Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/66—Non-ionic compounds
  • C11D1/83—Mixtures of non-ionic with anionic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D11/00—Special methods for preparing compositions containing mixtures of detergents
  • C11D11/04—Special methods for preparing compositions containing mixtures of detergents by chemical means, e.g. by sulfonating in the presence of other compounding ingredients followed by neutralising
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
  • C11D1/12—Sulfonic acids or sulfuric acid esters; Salts thereof
  • C11D1/29—Sulfates of polyoxyalkylene ethers
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/66—Non-ionic compounds
  • C11D1/72—Ethers of polyoxyalkylene glycols

Definitions

• This invention relates to liquid surface active compositions comprising a mixture of alcohol ethoxylates and alcohol ethoxysulfates which have high active matter content and contain low levels of 1,4-dioxane.
• Liquid surfactant compositions are well known in the field of laundry detergents and, whether for domestic or industrial applications, practically all of the available formulations are solutions of one or more surface active materials (surfactants) in water, together with an organic solvent if necessary. Such formulations usually contain only about 10 wt% to 45 wt% active matter.
• alcohol ethoxysulfates are finding increasing use in household laundry powders and liquids as part of mixed active surfactant systems.
• a drawback to the use of alcohol ethoxysulfates in detergent formulations is the formation of 1,4-dioxane, an undesirable side-product during SO3 sulfation of alcohol ethoxylates to produce alcohol ethoxysulfate.
• 1,4-dioxane has become progressively linked to carcinogenic activity, thus leading to a need to define acceptable levels of 1,4-dioxane and to develop a method for lowering the level of 1,4-dioxane in alcohol ethoxysulfate to an acceptable level or eliminating it altogether.
• dioxane levels in aqueous alcohol ethoxysulfate solutions can be reduced by sulfating at less than the stoichiometric ratio of SO3 to alcohol ethoxylate feed.
• It is therefore an object of this invention to prepare surface active compositions comprising a blend of alcohol ethoxylates and alcohol ethoxysulfates with a 1,4-dioxane content of less than 10 ppm relative to alcohol ethoxysulfate, less than 15% water and substantially free of any organic solvent.
• an anionic surfactant, alcohol ethoxysulfate is prepared by partial sulfation and blended with a nonionic surfactant, alcohol ethoxylate.
• Each of these surfactant types act as mutual hydrotropes, thereby permitting liquid concentrates containing active matter levels of at least 85%.
• This invention relates to a process for preparing a liquid surface active composition having a 1,4-dioxane content of less than 10 ppm relative to alcohol ethoxysulfate which process comprises: a) partially sulfating an alcohol ethoxylate at an SO3/alcohol ethoxylate mole ratio of less than 0.99 to form a mixture of a sulfuric acid ester of said alcohol ethoxylate and alcohol ethoxylate and b) combining said mixture with a concentrated base in an amount sufficient to neutralize said sulfuric acid ester, and an amount of alcohol ethoxylate and water sufficient to yield a final composition having from 15 percent by weight to 99 percent by weight of an alcohol ethoxylate, from 1 percent by weight to 80 percent by weight of a salt of an alcohol ethoxysulfate, and from .01 percent by weight to 15 percent by weight water, wherein said alcohol ethoxylate and alcohol ethoxysulfate components comprise at least 85 percent by weight of said composition,
• This invention also relates to liquid surface active compositions prepared according to this process.
• the SO3/alcohol ethoxylate mol ratio is less than 0.90.
• the composition prepared in the instant process thus comprises a) an alcohol ethoxylate component, b) an alcohol ethoxysulfate component prepared by partial sulfation of an alcohol ethoxylate and c) less than 15 percent by weight of water, with the alcohol ethoxylate and alcohol ethoxysulfate components together comprising at least 85 percent by weight of the composition.
• the composition is also substantially free of organic solvents, particularly low molecular weight organic solvents and more particularly, lower alcohols having from 1 to about 5 carbon atoms, particularly ethanol and methanol.
• liquid shall mean a pourable material which is neither a solid nor a gel.
• substantially free of an organic solvent shall mean that the amount of organic solvent present, if any, is less than the amount which would substantially alter the properties of the composition.
• the composition typically contains less than about 3 percent by weight of organic solvent, per total weight of the composition.
• the general class of nonionic surfactants or alcohol ethoxylates which are partially sulfated in the process of the instant invention and which are combined with the alcohol ethoxysulfate to form the final liquid surfactant composition is characterized by the chemical formula R-O-(CH2-CH2O) n -H (I) wherein R is a straight-chain or branched-chain alkyl group having in the range of from 8 to 18 carbon atoms, preferably from 12 to 18 carbon atoms, or an alkylaryl group having an alkyl moiety having from 8 to 12 carbon atoms, and n represents the average number of oxyethylene groups per molecule and is in the range of from 1 to 12, preferably from 2 to 9 and more preferably from 2 to 5.
• the alkyl group can have a carbon chain which is straight or branched, and the ethoxylate component can be a combination of straight-chain and branched molecules.
• the ethoxylate component can be a combination of straight-chain and branched molecules.
• about 85 percent of the R groups in the alcohol ethoxylates utilized in the instant invention are straight-chain.
• Ethoxylates within this class are conventionally prepared by the sequential addition of ethylene oxide to the corresponding alcohol (ROH) in the presence of a catalyst.
• the alcohol ethoxylates utilized in the instant invention are preferably derived by ethoxylation of primary or secondary, straight-chain or branched alcohols.
• the most common ethoxylates in this class and the ones which are particularly useful in this invention are the primary alcohol ethoxylates, i.e., compounds of formula I in which R is an alkyl group and the -O-(CH2-CH2O) n -H ether substituent is bound to a primary carbon of the alkyl group.
• Alcohols which are suitable for ethoxylation to form the alcohol ethoxylate component of the surfactant composition as well as the alcohol ethoxylate to be partially sulfated in this invention include coconut fatty alcohols, tallow fatty alcohols, and the commercially available synthetic long-chain fatty alcohol blends, e.g., the C12 to C15 alcohol blends available as NEODOL 25 Alcohol (a registered trademark of product manufactured and sold by Shell Chemical Company), the C12 to C14 alcohol blends available as Tergitol 24L (a registered trademark of product manufactured and sold by Union Carbide Corporation), and the C12 to C13 alcohol blends available, for example, as NEODOL 23 Alcohol (Shell).
• NEODOL 25 Alcohol a registered trademark of product manufactured and sold by Shell Chemical Company
• Tergitol 24L a registered trademark of product manufactured and sold by Union Carbide Corporation
• C12 to C13 alcohol blends available, for example, as NEODOL 23 Alcohol (Shell).
• Suitable alcohol ethoxylates can be prepared by adding to the alcohol or mixture of alcohols to be ethoxylated a calculated amount, e.g., from 0.1 percent by weight to 0.6 percent by weight of a strong base, typically an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide or potassium hydroxide, which serves as a catalyst for ethoxylation.
• a strong base typically an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide or potassium hydroxide, which serves as a catalyst for ethoxylation.
• the resulting mixture is dried, as by vapor phase removal of any water present, and an amount of ethylene oxide calculated to provide from 1 mole to 12 moles of ethylene oxide per mole of alcohol is then introduced and the resulting mixture is allowed to react until the ethylene oxide is consumed, the course of the reaction being followed by the decrease in reaction pressure.
• nonionic detergent active compounds which can be used in the present invention as the feedstock for the partial sulfation step or as the alcohol ethoxylate component of the surfactant composition include ethoxylated fatty alcohols.
• a preferred class of nonionic ethoxylates is represented by the condensation product of a fatty alcohol having from 12 to 15 carbon atoms and from 2 to 9 moles of ethylene oxide per mole of fatty alcohol.
• Suitable species of this class of ethoxylates include: the condensation product of one mole of a C12-C15 oxo-alcohol and 7 moles of ethylene oxide; the condensation product of one mole of a narrow cut C14-C15 oxo-alcohol and 7 or 9 moles of ethylene oxide; the condensation product of one mole of a narrow cut C12-C13 fatty oxo-alcohol and 6.5 moles of ethylene oxide.
• the fatty oxo-alcohols while primarily linear, can have, depending upon the processing conditions and raw material olefins, a certain degree of branching.
• a degree of branching in the range from 15% to 50% by weight is frequently found in commercially available oxo-alcohols.
• an alcohol ethoxylate as described above is sulfated under conditions to maintain a predetermined proportion of sulfated alcohol ethoxylate in the product.
• the alcohol ethoxylate is thus only partially sulfated and a mixture of a sulfuric acid ester of the alcohol ethoxylate and alcohol ethoxylate is formed.
• the partial sulfation in the instant invention is carried out utilizing liquid or gaseous SO3 as a sulfating agent in a molar ratio of SO3 to alcohol ethoxylate in the range of from 0.50 to 0.99, preferably 0.60 to 0.95 and more preferably from 0.60 to 0.90, in order to achieve a final liquid surfactant composition containing less than about 10 ppm 1,4-dioxane relative to alcohol ethoxysulfate.
• the partial sulfation reaction may be carried out employing either batch or continuous operations, and the specific reaction times and temperatures may be varied depending upon the reaction system utilized. Suitable partial sulfation agents include sulfur trioxide (SO3).
• a typical partial sulfation procedure utilizing sulfur trioxide includes contacting liquid alcohol ethoxylate and gaseous sulfur trioxide at a molar ratio of SO3 to alcohol ethoxylate in the range of from about 0.60 to about 0.90 at about atmospheric pressure in the reaction zone of a falling film sulfator cooled by water at a temperature in the range of from about 25°C to about 70°C to yield a mixture of the sulfuric acid ester of alcohol ethoxylate and unsulfated alcohol ethoxylate.
• the alcohol ethoxysulfates produced by the partial sulfation in step a) of the instant process are characterized by the chemical formula R′-O-(CH2-CH2O) x -SO3M (I) wherein R′ is a straight-chain or branched-chain alkyl group having in the range of from 8 to 18 carbon atoms, preferably from 12 to 18 carbon atoms, or an alkylaryl group having an alkyl moiety having from 8 to 12 carbon atoms, x represents the average number of oxyethylene groups per molecule and is in the range of from 1 to 12, preferably from 5 to 12 and more preferably from 7 to 12 and M is a cation selected from an alkali metal ion, an ammonium ion, and mixtures thereof.
• R′ is preferably substantially straight-chain alkyl, that is, at least 50 percent, preferably 85 percent, of the alkyl R′ groups in the instant composition are straight-chain.
• the sulfuric acid ester of the alcohol ethoxylate formed during partial sulfation exits from the falling film column and is combined in step b) with a neutralizing agent sufficient to neutralize the sulfuric acid ester, and an amount of alcohol ethoxylate and water.
• the alcohol ethoxylate which is combined with the alcohol ethoxysulfate can be the unsulfated alcohol ethoxylate product from the partial sulfation step, an additional alcohol ethoxylate which may or may not contain the same number of oxyethylene units per molecule as the alcohol ethoxylate which is partially sulfated, or a combination of the two.
• the alcohol ethoxylate which is partially sulfated in step a) to form the alcohol ethoxysulfate component of the liquid surfactant composition has a higher average number of oxyethylene units per molecule than the alcohol ethoxylate which is combined with the alcohol ethoxysulfate in step b).
• the amount of alcohol ethoxysulfate which is present in the final surfactant composition is in the range of from 1 percent by weight to 80 percent by weight, preferably from 25 percent by weight to 75 percent by weight, and more preferably from 40 percent by weight to 60 percent by weight.
• the amount of alcohol ethoxylate which is present in the final composition of the present invention is in the range of from 15 percent by weight to 99 percent by weight, preferably from 25 percent by weight to 75 percent by weight, and more preferably from 40 percent by weight to 60 percent by weight.
• the weight ratio of alcohol ethoxylate to alcohol ethoxysulfate in the composition prepared by the process in the instant invention can vary widely with weight ratios in the range of from 99:1 to 1:6, from 5:1 to 1:5, from 4:1 to 1:4 and from 3:1 to 1:3.
• the weight ratio of alcohol ethoxylate to alcohol ethoxysulfate is preferably in the range of from 4:1 to 1:4, preferably from 3:1 to 1:3, and more preferably from 2:1 to 1:2.
• the amount of water utilized in the composition is less than 15 percent by weight of the composition, preferably less than 10 percent by weight, more preferably less than 7 percent by weight, and most preferably, less than 5 percent by weight.
• the amount of water can be controlled most efficiently when an anhydrous base, such as for example, triethanolamine or monoethanolamine, is used as the neutralizing agent in step b) of the process.
• an anhydrous base such as for example, triethanolamine or monoethanolamine
• the amount of water can also be controlled in systems prepared with alkali metal neutralizing agents such as, for example, sodium and potassium hydroxide.
• step b) of the sulfuric acid ester of the alcohol ethoxylate prepared by the partial sulfation in step a) with the neutralizing agent, alcohol ethoxylate and water can be accomplished by mixing the components together in any manner. It is generally preferred, however, that the unneutralized alcohol ethoxysulfate product of step a) (i.e., the organic sulfuric acid ester/unreacted alcohol ethoxylate mixture resulting from the partial sulfation reaction) be added to a well-stirred mixture of alcohol ethoxylate and a concentrated base such as, for example, aqueous 50% sodium hydroxide.
• suitable bases include potassium hydroxide, ammonium hydroxide, triethanolamine and monoethanolamine.
• the liquid compositions prepared according to the process in the instant invention have a surface active material content, i.e. the percentage of alcohol ethoxylate plus the percentage of alcohol ethoxysulfate, of at least 85 percent by weight, preferably at least 90 percent by weight, and more preferably, at least 95 percent by weight of said composition.
• the compositions are also substantially free, typically less than 3 percent by weight, of organic solvents, preferably alcoholic solvents and more preferably, lower alcoholic solvents having from 1 to 5 carbon atoms.
• liquid surfactant compositions prepared in the invention can be utilized in a variety of detergent applications.
• the liquid surfactant compositions can be blended at relatively low temperatures, about 60°C or less, with solid detergent materials such as, for example, sodium carbonate, in order to form mixed active dry detergent powders.
• the liquid surfactant composition can also be added to water to form liquid detergents having lower active matter concentrations.
• An alcohol ethoxylate with a C12-C13 alkyl group and containing an average of 6.5 moles ethylene oxide/mole alcohol (commercially available as NEODOL 23-6.5 alcohol ethoxylate) was sulfated by reaction with gaseous SO3 in a lab-scale falling-film reactor to form an alcohol ethoxysulfate.
• the SO3/ethoxylate mole ratio was 0.64, and the reactor temperature was 65°C.
• the acid product was prepared at a rate of 13 g/min and was directly neutralized in a pre-mixed solution containing 42 g aqueous 50% sodium hydroxide and 67 g of an alcohol ethoxylate with a C12-C13 alkyl group and containing an average of 6.5 moles ethylene oxide/mole alcohol.
• the surfactant mixture was kept well-stirred through the use of a magnetic stirring plate. No gel formation was observed throughout the process. Approximately 420 g of acid product from the sulfator were added until pH 8 was obtained as measured by moistened pH paper.
• the final product was a clear flowable liquid at 20°C and had the analyzed composition presented in Table I.
• Surfactant Composition A was used except that the SO3/ethoxylate mole ratio was held at 0.83. Approximately 300 g of the acid product were neutralized in a pre-mixed solution containing 42 g aqueous 50% sodium hydroxide and 189 g NEODOL 23-6.5 alcohol ethoxylate.
• the final product was a clear flowable liquid at 20°C and had the analyzed composition presented in Table I.
• Surfactant Composition A The procedure described for Surfactant Composition A above was used except that the SO3/ethoxylate mole ratio was held at 1.03. Approximately 240 g of the acid product were neutralized in a pre-mixed solution containing 42 g aqueous sodium hydroxide and 250 g NEODOL 23-6.5 alcohol ethoxylate. The final product was a clear flowable liquid at 20°C and had the analyzed composition given in Table I.
• Surfactant Compositions A, B, and C were found to be quite comparable. All three were single-phase pumpable liquids of relatively low viscosity despite containing at least 50% alcohol ethoxysulfate and greater than 95% total surfactant. Viscosity data over a wide range of temperatures and shear rates are given in Table III. For comparison, an aqueous solution containing 48% of the same 6.5-EO alcohol ethoxysulfate was a non-flowing gel exhibiting a viscosity greater than 40 Pa.s at 50°C.

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• Detergent Compositions (AREA)
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• 1990
  • 1990-08-28 KR KR1019900013308A patent/KR910004791A/ko not_active Withdrawn
  • 1990-08-29 JP JP2225472A patent/JPH0393900A/ja active Pending
  • 1990-08-29 PT PT95140A patent/PT95140A/pt not_active Application Discontinuation
  • 1990-08-30 EP EP19900202317 patent/EP0431653A3/en not_active Withdrawn

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