Heavy duty laundry detergent

Abstract: Free-flowing granular heavy duty laundry detergent is made by blending a composition to contain (i) a tert-­ amine oxide dihydrate having the formula R₁R₂R₃NO·2H₂O where R₁ is a C₈₋₂₄ alkyl, R₂ is methyl, ethyl or a C₈₋₂₄ alkyl and R₃ is methyl or ethyl, (ii) a deter­ gent builder (e.g., zeolite A) and optionally other conven­ tional laundry detergent ingredients.

Description: Trialkylamine oxides are known to be effective surfactants. Such amine oxides are made commercially by reacting a suitable trialkylamine with aqueous hydrogen peroxide. In this process the water content must be controlled to be at least 70 weight percent of the final composition or the reaction mass will gel and cannot be stirred. Such dilute aqueous solutions of trialkylamine oxide cannot be used to make a free-flowing granular laundry detergent by dry blending. Esposita et al. U. S. 4,299,739 mention the desirability of including tert-amine oxides in laundry detergents but offer no suggestion of how to tolerate the high water content. Inamorato et al. U. S. 3,489,687 describe an attempt to make a granular free-flowing laundry detergent containing an amine oxide by adding an amount of an anhydrous salt, e.g., sodium sulfate and sodium tripolyphosphate to react with all the water in the amine oxide solution to form a friable mixed hydrated salt/amine oxide composition. However this necessitates the addition of a salt composite rather than a discrete solid amine oxide. According to the present invention, free-flowing granular heavy duty laundry detergent containing a trialkylamine oxide surfactant can be made by dry mixing a detergent alkylamine oxide dihydrate with a suitable laundry detergent builder and optionally other laundry detergent components. A preferred embodiment of the invention is a free-flowing heavy duty granular laundry detergent, said laundry detergent comprising (i) 1-30 weight percent of a discrete tert-amine oxide dihydrate having the formula R₁R₂R₃NO·2H₂O wherein R₁ is a C₈₋₂₄ alkyl, R₂ is methyl, ethyl or a C₁₂₋₂₄ alkyl and R₃ is methyl or ethyl and (ii) 10-50 weight percent of a detergent builder. Another embodiment of the invention is a free-flowing heavy duty granular laundry detergent comprising 5-30 weight percent tetradecyl dimethylamine oxide dihydrate and 70-95% sodium tripolyphosphate. Further another embodiment of the invention is a free-flowing heavy duty granular laundry detergent comprising 5-30 weight percent tetradecyl dimethylamine oxide dihydrate, 5-30 weight percent sodium alkylbenzene sulfonate and 10-85 weight percent of at least one sodium carbonate and Zeolite A. An essential ingredient of the present heavy duty laundry detergent is the trialkylamine oxide dihydrate having the above formula R₁R₂R₃NO·2H₂O. Such solid tert-amine dihydrates comprise 1-50 weight percent of the detergent composition. More preferably the detergent comprises 5-30 weight percent and most preferably 10-25 weight percent of the formulation. The essential trialkylamine oxide dihydrates can be made by a process in which the appropriate amine is reacted with at least a stoichiometric amount of concentrated (e.g., 50-70 weight percent active) hydrogen peroxide in an organic ester solvent (e.g., ethyl acetate) in an amount sufficient to maintain a fluid reaction mixture. Reaction temperatures of 25-100°C can be used. A preferred range is 60-75°C. Carbon dioxide can be injected to promote the reaction. Use of 1.2 theories of 70 weight percent hydrogen peroxide results in a final reaction mixture which contains 2 moles of water per mole of amine oxide. If more water than this is present, it should be distilled out to obtain a 2/1 water/amine oxide mole ratio. The organic ester solution can then be cooled causing the amine oxide dihydrate to crystallize. Alternatively, the organic ester can be distilled out at atmospheric pressure or under vacuum to obtain the amine oxide dihydrate as the residue. It was surprisingly found that the tert-amine oxide dihydrate was not hygroscopic. A typical process for making a free flowing heavy duty granular non-hygroscopic laundry detergent comprises dry mixing 5-30 weight percent of a discrete solid non-hygroscopic tetradecyl dimethylamine oxide dihydrate, 20-80 weight percent of Zeolite A or sodium tripolyphosphate, 5-30 weight percent of a sodium C₁₀₋₁₆ alkyl benzene sulfonate and 10-60 weight percent of a sodium carbonate. Trialkylamines useful in making the tert-amine oxide dihydrate are those having the formula R₁R₂R₃N wherein R₁, R₂ and R₃ are as previously defined. Representative examples of these are: octyl dimethylamine decyl dimethylamine dodecyl dimethylamine dodecyl diethylamine tetradecyl dimethylamine hexadecyl diethylamine octadecyl dimethylamine eicosyl dimethylamine docosyl dimethylamine tetracosyl dimethylamine decyl dodecyl methylamine didodecyl ethylamine ditetradecyl methylamine dihexadecyl methylamine eicosyldecyl methylamine ditetracosyl methylamine and including mixtures thereof. Of the above, a still more preferred class of tert-amines consists of those in which R₁, is a linear C₁₂₋₂₄ primary alkyl, R₂ and R₃ are methyl. Examples of these are: n-dodecyl dimethylamine n-tetradecyl dimethylamine n-hexadecyl dimethylamine n-eicosyl dimethylamine n-docosyl dimethylamine n-tetracosyl dimethylamine and including mixtures thereof. The following Examples show how to make the required trialkylamine oxide dihydrate. Example 1 In a 250 milliliter glass reaction flask was placed 100 grams of tetradecyldimethylamine (0.41 mole; amine value 230.0 mg KOH/g amine) and 0.5 gram (1.27 mmol) of diethylenetriaminepentaacetic acid. This was heated with stirring to 65°C and then 23 grams (0.47 mole) of 70 weight percent aqueous hydrogen peroxide was added dropwise over a 15-minute period. The mixture was then heated to 76.C and stirred at that temperature for seven hours. As needed, ethyl acetate (34 mL) was added dropwise to the reaction mass in order to maintain a clear, gel-free liquid. Analysis of the crude reaction mass showed 99 percent amine conversion by proton NMR. The crude reaction mass was added to 400 mL additional ethyl acetate. The solution was then cooled to 15°C forming a non-hydroscopic white crystalline solid tetradecyldimethylamine oxide dihydrate in 86% recovered yield melting at 41°C. Example 2 In a glass reaction flask was placed 100 g tetradecyl dimethylamine and 0.5 g diethylenetriamine pentaacetic acid. Carbon dioxide sparge into the liquid phase was started and the mixture was stirred and heated to 65°C. The CO₂ sparge was stopped and a CO₂ gas phase was maintained over the reaction mixture. Dropwise feed of 70 weight percent aqueous hydrogen peroxide was started. At the same time, addition of ethyl acetate was commenced. After 10 minutes all the hydrogen peroxide and 28 mL of ethyl acetate had been added. Cooling was required to maintain the temperature under 75°C. Heat was applied and the reaction continued for two more hours. Dropwise addition of ethyl acetate was continued for the first 19 minutes of the two-hour period. Total ethyl acetate feed was 43 mL. The reaction mixture was a clear gel-free solution. The reaction mixture was analyzed by NMR showing a 100 percent amine conversion. The reaction mixture was poured into a flask containing 300 mL of ethyl acetate and cooled to 15°C. Needle-like crystals of tetradecyl dimethylamine oxide dihydrate form (106 g) indicating a 87 percent yield. The other essential ingredient in the present laundry detergent is at least one detergent builder. Detergent builders include sodium aluminum silicates (e.g. Zeolite A), sodium tripolyphosphate (STPP), sodium salt of nitrilotriacetic acid, sodium carbonate, sodium bicarbonate, sodium citrate, potassium carboxymethyloxymalonate, sodium carboxymethyloxy succinate, sodium salt of ethylenediaminetetraacetic acid (EDTA) and sodium pyrophosphate. Of the above the most preferred detergent builders are sodium carbonate, STPP and Zeolite A. The amount of builder can vary from 10 weight percent to 85 weight percent or more. A preferred amount is 20-80 weight percent and most preferably 30-50 weight percent. The laundry detergent can contain an additional surfactant other than the present tert-amine oxide dihydrate. Examples of such surfactants are anionic, nonionic, amphoteric and cationic detergents. Anionics include sodium, potassium, ammonium or alkylolammonium fatty acid soaps such as sodium salts of tallow fatty acids, coco fatty acids, oleic acid and stearic acid. Other very useful anionics are the sodium, potassium, ammonium and alkylolammonium salts of C₁₀₋₁₆ alkyl benzenesulfonic acids such as sodium tridecylbenzenesulfonate. Likewise the sodium, potassium, ammonium and alkylolammonium salts of C₁₂₋₁₆ alphaolefin sulfonates and C₁₂₋₁₆ alkylsulfates are useful. Still another class of useful anionic surfactants comprises the alkali metal alkyl glyceryl ether sulfonates such as the C₁₂₋₁₆ alkyl monoglyceride sulfonates and sulfates. Likewise the alkali metal salts of C₈₋₁₂ alkylphenyl polyethoxysulfonates and sulfates which contain 5-10 ethyleneoxy units per molecule are useful. Other useful anionics include the water-soluble salts of 2-10 alkyl esters of C₁₂₋₁₆ alpha-sulfonated fatty acids. Also water-soluble salts of 2-acyloxyalkane-1-sulfonic acid which contain 2-9 carbon atoms in the aryl group are useful. Likewise fatty alcohol sulfates and ether sulfates are effective anionic surfactants. Also C₁₂₋₁₈ alkyl polyethoxysulfates are useful co-surfactants. Useful nonionics include polyethyleneoxy (5-10 units) C₁₂₋₁₆ alcohols or C₅₋₁₀ alkylphenols. Examples are polyethoxylated (5-9 units) dodecanol and polyethoxylated (5-9 units) nonylphenol. Cationic surfactants include quaternary ammonium, phosphonium and sulfonium compounds having at least one detergent range, e.g. C₁₂₋₁₈, alkyl group such as dodecyl dimethyl ammonium chloride. Useful amphoteric surfactants include the C₁₂₋₁₈ alkyl dimethyl betaines such as hexadecyl dimethylbetaine. Other formulation components can include optical brightening agents, e.g. 4,4'-bis(triazin-2-ylamino) stilbene-2,2'-disulfonic acid, 2-(stilben-4-yl) napthotriazole, 1,4-bis(styryl)benzene and 1,3-dipenyl-2-pyrazoline. The laundry detergent may also be formulated to contain dry peroxygen bleaches, e.g., sodium perborate; bleach activators, e.g., sodium C₉ acyloxybenzenesulfonate; and anti-redeposition agents, e.g., sodium polyacrylate. Water soluble bulk fillers are routinely included in laundry detergents such as sodium sulfate. A typical laundry detergent formulation will contain 5-50 weight percent filler to aid in handling. A series of heavy duty laundry detergents formulations containing the present tert-amine oxide dihydrates is shown in the following table.

Claims: A free-flowing heavy duty granular laundry detergent, said laundry detergent comprising (i) 1-30 weight percent of a discrete tert-amine oxide dihydrate having the formula R₁R₂R₃NO·2H₂O wherein R₁ is a C₈₋₂₄ alkyl, R₂ is methyl, ethyl or a C₁₂₋₂₄ alkyl and R₃ is methyl or ethyl and (ii) 10-50 weight percent of a detergent builder. A laundry detergent of Claim 1 wherein R₂ and R₃ are methyl. A laundry detergent of Claim 1 or 2 wherein R₁ is a linear C₁₂₋₂₄ alkyl group. A laundry detergent of any of the preceding claims wherein said builder is selected from the group consisting of sodium tripolyphosphate, sodium carbonate, sodium nitrilotriacetate, sodium aluminum silicate, and mixtures thereof. A laundry detergent of any of the preceding claims which includes at least one surfactant selected from anionic surfactants, nonionic surfactants, amphoteric surfactants, cationic surfactants and mixtures thereof in addition to said tert-amine oxide dihydrate. A free-flowing heavy duty granular laundry detergent comprising: (a) 5-30 weight percent tetradecyl dimethylamine oxide dihydrate, (b) 5-30 weight percent sodium alkylbenzene sulfonate, (c) 10-85 weight percent of at least one sodium carbonate and zeolite A. A free-flowing heavy duty granular laundry detergent comprising: (a) 5-30 weight percent tetradecyl dimethylamine oxide dihydrate, (b) 70-95% sodium tripolyphosphate. A process for making a free-flowing heavy duty granular non-hygroscopic laundry detergent, said process comprising dry mixing a discrete tert-amine oxide dihydrate having the formula R₁R₂R₃NO·2H₂O wherein R₁ is a C₁₂₋₁₄ alkyl, R₂ is methyl, ethyl or a C₁₂₋₁₄ alkyl and R₃ is methyl or ethyl with conventional laundry detergent components including a detergent builder. A process of Claim 8 comprising dry mixing: (a) 5-30 weight percent of a discrete solid non-hygroscopic tetradecyl dimethylamine oxide dihydrate, (b) 20-80 weight percent of zeolite A, (c) 5-30 weight percent of a sodium C₁₀₋₁₆ alkylbenzene sulfonate and (d) 10-60 weight percent of sodium carbonate. A process of Claim 8 comprising dry mixing (a) 5-30 weight percent of a discrete solid non-hygroscopic tetradecyl dimethylamine oxide dihydrate, (b) 20-80 weight percent of sodium tripolyphosphate, (c) 5-30 weight percent of a sodium C₁₀₋₁₆ alkylbenzene sulfonate and (d) 10-60 weight percent of sodium carbonate.

Inventors: BORLAND JAMES ELLWOOD, SMITH KIM RENAE, BORLAND, JAMES ELLWOOD, SMITH, KIM RENAE
Applicants: ALBEMARLE CORP, ALBEMARLE CORPORATION
Application year: 1990
Main classification: C11D1
IPC codes: C11D11, C11D17, C11D1