Method of reducing flock during alkoxylation

The present invention is a method for alkoxylating organic compounds, preferably polyalkylene glycols, by exposing the organic compounds to alkylene oxide vapor which is not compressed into a liquid phase for purposes of transport or introduction into the reactor. The method results in alkoxylation products containing less, little, or no flock.

A variety of organic materials react under suitable conditions with an adducting material, such as an alkylene oxide—particularly ethylene oxide or propylene oxide—to form alkoxylated organic materials. Typically, the alkylene oxide adducting material is compressed into liquid form for transport to and discharge into the reactor. Unfortunately, even if the alkylene oxide is decompressed into the vapor phase before the alkoxylation reaction begins, the previous compression of the alkylene oxide into the liquid phase tends to increase flock in the alkoxylation product. A method is needed by which to form alkoxylated products containing no, little, or less flock.

The present invention provides a method comprising contacting an organic compound adapted to be alkoxylated with an alkylene oxide in a reaction vessel under conditions effective to alkoxylate the organic compound. The alkylene oxide is maintained in vapor form before and during transport to said reaction vessel, during discharge into the reaction vessel, and during contact with the organic compound.

The present invention provides a method for producing an alkoxylation product with no, little, or less flock. According to the present method, the alkylene oxide adducting material is not compressed into liquid form in order to transport and/or to introduce the material into the alkoxylation reactor. The alkylene oxide is both transported and discharged into the reactor in the vapor phase. Without limiting the present invention to any particular theory or mechanism, it is believed that compression of ethylene oxide into the liquid phase produces minute amounts of oligomers or polymers which contribute to the formation of flock in the substrate. The present invention is believed to reduce flock by avoiding the formation of these oligomers or polymers in the alkylene oxide.

The alkoxylation reaction, itself, takes place under standard conditions. The reaction takes place at any suitable temperature, preferably from about 10° C. to about 160° C. For practical purposes, most commercial operations will be carried out in the temperature range of from about 50° C. to about 200° C.

The method is useful to alkoxylate any suitable alkoxylatable organic material. Suitable materials include, but are not necessarily limited to polyhydric, unsaturated, linear or branched alcohols, saturated alcohols, alkyl phenols, polyols, aldehydes, ketones, amines, amides, organic acids, and mercaptans. Preferred organic materials are normally selected from the group consisting of

(a) polyhydric alcohols containing a total of from about 2 to about 30 carbon atoms and having the general formula

wherein R 1 , R 2 , and R 3 independently are selected from the group consisting of linear and branched acyclic groups, alicyclic groups, aryl groups, cyclic groups, and hydrogen, and may contain one or more functional groups selected from the group consisting of amine groups, carboxyl groups, hydroxy groups, halogen atoms, nitro-groups, carbonyl groups, and amide groups. Representative but non-exhaustive examples of various polyhydric alcohols which can be alkoxylated according to the present invention are: ethylene glycol, 1,2-propylene glycol 1,4-butanediol; 1,6-hexanediol; 1,10-decanediol; 1,3-butylene glycol; diethylene glycol; diethylene glycol monobutyl ether; diethylene glycol monomethyl ether; diethyl glycol monoethyl ether, dipropylene glycol; dipropylene glycol monomethyl ether ethylene glycol monomethyl ether; ethylene glycol monoethyl ether; ethylene glycol monobutyl ether; hexylene glycol; mannitol, sorbitol; pentaerythritol; dipentaerythritol, tripentaerythritol; trimethylolpropane; trimethylolethane; neopentyl glycol; diethanolamine; triethanolamine; diisopropanolamine; triisopropanolamine; 1,4-dimethylolcyclohexane; 2,2-bis(hydroxymethyl)propionic acid; 1,2-bis(hydroxymethyl)benzene; 4,5-bis(hydroxymethyl)furfural; 4,8-bis(hydroxymethyl)tricyclo-[5,2,1,0]decane; tartaric acid; 2-ethyl-1,3-hexanediol; 2-amino-2-ethyl-1,3-propanediol; triethylene glycol; tetraethylene glycol; glycerol; ascorbic acid. Representative but non-exhaustive examples of various aldehydes and ketones which can be alkoxylated according to the present invention are lauryl aldehyde benzaldehyde; 2-undecanoneacetophenone; 2,4-pentandione; acetylsalicyclic acid; ortho-chlorobenzaldehyde; para-chlorobenzaldehyde; cinnamic aldehyde; diisobutyl ketone; ethylacetoacetate; ethyl amyl ketone; camphor; para-hydroxybenzaldehyde; 2-carboxybenzaldehyde; 4-carboxybenzaldehyde; salicylaldehyde; octyl aldehyde; decyl aldehyde; p-methoxybenzaldehyde; p-aminobenzaldehyde; phenylacetaldehyde; acetoacetic acid; 2,5-dimethoxybenzaldehyde; T-naphthyl aldehyde; terephthaldehyde;

(b) aldehydes and ketones having from about 2 to about 30 carbon atoms and having the general formula

wherein R 1 and R 2 independently are selected from the group consisting of hydrogen, linear and branched acyclic groups, alicyclic groups, cyclic groups, and aryl groups, and may contain one or more functionalities selected from the group consisting of carboxyl groups, hydroxyl groups, halogen atoms, nitro-groups, amine groups, and amide groups;

(c) primary, secondary and tertiary amides having from about 1 to about 30 carbon atoms and having the general formula

wherein R 1 , R 2 , and R 3 independently are selected from the group consisting of hydrogen, linear and branched acyclic groups, alicyclic groups, cyclic groups, and aryl groups, and may contain one or more functionalities selected from the group consisting of hydroxyl groups, carboxyl groups, carbonyl groups, amine groups, nitro-groups, and halogen atoms. Representative but non-exhaustive examples of amides which can be alkoxylated according to the instant invention are: formamide; benzamide; acetanilide, salicylamide; acetoacetanilide; ortho-acetoacetotoluidide; acrylamide; N,N-diethyltoluamide; N,N-dimethylacetamide; N,N-dimethylformamide; phthalimide; octylamide; decylamide; laurylamide; stearylamide; N,N-dimethylollaurylamide; N,N-dimethylacrylamide; para-chlorobenzamide; para-methoxybenzamide; para-aminobenzamide; para-hydroxybenzamide; ortho-nitrobenzamide,; N-acetyl-para-aminophenol; 2-chloroacetamide; oxamide; N,N-methylene-bis-acrylamide;

(d) primary, secondary, and tertiary amines having from about 1 to about 30 carbon atoms, and having the general formula

wherein R 1 , R 2 , and R 3 independently are selected from the group consisting of hydrogen, linear and branched acyclic groups, alicyclic groups, cyclic groups, and aryl groups, and may contain one or more functionalities selected from the group consisting of hydroxyl groups, carbonyl groups, halogen atoms, carboxyl groups, nitro-groups, and amide groups. Representative but non-exhaustive examples of amines which can be alkoxylated according to the present invention are: aniline; benzylamine; hexadecylamine, triphenylamine. aminoacetic acid anthranilic acid, cyclohexylamine, tert-octylamine; ortho-phenylenediamine; meta-phenylenediamine; para-phenylenediamine; N-acetyl-para-aminophenol; 2-amino-4-chlorophenol; 2-amino-2-ethyl-1,3-propanediol; ortho-aminophenol; para-aminophenol; para-aminosalicyclic acid, benzyl-N,N-dimethylamine; tert-butylamine; 2-chloro-4-aminotoluene; 6-chloro-2-aminotoluene; meta-chloroaniline; ortho-chloroaniline; para-chloroaniline; 4-chloro-2-nitroaniline; cyclohexylamine, dibutylamine; 2,5-dichloroaniline; 3,4-dichloroaniline; dicyclohexylamine; diethanolamine; N,N-diethylethanolamine; N,N-diethyl-meta-toluidine; N,N-diethylaniline; diethylenetriamine; diisopropanolamine; N,N-dimethylethanolamine; N,N-dimethylaniline; 2,4-dinitroaniline, diphenylamine, ethyl-para-aminobenzoate; N-ethylethanolamine; N-ethyl-1-naphthylamine; N-ethyl-ortho-toluidine, N-ethylaniline, ethylenediamine; hexamethylenetetraamine, 2,4-lutidine; N-methylaniline; methyl anthranilate; p,p′-diaminodiphenyl methane; ortho-nitroaniline; para-nitroaniline; tert-octylamine; piperazine; ethanolamine; isopropanolamine; ortho-toluidine; para-toluidine; 2,4-toluenediamine; triethanolamine; tributylamine; triisopropanolamine; 2,4-dimethylxylidine; para-methoxyaniline, nitrilotriacetic acid; N-phenyl-1-naphthylamine;

(e) organic acids having from about 1 to about 30 carbon atoms, and having the general formula

wherein R 1 is selected from the group consisting of hydrogen, linear and branched acyclic groups, alicyclic groups, cyclic groups, aryl groups, and may contain one or more functionalities selected from the group consisting of carbonyl groups, hydroxyl groups, halogen atoms, nitro-groups, amine groups, and amide groups. Representative but non-exhaustive examples of organic acids which can be alkoxylated according to the present invention are: formic acid; acetic acid; valeric acid; heptanoic acid; 2-ethylhexanoic acid; lauric acid; stearic acid; oleic acid; tall oil acids hydrogenated tall oil acids; benzoic acid salicyclic acid; adipic acid; azelaic acid; fumaric acid; citric acid; acrylic acid; aminoacetic acid; para-aminosalicyclic acid; anthranilic acid; butyric acid; propionic acid; ricinoleic acid; chloroacetic acid; ortho-chlorobenzoic acid; 2,4-dichlorophenoxyacetic acid; tert-decanoic acid; para-aminobenzoic acid; abietic acid; itaconic acid; lactic acid; glycolic acid; malic acid; maleic acid; cinnamic acid; para-hydroxybenzoic acid; methacrylic acid; oxalic acid; myristic acid; palmitic acid; tert-pentanoic acid; phenylacetic acid; mandelic acid; sebacic acid; tallow fatty acids; hydrogenated tallow fatty acids; tartaric acid; trichloroacetic acid; 2,4,5-trichlorophenoxyacetic acid; undecylenic acid; crotonic acid; pelargonic acid; acetoacetic acid; para-nitrobenzoic acid; ascorbic acid; nitrilotriacetic acid; naphthenic acid; 1-naphthoic acid, trimellitic acid,

(f) alkyl phenols having from about 6 to about 30 carbon atoms, and having the general formula

wherein R 1 , R 2 , R 3 , R 4 , and R 5 independently are selected from the group consisting of hydrogen, halogen atoms, hydroxyl groups, nitro-groups, carbonyl groups, linear and branched acyclic groups, alicyclic groups, cyclic groups, aryl groups, and may contain one or more functionalities selected from the group consisting of halogen atoms, ether groups, nitro-groups, carboxyl groups, carbonyl groups, amine groups, amide groups, and hydroxyl groups. Representative but non-exhaustive examples of various phenols which can be alkoxylated according to the present invention are: phenol, ortho-cresol, meta-cresol; para-cresol, 2,4-dimethylphenol 2,5-dimethylphenol; 2,6-dimethylphenol; ortho-chlorophenol; meta-chlorophenol; para-chlorophenol; para-nitrophenol; para-methoxyphenol; salicyclic acid; meta-hydroxyacetophenone; para-aminophenol; ortho-phenylphenol; nonylphenol; octylphenol; t-butyl-para-cresol; hydroquinone; catechol; resorcinol; pyrogallol, 1-naphthol, 2-naphthol; 4,4′-isopropylidenediphenol (bisphenol A); methyl salicylate; benzyl salicylate; 4-chloro-2-nitrophenol; para-t-butylphenol; 2,4-di-t-amylphenol; 2,4-dinitrophenol; para-hydroxybenzoic acid; 8-hydroxyquinoline; methyl para-hydroxybenzoate; 2-nitro-para-cresol; ortho-nitrophenol; para-phenylphenol; phenyl salicylate; salicylaldehyde; p-hydroxy benzaldehyde; 2-amino-4-chlorophenol; ortho-aminophenol; salicylamide;

(g) mercaptans of the general formula

wherein R 1 , R 2 and R 3 independently are selected from the group consisting of hydrogen, linear and branched acyclic groups, alicyclic groups, cyclic groups, and aryl groups having from about 1 to about 30 carbon atoms, and may contain one or more functionalities selected from the group consisting of carboxyl groups, hydroxyl groups, halogen atoms, nitro-groups, amine groups, and amide groups, and

(h) alcohols having the general formula ROH wherein R is selected from the group consisting of a linear and branched alkyl groups having from about 1 to about 30 carbon atoms, aryl groups, cyclic groups having from about 6 to about 30 carbon atoms, and olefinic and acetylenic groups having from about 1 to about 30 carbon atoms. Representative but non-exhaustive examples of alcohols which can be alkoxylated according to the present invention are: 1-dodecanol; 1-tridecanol; 1-tetradecanol; 1-pentadecanol; 1-hexadecanol; 1-heptadecanol; 1-octadecanol; 1-nonadecanol; 1-eicosanol; 1-docosanol; 2-methyl-1-undecanol; 2-propyl-1-nonanol; 2-butyl- 1-octanol; 2-methyl-1-tridecanol; 2-ethyl-i -dodecanol; 2-propyl- 1-undecanol; 2-butyl- 1-decanol; 2-pentyl- 1-nonanol, 2-hexyl- 1-octanol; 2-methyl-1-pentadecanol, 2-ethyl-1-tetradecanol; 2-propyl- 1-tridecanol; 2-butyl- 1-dodecanol; 2-pentyl- 1-undecanol; 2-hexyl- 1-decanol; 2-heptyl- 1-decanol; 2-hexyl- 1-nonanol; 2-octyl- 1-octanol; 2-methyl-1-heptadecanol; 2-ethyl-1-hexadecanol; 2-propyl- 1-pentadecanol; 2-butyl- 1-tetradecanol; 1-pentyl- 1-tridecanol; 2-hexyl-1-dodecanol; 2-octyl-1-decanol; 2-nonyl-1-nonanol; 2-dodecanol; 3-dodecanol; 4-dodecanol; 5-dodecanol; 6-dodecanol; 2-tetradecanol; 3-tetradecanol; 4-tetradecanol; 5-tetradecanol; 6-tetradecanol; 7-tetradecanol; 2-hexadecanol; 3-hexadecanol, 4-hexadecanol; 5-hexadecanol; 6-hexadecanol; 7-hexadecanol; 8-hexadecanol; 2-octadecanol; 3-octadecanol; 4-octadecanol; 5-octadecanol; 6-octadecanol, 7-octadecanol; 8-octadecanol; 9-octadecanol; 9-octadecenol; 2,4,6-trimethyl- 1-heptanol; 2,4,6,8-tetramethyl- 1-nonanol; 3,5,5-trimethyl- 1-hexanol; 3,5,5,7,7-pentamethyl- 1-octanol; 3-butyl- 1-nonanol; 3-butyl- 1-undecanol; 3-hexyl- 1-undecanol; 3-hexyl- 1-tridecanol; 3-octyl- 1-tridecanol 2-methyl-2-undecanol; 3-methyl-3-undecanol; 4-methyl-4-undecanol; 2-methyl-2-tridecanol; 3-methyl-3-tridecanol; 4-methyl-3-tridecanol; 4-methyl-4-tridecanol; 3-ethyl-3-decanol; 3-ethyl-3-dodecanol; 2,4,6,8-tetramethyl-2-nonanol; 2-methyl-3-undecanol; 2-methyl-4-undecanol; 4-methyl-2-undecanol; 5-methyl-2-undecanol; 4-ethyl-2-decanol; 4-ethyl-3-decanol; tetracosanol; hexacosanol; octacosanol; triacontanol; dotriacontanol; hexatriacontanol; 2-decyltetradecanol; 2-dodecylhexadecanol; 2-tetradecyloctadecanol; 2-hexadecyleicosanol, and unsaturated alcohols such as 1-hexyn-3-ol; oleyl alcohol (technically cis-9-octadecene 1-ol); 2,5-dimethyl-4-octyne-3,6-diol 2,4,7,9-tetramethyl-n-decyne-4,7-diol;, 3-dodecene-1-ol; and 3,6- dimethyl-8-dodecene- 1-ol.

While the invention is effective to alkoxylate all classes of alcohols, including but not necessarily limited to saturated and unsaturated alcohols, saturated alcohols are preferred. Of these, polyalkylene glycols are preferred, with polyethylene glycol being most preferred.

The alkoxylation reaction may be catalyzed using any suitable catalyst. Both basic and acidic catalysts may be used. Suitable catalysts include, but are not neesaily limited to: potassium hydroxide sodium hydroxide; alkylated alumfinum fluorides, alkylated aluminum halides organoaluminum zinc compounds, calcium, strontium and barium acetates and naphthanatesI BF 3 or SiF 4 and metal alkyls or metal alkoxides; and, hydrotluoric acids and metal alkoxides.

The alkoxylation may be carried out at ambient pressure or at pressures above or below ambient, as long as the alkylene oxide is maintained in the vapor phase. Normally, the pressure is from about −14 to about 30 pounds per square inch (psi). Pressures below about 20 psi are preferred. Referring to FIG. 1, in order to conduct the reaction, a suitable reactor that can hold vacuum and pressure may be modified to receive gas or vapor into the top of the reactor. The top of the stainless steel receptacle 16 containing liquid and gaseous ethylene oxide is connected with a tube, hose, or pipe 12 to the vent hole 14 on the reactor head 15. The flow of ethylene oxide gas or vapor is controlled by the valves on the tube 12. The tube 12 preferably includes a “tee” with two valves 18 so that the existing vent hole 14 on the reactor head 15 can be used both for charging ethylene oxide vapor into the reactor 10 through the tube 12 and for venting the reactor 10. A more preferred alternative is to use a reactor with a separate vent hole for venting reactor pressure. Ethylene oxide vapors are allowed to diffuse from the receptacle 16 into the reactor 10 through the tube 12. The separate vent hole is used to release residual inert atmosphere in the reactor once all of the charged ethylene oxide has reacted.

Suitable alkylene oxide adducting materials are alpha and beta alkylene oxides, preferably ethylene oxide, propylene oxide or mixtures thereof most preferably ethylene oxide. The alkoxylated product may have any desired content of the alkoxy adducting material. Where an alcohol is ethoxylated, ethylene oxide will normally comprise from about 20 to about 90 wt% of the alkoxylated product.

A suitable amount of catalyst for use in the reaction is from about 0.05 to about 10.0 weight percent catalyst based upon the weight of the total reaction mixture. Preferred levels of catalyst are from about 0.1 to about 6.0 wt% based on the total reaction mixture weight.

The invention will be better understood with reference to the following examples, which are provided to illustrate the invention, but not to limit the invention.