US 3919125 A
A higher secondary alcohol ethoxysulfate, an aqueous solution of a caustic alkali and ethanol are fed continuously or batch-wise into a neutralization vessel to neutralize the higher secondary alcohol ethoxysulfate so that the three components ethanol (X), water (Y) and the resulting neutralized higher secondary alcohol ethoxysulfate (Z) fall within the range surrounded with the lines connecting the following six points with each other on a triangular coordinate plot, whereby a highly concentrated solution of the neutralized higher secondary alcohol ethoxysulfate is obtained: }(A) X = 10%, Y = 25%, Z = 65% }(B) X = 5%, Y = 25%, Z = 70% }(C) X = 3%, Y = 22%, Z = 75% }(D) X = 4%, Y = 18%, Z = 78% }(E) X = 6%, Y = 14%, Z = 80% }(F) X = 10%, Y = 10%, Z = 80%, } the percentages being % by weight. The solution thus prepared is also disclosed in detail.
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Description (OCR text may contain errors)
United States Patent 1191 Ashina et al.
 Appl. No.1 362,985
 Foreign Application Priority Data May 23. 1972 Japan 4760359 252/553; 252/559; 252/DIG. 5; 252/DIG. l3; 252/DIG. 14; 260/458 51] Int. CIR. CllD l/29:C11D 3/43; Cl 1D 17/08 58] Field of Search 252/532. 551. 353. 363.5. 252/171. 173. DIG. 5. DIG. l3. DIG. 14; 260/458 Nov. II, 1975 FOREIGN PATENTS OR APPLICATIONS 1.052.976 12/1966 United Kingdom 260/458 OTHER PUBLICATIONS McCutcheons Detergents & Emulsifiers 1970 Annual. pp. 55. 70. 91. 123. 138. 212. 217. 220 and 237.
Primary Erma/11er-Dennis E. Talbert. Jr.
Assistant E.\'am1'11erDennis L. Albrecht Attorney, Agent. or F1'1'n1Sughrue. Rothwell. Mion. Zinn & Macpeak  ABSTRACT A higher secondary alcohol ethoxysulfate. an aqueous solution ofa caustic alkali and ethanol are fed continuously or batch-wise into a neutralization vessel to neutralize the higher secondary alcohol ethoxysulfate so that the three components ethanol (X). water (Y) and the resulting neutralized higher secondary alcohol ethoxysulfate (Z) fall within the range surrounded with the lines connecting the following six points with each other on a triangular coordinate plot. whereby a highly concentrated solution of the neutralized higher secondary alcohol ethoxysulfate is obtained:
 References Cited (at) =111'1. a 2 @501 1 1 =11. =1. 1. :111 UNITED STATES PATENTS (c) x 3% Y 22a. 2 2 15; 1. =10 2.694.831 111953 Kosmin 260/458 15; i ii i I} 2.766.212 111/1956 252/551 (F1 X 111 1. 1 1119;. Z 1W2. 2.870.220 1/1959 260/615 3.054.820 9/1962 260/458 3.376.333 4/1968 260/458 3.468.805 9/1969 252/551 X the percentages being 7: by weight. The solution thus 3-5131)9g 5/1970 253/55l X prepared is also disclosed in detail. 3.565.939 2/1971 260/458 x 3.786.003 1/1974 Hunter 252/551 7 Clam! I Drawing Flgul'e ETHNKIL X 1100 II I 1 1100 '1 7,] 11161181 SEIZMJARY ALCOHOL ETHOXY- SULFATE U.S. Patent Nov. 11, 1975 3,919,125
X W /o) AVA AVAYA YYY Y (100 111%) 2110011 WATER HIGHER N Y ALCOHOL OXY- SULFATE METHOD OF PREPARING A HIGHLY CONCENTRATED SOLUTION OF A HIGHER SECONDARY ALCOHOL ETHOXYSULFATE AND SUCH A CONCENTRATED SOLUTION BACKGROUND OF THE INVENTION l. FIELD OF THE INVENTION The present invention relates to a highly concentrated solution of a higher secondary alcohol ethoxysulfate and to a method of preparing the same, more precisely, to a salt of a higher secondary alcohol ethoxysulfate in an aqueous solution of high concentration and fluidity prepared by neutralizing a higher secondary alcohol ethoxysulfate with an aqueous solution of a caustic alkali in the presence of ethanol.
2. DESCRIPTION OF THE PRIOR ART Higher alcohol ethoxysulfate type detergents are widely used for industrial use as well as domestic use, and in particular, have been widely used as liquid kitchen detergents and as shampoos and the like because of their high solubility. high biodegradability and mild skin irritating effect.
Among the higher alcohol ethoxysulfate detergents, it has been found that secondary alcohol type detergents are superior to other alcohol type detergents in the points of permeation, lowered skin irritation and mildness.
in addition, it has become possible to industrially manufacture secondary alcohol type detergents of high quality and stability due to improvements on techniques of sulfating secondary alcohols.
Under these Circumstances, the secondary alcohol type detergents (that is higher secondary alcohol ethoxysulfate type detergents) have recently been in great demand, and the demand is increasing more and more.
The composition of the active ingredient in such detergents usually utilized is, in general, -20%, and the concentration of the active ingredient in the crude solutions of the ethoxysulfates during the manufacture thereof is about -30% or so. in the manufacture of the solutions of these ethoxysulfates, it is economical to make the concentration of the solution as high as possible. Accordingly, the makers of higher alcohol ethoxysulfates have desired an improved method of increasing the concentration of the ethoxysulfates as high as possible during the manufacture thereof.
Under such circumstances, it is considered that if the amount of the detergent could be increased per unit amount of the water used, various advantages would result, e.g., the capacity of the manufacturing apparatus as well as that of storage tanks could be reduced and the expenses for transporting and packaging the products could also be reduced. The latter is particularly important since in this field of manufacturing detergents the product solutions are, in many cases,'transported great distances in the form of undiluted crude solutions to further process and finish the crude solutions. The transported crude solutions are diluted by the final processor to make final products of desired concentrations, depending upon the use thereof.
In general, if the concentration of the higher alcohol ethoxysulfate increases, the viscosity thereof increases with an increase in concentration, and, in particular, if the concentration exceeds or more,'the ethoxysulfates form viscous pastes or non-fluid gels. These pastes or gels cannot be transported by a pump, and thus it be- 2 comes extremely difficult to deal with the resulting ethoxysulfates. Accordingly, the upper concentration limit of the ethoxysulfates is, in general, 30% when they are in the form of an aqueous solution.
However, it has hitherto been known to increase the concentration of such aqueous solutions by adding thereto an organic solvent as a viscosity reducing agent. such as ethanol, propanol, ethylene glycol or the like. The amount of the viscosity reducing agent to be added must be higher with increased concentrations of the resulting solution.
SUMMARY OF THE INVENTION Observing the behavior of higher secondary alcohol ethoxysulfates, which are the subject substances of the present invention, and higher primary alcohol ethoxysulfates whose carbon atoms and added ethylene oxides correspond to those of the former, upon adding a vis cosity reducing agent (for example. ethanol) thereto. the inventors observed that the viscosity of these ethoxysulfates was extremely high when the concentration thereof was 55-60% and a viscosity reducing agent was not present, and that it was necessary to add ethnnol '(as a viscosity reducing agent) to the ethoxylates in an amount of 12-15%, based on the solution of the ethoxysulfates, in order to impart a sufficient fluidity to the solution such that it could be transported by a pump.
However, the use of the ethanol in such high amounts is economically disadvantageous in view of the fact that ethanol is expensive. Moreover, it is difflcult to handle the resulting solution due to a lowering of the M point and an increase of the vapor pressure thereof with an increased content of ethanol. a further disadvantage.
Furthermore, if the content of the ethanol is too high. the final product is not suitable for many end uses. For these reasons. the use oftoo much organic solvent is disadvantageous.
The inventors conducted extensive investigations on the fluidity of a three-com ent system compril'ng an active ingredient (higher secondary alcohol ethoxysulfate), ethanol and water, in order to elimhate the above drawbacks in the preparation of a highly concentrated solution of a higher secondary alcohol ethoxysulfate, and discovered an unexpected characteristic of the three-component system. thus attaining the present invention.
The object of the present invention is to provide an improved method of preparing a highly concentrated solution of a neutralized higher secondary alcohol ethoxysulfate or such an ethoxysulfate mixture. dual:- terized in that a higher secondary alcohol ethoxysolfate, an aqueous solution of a caustic alkali and edsanol are fed continuously or batch-wke into a neutralization vessel to neutralize the higher secondary alcohol ethoxysulfate so that the three components ethanol (X), water (Y) and the resulting neutralized higher secondary alcohol ethoxysulfate (Z) fall within the range surrounded by lines connecting the followim six points with each other on a triangular coordinate plot:
-continued the percentages being by weight of the three components.
The present invention also relates to a detergent composition comprising a mixture of ethanol, water and one or more higher secondary alcohol ethoxysulfate salts, the three components ethanol (X), water (Y) and the higher secondary alcohol ethoxysulfate salts (Z), falling within the range surrounded by the lines connecting the following six points with each other on a triangular coordinate plot:
the percentages being by weight of the three components.
Preferred compositions in accordance with the invention have a viscosity such that pump transport is possible, usually a maximum of about 2,000 cp.
BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a triangular coordinate plot showing the range of the components constituting the products prepared according to the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION The range of the components constituting the products of the present invention is shown in the attached drawing. With reference to the drawing, the solutions of compositions falling in the upper portion of the range surrounded with the lines connecting the points A, B, C, D, E and F in this order have a viscosity of 2000 centipoises or less at 25C, and these solutions are so fluid that they can easily be handled and transported by a pump.
When the concentration of the active ingredient of the solution is 60%, it is necessary to add 13% of ethanol to the solution, e.g., a solution of a higher primary alcohol ethoxysulfate as described above, in order to impart thereto fluidity sufficient for transporting by means of a pump. However, the amount of ethanol added to impart the desired fluidity to the solution decreases, rather contrary to expectations, with a further increase in the concentration of the active ingredient in the solution, and when the concentration of the active ingredient is 75%, the object of the present invention of imparting a sufiicient fluidity to the solution is fully attained with a smaller amount of added ethanol, or only 3% thereof. This is quite an unexpected efi'ect.
The present invention thus is based upon the discovery of a specific characteristic of the higher secondary alcohol ethoxysulfates (such as a sodium salt) which has hitherto been unknown.
The higher secondary alcohol ethoxysulfates are obtained by adding I to 8 mols of ethylene oxide to 1 mol of a higher secondary alcohol containing 10 to l6 carbon atoms and sulfating the adduct.
The higher secondary alcohols of 10 to 16 carbon atoms are generally produced by oxidizing C m to C n-paraffins.
They can be represented as:
where n+m+3 10 to 16, where n and m are integers. They are commercially available, typically in mixture form, e.g., TergitoF' by Union Carbide Corporation, SoftanoP by Japan Catalytic Chemical Industry Co., Ltd. Unitol by Nitto Chemical Ind. Co., Ltd., etc.
The higher secondary alcohol ethoxysulfates can be prepared according to known procedures, e.g., U.S. Pat. No. 2,870,220 Carter.
Generally, higher secondary alcohols are poor in reactivity compared with the higher primary alcohols. A useful reaction product can be obtained at very mild reaction conditions, e.g., at normal pressure by reaction with chlorosulfonic acid at low temperatures, by contact with an SO -containing gas at low temperatures using a conventional thin-film reactor, etc.
For example, when a solution of a higher secondary alcohol ethoxylate is stirred while keeping the temperature at 5C, 1.2 chemical equivalents of chlorosulfonic acid are dropped into the solution while keeping the temperature at 5C over about 2 hours, and, after reacting, hydrochloric acid is driven off by blowing air into the system and then the resulting solution is neutralized by adding an NaOH aqueous solution at not more than 50C, a useful reaction product thus is obtained. The reaction proceeds smoothly at normal pressure.
In the method of the present invention, a higher secondary alcohol ethoxylate, an aqueous solution of a caustic alkali (such as a caustic soda aqueous solution) and ethanol are treated for neutralization by a continuous operation or a batch operation so that the composition of the final product falls within the range surrounded by the lines connecting the six points A, B, C, D, E and F as shown in the drawing. In the lower region of the range, however, the viscosity of the solution exceeds 2000 centipoises at normal temperature (25C),. and thus it is difficult to handle such a solution. On the other hand, in the upper region (above the line A-E), although sufficient fluidity can be attained in the resulting solution so it can be easily transported by a pump, the concentration of the ethanol therein exceeds 10%, and thus the solution in this upper region (containing a large amount of expensive ethanol) is economically disadvantageous. In addition, the use of such a large amount of ethanol causes a lowering of the flash point of the resulting solution and increases the vaporization rate thereof, and thus, it becomes difficult to handle the resulting solution.
The temperature of the neutralization procedure of the present invention is not specifically limited, and the temperature can be any common neutralization temperature for higher alcohols ethoxysulfates, for example, about 0to about C or so.
The pressure of the neutralization procedure is also not specifically limited in any manner, and both suband super-atmospheric pressures can be used. However, as one skilled in the art will appreciate, such is not necessary for a neutralization procedure, and, generally speaking, little is to be gained by operation at other than atmospheric pressure, and for all practical commercial purposes such will be the case.
The time of operation is not overly critical so long as complete reaction is achieved, and, since the reaction is exothermic, so long as the ethoxysulfate material is not degraded. Generally speaking, the neutralization will be performed in a period of from about minutes to about 2 hours. If one wishes to use a longer time, a lower temperature will generally be used, while, on the other hand, if one wishes a shorter time, a higher temperature will generally be used, keeping in mind that under all circumstances ethoxysulfate material decomposition should be avoided.
As will be apparent to one skilled in the art, the alkali material should be present in an amount at least stoichiometric to the ethoxysulfate for the neutralization. As a general rule, considering the low cost of alkali materials and the desire to achieve as complete neutralization of the ethoxysulfate as is possible, usually a 10% excess of alkali over the stoichiometric amount will be used. This provides a safety factor for the reaction.
During the neutralization procedure, it is important to maintain the pH of the system at a pH of 8 I about 0.5, i.e., at a pH of about 7.5 to about 8.5. This is important because acidic conditions should be avoided which decompose the ethoxysulfate. On the other hand, if the system becomes too basic a tendency of the ethoxysulfate to degrade is encountered. Balancing both of these factors, reaction proceeds in a smooth, excellent manner at a pH of 8 t 0.5.
According to the method of the present invention, the amount of the ethanol added can be small and the concentration of the active ingredient in the solution can be made high, even with the use of only a small amount of ethanol. Therefore, the present method is economically and practically very advantageous.
The strength of the alkali material used is, of course, not overly important. Weak or strong alkali materials can be successfully used, and the concentration of the alkali basically only effects the rate of addition, i.e., the concentration does not effect the amount of alkali required. Practically speaking, one will use sodium hydroxide because of its low cost, ready availability and suitability for the neutralization. However, the present invention is by no means limited thereto, and one skilled in the art can select other alkali materials considering the economics of the reaction and the use of the concentrated product. While it is most preferred to use an aqueous sodium hydroxide solution, most preferably at a sodium hydroxide concentration of to 50% by weight of the aqueous solution, other alkali metals such as potassium hydroxide, lower trialkanol amines, for instance, C C alkanol amines, ammonia, and the like, can also be used. In this regard, the method of the present invention is most profitably practiced with an undiluted caustic alkali solution as is typically available as an industrial raw material, and generally comprises about 45 to 48% caustic soda in an aqueous solution, based on aqueous solution weight.
Furthermore, while in the present invention the discussion is in terms of adding alkali in the form of an aqueous solution, it is theoretically possible to use a solid alkali material or, in fact, to bubble a gaseous material into the neutralization bath. However, on an industrial scale, the process control for such embodiments is difficult as compared to the simple process possible with an aqueous alkali solution, so that in practice an aqueous alkali solution will generally be used. Further problems encountered with the use of solid or 6 gaseous alkalis will be a tendency to partial reaction, leading to an inferior product.
The procedure of addition of the components is not especially limited. For instance, one can use a continuous feed of the ethoxysulfate, ethanol and an aqueous alkali solution (generally the water in the aqueous alkali solution being the water in the end product). Of course, in addition to such a continuous feed the ethanol can be first added and then the remaining components added. Alternatively, the aqueous alkali solution can be first added in a batch reaction and the ethoxysulfate and ethanol added thereto. However, with this latter procedure a tendency to partial reaction and difficulty of process control is encountered, and this nonpreferred. Other modifications and additions to the procedures set above will be apparent to one skilled in the art.
Although the above discussion has been primarily in terms of the production of a concentrated solution in accordance with the present invention where only ethoxysulfate, water (aqueous solution of sodium hydroxide) and ethanol are added for the neutralization, other component can be present in the system so long as they do not interfere with the neutralization/concentrating procedure. For instance, commercially available ethoxysulfates often contain a small amount of unreacted ethoxylate. The reason for this is that complete sulfation is difficult on a commercial scale, and most users find it perfectly acceptable for a small amount of ethoxylate to be present. For example, on the order of 5-l0% of ethoxylate (based on the weight of neutralized ethoxysulfate) has no significant detrimental affect on the present invention, and such can be present in the concentrated solution obtained in accordance with the present invention.
It will further be apparent to one skilled in the art that after forming the concentrated solution of the present invention, other materials can be blended therewith to yield an end use detergent composition, if desired, though, of course, the composition can be used as it is as a detergent composition.
Such additive materials can, if desired, be incorpo rated in the detergent composition, for example, in an amount of up to about 50% by weight of detergent composition, in order to achieve the above effects. A specific example of one such formulation would be,
Ethoxysulfatc 35 parts by weight Alkylbenzcncsulfonatc 35 Alcohol Ethoxylate l0 Alkylolamidc 20 in an appropriate volume of water.
Typical of such alcohol ethoxylates are;
C,,H,,,.,0-(CH,,CH,0 ,,H where n is 10 to 16, and m is 7 to 20, and typical of such alkylolamides is;
C,,H CON(CH CH OH (Di-ethanolarnide l.
7 The concentrated detergent solution of the present invention can, of course, be blended with an alkylbenzene sulfonate, if desired.
The present invention will now be explained in more detail in the following examples, which were conducted at atmospheric pressure.
EXAMPLE 1 Higher secondary alcohol ethoxylates (Tergitol 45- 3-8", product of the Union Carbide Corporation, having an average molecular weight of 356), which were obtained by adding 3 mols of ethylene oxide to higher secondary alcohols of 14 and 15 carbon atoms which 8 EXAMPLES 2 l0 AND REFERENCE EXAMPLES l 8 in a neutralization vessel provided with a stirrer there was fed ethanol in such an amount that the concentration thereof in the final product was at a predetermined value, and then, a caustic soda aqueous solution (source of water) and secondary alcohol ethoxysulfates (prepared by the addition of an average of three mols of ethylene oxide to one mole of a secondary alcohol mixture of 14 carbon atoms, followed by the sulfation of the resulting adduct with sulfur trioxide, available as Unitol 45-8-38 produced by Nitto Chemical 1nd. Co., Ltd.) were added to the ethanol in such amounts that the concentration of the active ingredient l5 were liquid phase oxidation products of n-paraffins 1n the final product reached a predetermined value were continuously poured on the inside wall of a thin under a pH value of 8 i 0.5. The temperature was C film-type tubular reactor and contacted with 80,, gas at the beginning of the neutralization and 70C at the diluted with a dried air, and then the resulting gas sepacompletion of the neutralization. The neutralization rated to obtain the corresponding higher secondary al- 20 took 1-2 hours. coho] ethoxysulfates as the reaction product. The composition and the fluidity of the resulting final The reaction was conducted at nonnal pressure at product are shown in the following Table. The viscosity 50C using a reactor jacket, and the molar ratio of the was measured by a Brookfield viscometer.
Table Point Amount of Amount of Amount of Viscosity Example No. in the Active Water (7: Ethanol (C) Drawing ingredient by weight) (1 by weight) (centipoisc) (l by weight) Range of 2 A 65 25 10 2,000 Present lnvention 3 B 70 25 5 4 c 75 22 3 s o 78 I8 4 6 E so l4 s 7 F 80 10 l0 a o 75 20 s 600 9 H 75 l8 7 as 10 1 7o 23 7 :50
Reference 1 .l 69 3 l O gelatin 2 K 60 31 9 3 L 60 10 25.000 4 M 60 27.5 12.5 2.000 s N so 37 l3 6 O 40 60 O gelation 7 P 40 51 9 2.000 8 0 2a 72 o SO gas to the ethoxylates fed was 1.05. 496 weight parts of the reaction product, [03 weight parts of an Active anion ingredients (higher secondary alcohol 70.3 ethoxysulfu tci l Glaubcr's salt 0.5 wt it Ethanol 7.0 wt 1 Water 14.0 wt *1 Others (e.g., unrcuctcd ethoxylatcl 3.4 wt 1' The viscosity of the resulting solution at the outlet was 200 c.p. at 25C. [The above anlysis was conducted using the Epton Method (Methylene Blue Test)].
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
What is claimed is:
l. A method of preparing a concentrated solution of one or more sodium salts of higher secondary alcohol ethoxysulfate having a viscosity of 2000 centipoises or less at 25C characterized in that a higher secondary alcohol ethoxysulfate obtained by adding 1 to 8 mols of ethylene oxide to l mol of higher secondary linear alcohol and sulfating the obtained adduct, which higher secondary linear alcohol has a general formula in which n-l-m+3=l0 to 16, where n and m are integers, an aqueous solution of a caustic soda and ethanol are fed into a neutralization vessel to neutralize the higher secondary alcohol ethoxysulfate, the neutralization being conducted at a pH of 8: about 0.5, so that the three components of ethanol (X), water (Y) and the 3,919,] 25 9 10 resulting one or more sodium salts of higher secondary higher secondary linear alcohol and sulfating the obalcohol ethoxysulfate (Z) fall within the range surmin d add t, whi h high r secondary linear alcohol rounded by the lines connecting the following six points has a general formula with each other on a triangular coordinate plot:
(C) x=m Y=226t 2-15 (m x=4q Y=|sq z==1|m (E) x=w v-lm z-soq (Fl X Y Z in which rrl-nrl-3=l0 to [6, where n and m are integers. said three components of ethanol (X). water (Y) and the percentages b i b i h the sodium salts) higher secondary alcohol ethoxy- 2. The method of claim 1 where the method is contin- Sulfate (Z) falllng within the ranges surro ed by lh mm lines connecting the following six points with each 3. The method of claim I where the method is batchother on a \riansular coordinate pl wise.
4. The method of claim I conducted at about 0C to m x me. v 25%. z as:
about 100C. (BI x-s'l. v-zsq. z-voq a o I 2 5. The method of claim I conducted In about l0 mm- ,1, 3:;
utes to about 2 hours. (El x-s Y- mi; 2-80 6. The method of claim 5 conducted in about I to 2 x Y z hours.
7. A detergent composition comprising ethanol. the percentages being by weight of the three compowater and one or more sodium salt( s) of higher secondnents, said detergent composition having a viscosity of ary alcohol ethoxysulfate. said ethoxysulfate obtained 2000 centipoises or less at 25C. by adding I to 8 mols of ethylene oxide to 1 mol of g g t UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,919,125 DATED 1 November 11, 1975 INVENTOR( I Yoshiro Ashina. etaal H is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 7, line 54, after "solution" delete "compliting" and insert therefor upon completing after "reaction" delete "system".
Signed and Scaled this fourth Day of May 1976 [SEAL] A ttesr:
RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmr'ssimu'r l fpdlrf'lfj and Trademarks