claim 32, of the formula R0(R 2 0) n 0S0 3 H, wherein R represents 2,4,6- trimethylnonanyl, R 2 0 represents ethoxy(EO) or propoxy(PO) and n represents from 1 to 4. 34. A salt of a compound as claimed in any one of claims 30 to 33. 35. An ether of 2 , 4 , 6-trimethylnonanol. 36. A compound of the formula RO(R 2 0) m H, wherein R and R 2 are as defined in claim 33 and m represents from 3 to 15. 37. A compound of the formula R0(E0) p (P0) q H or RO(PO)q(EO) p H wherein R, EO and PO are as defined in claim 33 and p and q independently represent from 3 to 6. 38. A compound of the formula R0R 3 NH or ROR 4 NHR 5 NH 2 wherein R is as defined in claim 33 and R 3 , R 4 , and R 5 represent an alkylene group. 39. A nitrile, alkoxylate, or quaternary ammonium salt of a compound as claimed in claim 38. 40. A surfactant composition comprising a compound as defined in any one of claims 30 to 39. 41. A compound as claimed in claim 2, wherein the acid is phosphoric acid. 42. A flame retardant composition containing a compound of claim 41. 43. A compound as claimed in claim 2, wherein the acid is phosphorous acid. 44. A vinyl chloride stabilizing composition comprising a compound of claim 43. 45. The glycidyl ether of 2 , 4 , 6-trimethyl- nonanol.

Inventors: CAERS RAPHAEL FRANS IVO, SCHLOSBERG RICHARD HENRY, CAERS, RAPHAEL, FRANS, IVO, SCHLOSBERG, RICHARD, HENRY
Applicants: CAERS RAPHAEL FRANS IVO, EXXON CHEMICAL LTD, EXXON CHEMICAL PATENTS INC, SCHLOSBERG RICHARD HENRY, CAERS, RAPHAEL, FRANS, IVO, EXXON CHEMICAL LIMITED, EXXON CHEMICAL PATENTS, INC., SCHLOSBERG, RICHARD, HENRY
Application year: 1997
Main classification: C07C69
IPC codes: C07C43, C07C45, C07C69, C07C305, C07D303, C07F9, C09K5, C09K8, C09K21, C10M105, C10M171