US 3909460 A
This invention concerns water soluble surfactants prepared by introducing solubilizing groups such as sulfates and polyoxyalkylenes into the dioxolane condensates of alkyl ketones with glycerol. These surfactants are particularly useful in detergent compositions.
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United States Patent [191 McCoy 51 Sept. 30, 1975 DETERGENT COMPOSITIONS CONTAINING DIOXOLANES AS SURFACTANTS AND THEIR PREPARATION  Inventor: David Ross McCoy, Wappingers Falls, NY.
 Assignee: Texaco Inc., New York, NY.
 Filed: Aug. 10, 1973  Appl. No.: 387,426
Related US. Application Data  Continuation-impart of Scr. No, 847,729, Aug. 5.
OTHER PUBLICATIONS Chemical Abstracts, Vol. 50, Dispersing agents for solids in liquids, 10947i.
Chemical Abstracts, Vol. 38, 2-Methyl-2'nonyl-4- hydroxymethyl-l ,3-dioxolane and carbamates thereof," 6841c.
Primary ExaminerBenjamin R. Padgett Assistant Examiner-E. Suzanne Parr Attorney, Agent, or FirmT. H. Whaley; C. G. Ries; Bernard Marlowe  ABSTRACT This invention concerns water soluble surfactants prepared by introducing solubilizing groups such as sulfates and polyoxyalkylenes into the dioxolane condensates of alkyl ketones with glycerol. These surfactants are particularly useful in detergent compositions.
14 Claims, No Drawings DETERGENT COMPOSITIONS CONTAINING DIOXOLANES AS SURFACTANTS AND THEIR PREPARATION This invention is a continuation-in-part of Ser. No. 847,729, filed in the United States Patent Office on Aug. 5, 1969 now pending.
BACKGROUND OF THE INVENTION This invention concerns water solubilized ketals, their preparation and their utilization.
More particularly this invention relates to the solubilized condensates of glycerol with dialkyl ketones. These products are useful as surfactants, as components of detergent compositions and as organic intermediates, particularly pharmaceutical intermediates.
While all of the above condensates have utility as surfactants and/or intermediates for organic transformations, as in any large class of compounds, there are frequently considerations which cause one or more substances falling within the scope of the broad class to be favored over the others. In this instance, dioxolane condensates of glycerol with dialkyl ketones containing 6 to 30 carbon atoms, wherein the solubilizing groups are selected from the group consisting of phosphate, ethoxylate and sulfate are favored because they are formed from relatively inexpensive reactants and exhibit substantially better surfactant properties than do the members of the broad class of condensates of a whole.
Within the above-designated group of dioxolane derivatives are the preferred dioxolane derivatives of this invention. These compounds are solubilized derivatives of 2,2-di-n-alkyl l ,3-dioxolane-4-methylols having the formulae:
of which R and R are the di-n-alkyl residuum of the din-alkyl ketones of the formula wherein R and R, which can be the same or different n-alkyl groups, contain a total of 6 to 30 carbon atoms and X represents the solubilizing group preferably ethoxylate, sulfate or phosphate.
The terms surfactant or surface-active, which are used throughout this disclosure, are synonymous and refer to substances which, in solution, are used by themselves or in conjunction with cleaning adjuvants such as additives or builders to form cleaning compositions. Resultantaqueous solutions of surfactants are widely used to wet surfaces, remove soil, penetrate porous materials, disperse particles, emulsify oils and greases, etc., dependent upon the particular characteristic of the surfactant or surfactants used.
Desirably surfactants are stable, inexpensive, light colored materials which function at low concentration levels in solution and which can be produced from readily available starting materials, free from deleterious contaminants, preferably as easily handled, freeflowing liquids or powders.
Recently the applicants have found that the above described dioxolane derivatives not only satisfy all of these requirements but are produced in good yield in a form that easily and rapidly dissolves in aqueous solutions.
SUMMARY OF THE INVENTION In its broadest contemplated process embodiment the surfactants of this invention are prepared by introducing at least one solubiling group into the dioxolane reaction product formed by reacting glycerol with di-nalkyl ketones containing at least 6 carbon atoms in the molecule.
In its favored process embodiment at least one solubilizing group selected from the group consisting of phosphate, sulfate and polyethoxylate is introduced into a dioxolane prepared by condensing glycerol with dialkyl ketones containing between 6 to 30 carbon atoms, until a water soluble surfactant is formed.
In its preferred process embodiment, a dioxolane prepared by condensing glycerol with a mixture of di-nalkyl ketones containing from about 10 to 15 carbon atoms is further treated with a source of solubilizing groups selected from the group consisting of chlorosulfonic acid, phosphoric acid, ethylene and propylene oxide, to produce a water-soluble surfactant.
In its most preferred process embodiment, a mixture of 2,Z-di-n-alkyl-4-hydroxymethyl-1,3-dioxolanes, derived from the acid-catalyzed condensation product of glycerol with a mixture of di-n-alkyl ketones (said ketones being preferably derived from the dehydrogenation of secondary alcohols prepared by the boric acidcatalyzed air oxidation of linear hydrocarbons containing about 10 to 15 carbon atoms) is sulfated with a dialkyl etherchlorosulfonic acid complex, until] a sulfate grouping is introduced into said dioxolane, then treated with a basic substance such as ammonia gas, ammonium hydroxide and alkali metal basic salts until a water soluble surfactant is produced.
To further aid in the understanding of the inventive concept the following additional disclosure is submitted:
A. Dialkyl Ketones The dialkyl ketones which are coreactants with glycerol to form the parent dioxo lanes can be simple ketones or mixed ketones, containing from 6 to 30 carbon atoms. These ketones can be in the form of single highly purified compounds or in the form of mixtures of different ketones. The favored ketones are those containing from 10 to 15 carbon atoms, that is, wherein the carbon content of the dialkyl substituents total 9 to 14 carbon atoms, or wherein the carbon content of the dialkyl substituents total 10 to 12 carbon atoms especially in the form of certain ketone mixtures derived from the dehydrogenation of secondary alcohols obtained from the boric acid-catalyzed air oxidation of linear hydrocarbons containing from about 10 to 15 carbon atoms. The preferred ketones are the normal ketones resulting from the above oxidation process. Illustrative ketones which can be used include di-npropyl ketone, methyl butyl ketone, methyl pentyl ketone, dibutyl ketone, methyl nonyl ketone, dihexyl ketone, dioctyl ketone, dinonyl ketone, dodecyl ketone, didodecyl ketone and the like.
B. Solubilizing Groups In order to obtain good surfactant properties in the dioxolanes of this invention it is necessary to place at least one solubilizing group in the molecule. Solubilizing groups as used throughout this disclosure refer to groups which increase the solubility of the dioxolane in water to suchan extent that the dioxolane exhibits surfactant properties. Illustrative solubilizing groups include sulfates (OSO OH), chlorides, bromides, nitrates, phosphates, alkoxylates such as ethoxylate or propoxylate, and the water-soluble ammonium salts or alkali metal salts, where the solubilizing group permits their formation.
In most instances these solubilizing groups can be introduced into the dioxolane molecule by well known previously described techniques. For example, chlorides or bromides can be prepared using the appropriate phosphorus oxyhalides/Similarly the dioxolane can be'alkoxylated between 50 and 175 to' the extent where l to or more groupings, preferably 4 to 14 groupings, are placed in the molecule using alkylene oxides such as ethylene, propylene or butylene oxides using strongly alkaline catalysts such as the alkali met als, i.e., sodium as well as their strongly alkali metal salts such as sodium and potassium hydroxides and a1- koxides.
As indicated above, most of the water solubilizing groups can be introduced into the dioxolane molecule using standard preparative techniques. However, in the case of the sulfate group (OSO OH), quite unexpectedly prior art sulfation techniques either decomposed the dioxolane to the ketone or no reaction took place at all. For instance, oleum, sulfamic acid and chlorosulfonic acid alone and sulfur trioxide-pyridine complexes were unsuccessful in introducing the sulfate group into the molecule under a variety of reaction conditions. The only wholly satisfactory sulfating agent was found to be a complex of chlorosulfonic acid with dialkyl ethers such as diethyl ether. These complexes are formed by admixing the two components in molar ratios ranging from 0.5 to 4.0 moles of the ether for each mole of acid. The sulfation of the dioxolane is carried out at atmospheric or near atmospheric pressures between to +35C preferably between 10 to +25C. The molar ratio of sulfating complex to dioxolane varies between at least equimolar amounts, preferably to a slight excess 1.1-1.5:1) of sulfating complex to dioxolane.
To prepare the ammonium salt of the sulfated dioxolanes, the dioxolane is treated with at least a stoichiometric quantity of gaseous ammonia either neat or in the presence of inert solvent such as benzene or diethyl ether at temperatures ranging from 25C to +C.
The sodium and potassium salts are prepared in the usual fashion by contacting the sulfated dioxolane with aqueous solutions of the alkali metal hydroxide, carbonate or alkoxide.
C. Utilization of the Solubilized Dioxolanes as Surfactants.
1. Concentration. The sulfate, phosphate or alkoxylate containing dioxolane derivatives exhibit surfactant properties in aqueous solution in concentrations ranging from 0.01 weight percent and upwards. The upper limit is determined primarily by cost and for all but special purposes seldom exceeds 20% by weight. In all instances this lower concentration is referred to as a surfactant amount or effective quantity of surfactant.
D. Utilization of the Solubilized Dioxolanes as Detergents When the dioxolane derivatives are employed as detergents they ordinarily are present in at least the minimal concentrations disclosed supra accompanied by one or more of the following classes of materials which are generically referred to as detergent adjuvants:
1. Inorganic salts, acids and bases. These are usually referred to as builders. These salts usually comprise alkalies, phosphates and silicates of the alkali metals as well as their neutral soluble salts. These materials constitute from about 40 to weight percent of the composition in which they are employed.
2. Organic builders or additives These are substances which contribute to characteristics such as detergency, foaming power, emulsifying power or semisuspending effect. Typical organic builders include sodium carboxymethyl cellulose, citrates and sequestering agents such as ethylenediaminetetraacetic acid and the fatty monoethanolamides, etc.
3. Special purpose additives These include solubilizing additives such as lower alcohols, glycols and glycol ethers, bleaches or brighteners or various structures which share in common that they are dyestuffs and they do not absorb or reflect light in the visible range of the spectrum.
E. Testing and Evaluation Procedures In order to accurately gauge the value of the solubilized dioxolanes as wetting, detergent and surfactant agents, carefully standardized procedures must be used. These are shown below:
1. Standard Launder-Ometer Test.
Ten standard wash solutions ranging in detergent content from 0.5 to 0.30 weight percent (they are 0.015, 0.10, 0.10, 0.010, 0.20, 0.30, 0.30) and ten standard wash solutions ranging in sodium sulfate content from 0.075 to 0.70 weight percent (they are 0.75, 0.067, 0.15, 0.133, 0.30, 0.466, 0.20, 0.45, 0.70) are prepared in 3,000 ppm hard water. The hard water was previously prepared by dissolving 26.43 grams of CaCl .2I-I O in 600 ml of distilled water and mixing this solution with a solution of 29.58 grams of MgSO .7H O in 600 ml of distilled water and making up the admixed solutions up to 10 liters with distilled water.
Standard soiled cloths containing the same amount of soil are placed in each solution and Washed in a Launder-Ometer* for 10 minutes at 60C. The cloths are removed from the wash solutions, rinsed, dried and the degree of whiteness measured by a Photovolt Reflectometer**. The data obtained are plotted and expressed as Average Detergency Coefficient. This term is derived by expressing the soil removal properties of the experimental detergent as a percentage of a known standard detergent at 0.25 weight percent concentration **Photovolt Reflectomcter The apparatus used is the Photovolt Reflection Meter 670, Search Unit 610-W sold by Photovolt Corporation, New York, N.Y.
2. Standard Foam Test This is the procedure described in ASTM procedure No. D1 173-53.
Preparation of 2,2-Di-n-alkyl-4-Hydroxymethyl-1,3-Dioxolane.
To a reaction vessel equipped with heating, cooling and stirring means and means of stripping of a water azeotrope, is added 137 parts by weight of=glycero1, 5 parts by weight of p-toluenesulfonic acid, 500 parts by weight of benzene and 260 parts by weight of a mixture of (Z -C di-n-alkyl ketones derived from n paraffins and having an averagemolecular weight of 185. The reaction mixture is stirred and refluxed for 65 hours while taking off the waterbenzene azetrope.
When water formation ceases'the catalyst is removed by water washing and the solvent is distilled off. A product which LR. and molecular weight analysis confirms to be the desired 2,Z-di-n-alkyl-4-hydroxymethyl- 1,3-dioxolane is removed by vacuum distillation from unreacted ketone and higher molecular weight byproducts. The'dioxolane mixture had an average molecular weight of about 260.
Embodiment B: A mixture of (I -C alkyl ketones, obtained by,the catalytic dehydrogenation of C -C secondary alcohols from the boric acid-directed oxida-.
tion of C, C, n-paraffins and having an average molecular weight of 185, was treated in a manner identical to that in Embodiment A toobtain the corresponding 2,2di-n-alkyl-hydroxymethyl-1,3-dio.xolane. i
v Embodimen tCz Preparation of Specific Dioxolane Using the preparative procedure described by Berger, F.M., in Arch Intern Pharmacodyn, the following known 2,2-di-nalkyl-4hydroxymethyl (or methylol)'- 1,3-dioxolane is prepared by condensing the indicated ketone with glycerol.
Infra-red and molecular weight analysis confirms that the desired dioxolane is prepared.
Preparation of the Ethoxylate of 2.2-Di-n-alkyl-4-Hydroxymethyl-1,3-Dioxolane To an appropriate reaction flask equipped with a means of stirring, heating, cooling and passing gas into the flask, is added 50 parts by weight of 2,2-di-n-alkyl- 4-hydroxymethyl-l ,3, dioxolane (having an average molecular weight of 260 whose preparation is described in Embodiment A) and 2 parts by weight of potassium hydroxide. Ethylene oxide is introduced into the flask at atmospheric pressure ata flow rate of 0.25 g. per minute while maintaining the temperature between 100 and 130C. After 3 hours, one mole of ethylene oxide is added which amounts to about 5.3 moles of ethylene oxide/mole of the dioxolane. The addition of ethylene oxide is discontinuedat'this time, the solution is cooled to room temperature and 2.5 parts of concentrated (specific gravity 1.19) hydrochloric acid V *EXAMPLE 2. Preparation of a More Highly Ethoxylated Dioxolane.
Using the same reaction set-up, dioxolane and tech- 0 nique as describedin Example 1, a 50 parts by Weight portion of the dioxolane containing 1 part by weight :of sodium metal catalyst is treated with 9.2 moles of ethylene oxide/mole of dioxolane over a 4 hour period at a reaction temperature between 125C. After acidification, cooling and filtration the product analyzed by molecular weight of hydroxyl number is found to be a 9.1 molar ethoxylate of 2,2-di-n-alkyl-4- hydroxymet hyl- 1 ,3-dioxolane'. This compound is alight yellow, free-flowing liquid that dissolves immediately cold water. i g 2 *In this example and in all instances wherein the moles of ethoxylate in the molecule are disclosed, it is to be understood that these numbers represent an average number of moles of ethyleneoxide placed in the molecule.
EXAMPLE 3. lna manner similar to that in Example 2 a 8.5 molar ethoxylateof the dioxolane of Embodiment A was formed.
In a manner similar to that in Example 2 a 9 .molar ethoxylate of the dioxolane of Embodiment B was formed.
Preparation of Monosulfated 2,2-Di-n-alkyl-4- Methylol-l,3-Dioxo1ane and Ammonium, Sodium and Potassium Salts.
A 50 parts by weight portion of the dioxolane prepared in Embodiment A is admixed at 10C with a 58 parts by weight portion of 1:1 molar complex of chlorosulfonic acid with diethyl ether in an appropriate reaction vessel having provisions for stirring, heating and cooling. After a period of 1 hour, the sulfation reaction is stopped and the product treated at -10C with an excess of NH gas. Inorganic material is removed by filtra tion to obtain a good yield of the ammonium salt of sulfated dioxolane derivative, identified by [.R. and elemental analyses. This product exhibits desirable foaming properties (high but unstable foam, see Table 11) in aqueous solution.
ln a similar manner, sodium (B) and potassium (C) salts of sulfated 2,2-di-nalkyl-4-methylol-1,3- dioxolane are prepared from the sulfation reaction mixture above by adding the latter to an aqueous solution containing an equimolar amount of sodium hydroxide or potassium hydroxide and kept at -25C by external cooling. The desired products B and C are isolated by removal of water and extraction of the residue with an organic solvent. These products demonstrate desirable foaming and detergency properties.
Evaluation of Illustrative Solubilized Dioxolanes as Surfactants and Comparisons of the Solubilized Surfactants with Comparable Commercially Available Products.
Testing Procedures EXAM PLES 7-8.
, Preparation of Ethoxylated 2-n-NonyI-2-Methyl-4-Methylol-l ,3-Dioxolanes.
Using the procedure described in Example 1, 50 parts by weight portions of the specific dioxolane, whose preparation is described in Embodiment C is ethoxylated by passing in an excess of ethylene oxide in the presence of potassium hydroxide, keeping the temperature between IOOI30C under a nitrogen at mosphere. After the desired extent of ethoxylation is achieved, the additionis'discontinued and the catalyst is neutralized with concentrated hydrochloric acid, filtered and analyzed as described in Example 1. Products with an average of 9.5 moles and 15.4 moles of ethylene oxide units are prepared in this manner.
In all instances good detergency coefficients are obtained using the previously described tests.
Preparation of Specific 2,2-Di-n-aIkyI-4-Methylol-l ,3-Dioxolane Sulfates.
Using the sulfation procedure described in Example 5 A, 50 parts by weight portions of the specific dioxo- Iane whose preparation is described in Embodiment C is sulfated using a stoichiometric excess of a chlorosulfonic diethyl ether complex 1:1 molar ratio) to dioxolane. The stirred mixture of sulfating agent, dioxolane and diethyl ether is kept at +IOC for I hour in each instance. At this time the reaction is stopped and the isolation and purification procedure used in Example 5 A is followed. The products identity is confirmed by IR. and elemental analysis. The product is the monosulfate of the 2-n-nonyI-2-methyl-4-methylol-I,3-dioxolane in the 4 position.
The monosulfate exhibited good detergency coefficients using the previously described standard test.
In order to assess the effect of various inorganic and organic builders on the detergency properties of the vsolubilized dioxolanes, compositions containing weight percent detergent (products from Examples l-5 and 7-9) and weight percent builder (including the following: tetrasodium pyrophosphate, sodium tripolyphosphate, sodium carbonate, sodium citrate, ammonium citrate, ammonium phosphate, sodium carboxymethyloxysuccinate, sodium nitrilotriacetate and tetrasodium ethylenediaminetetraacetate) were prepared. The effectiveness of these compositions as detergents compared to 30/70 compositions of commercial surfactants with the same builders was measured in the previously described Launder-Ometer test. These data (some of which are shown in Table III) demonstrate. the complete compatability of the solubilized dioxolanes with the builders listed.
' TABLE I Average Dctergency Coefficients (ADC) Experimental Detergent STANDARD DETERGENT ADC Product from Example I Commercial C,,-C, sec. alcohol 9-molar ethoxylatc 107 Product from Example 2 Commercial C -C prim. alcohol l I-molar ethoxylate I08 Product from Example 5, NH, salt of sulfated commercial C,,-C,,, see.
Part "A" alcohol 3-molar ethoxylate I05 TABLE II ASTM No.Dl 173-53 Foam Test Detergent (at 1% concentration) Foam Height in mm. at
0 5 10 15 min. Product from Example 5,Part A 185 25 20 5 NH, salt of sulfatcd commercial 200 I I65 C,,C,,, sec. alcohol 3-molar ethoxylate TABLE Ill Average Dctergeney Coefficients (ADC) using Different Builders Experimental Detergent- Product from ADC vs. Commercial Cm'C Prim. Alcohol 9-Mular E h xylm n sI-r. .lh'alml n-Mulnr Ethoxylatc) Tetrasodium Sodium Tri- Sodium Sodium Pyrophosphate Polyphosphate Carbonate Citrate Examplel lll(ll3) |l4(ll5) ll9(ll3) l23(ll9) Example 3 95.5 (98.5) 94.6 (95.7) 97.8 (93.2) 99 (95.2) Example 4 93.5 (96.4) 92.5 (93.5) 104 (99.5) 93.5 (90) As the several embodiments and examples indicate, the novel invention is advantageous and gives rise to unexpected results in both its composition and process aspects. For example, the novel solubilized dioxolanes of this invention are superior surfactants in an aqueous environment. This has been demonstrated by their equivalent to slightly superior detergency when compared to the best comparable ethoxylated fatty alcohol commercial detergents. In addition, the solubilized surfactants are inexpensive, free flowing liquids that exhibit effective surfactant properties at relatively low concentrations. The finding that the solubilized ketals of this invention (formed from glycerol and dialkyl ketones containing 6 and higher carbon atoms) have substantially better solubility and color properties than the comparable solubilized acetals was particularly surprisileretofore, based upon the disclosure of British Pat. No. 414,772 it would have been expected that the solubilized acetals (such as the ethoxylated condensation product of lauryl aldehyde and glycerol disclosed in Example l of the above patent) would have comparable properties to the seemingly related ketals. As Example 2 of this application indicates, this is not the case. For example, the solubilized ketals of this invention have substantially superior water solubility compared to the corresponding acetals of the British Patent. In addition, the solubilized ketals of this invention are much lighter than the solubilized acetals. Inasmuch as the solubilized acetals of the British Patent are structurally similar to the solubilized ketals, the substantial differences in color and solubility could scarcely be predicted.
The novel process of sulfating the dioxolanes (ketals) is also quite unexpected in view of the prior art. According to the same British patent one would expect that the sulfated ketals of this invention could be made as disclosed in the British patent simply from chlorosulfonating the ketal. However, surprisingly, the ketals of this invention are decomposed by sulfation with chlorosulfonic acid or sulfur trioxide-pyridine and can only be sulfonated in good yield using dialkyl ether chlorosulfonic acid complexes. Example 5, A of this application establishes this.
In view of the preceding specification it is apparent that numerous changes, modifications and substitutions can be made in choice of polyol or ketone reactant, solubilizing group and reaction conditions. The metes and bounds of this invention are best established by the claims which follow, read in the light of the specification.
What is claimed is:
l. A detergent composition consisting essentially of:
a. from about 0.01 to parts by weight of a watersoluble derivative of 2,2-di-n-alkyl-4-methylol-1,3-
dioxolane wherein the alkyl groups of the dioxolane contain 5 to 29 carbon atoms, said dioxolane having a molecular weight ranging from about 185 to 260, said water-soluble derivative being selected from the group consisting of the monosulfate of 2,- 2-dialkyl-4-methylol-l,3-diioxolane, the ammonium salt of the monosulfate of 2,2-di-n-alkyl-4- methylol-l,3-dioxolane, the ethoxylates of 2,2- dialkyl-4-methylol-l ,3-dioxolane wherein the average number of moles of ethylene oxide contained in said dioxolane ranges from about 5 moles to 16 moles, b. from about 40 to parts by weight of a builder c. a residuum of inert ingredients. 2. The detergent composition of claim 1 wherein the builder is sodium citrate.
3. The detergent composition of claim 1 wherein the builder is sodium carbonate.
4. The detergent composition of claim 1 wherein the builder is tetrasodium pyrophosphate.
5. The detergent composition of claim 1 wherein the builder is sodium tripolyphosphate.
6. The detergent composition of claim 1 wherein the carbon content of the dialkyl substituents total 10 to 12 carbon atoms.
7. The detergent composition of claim 1 wherein the carbon content of the dialkyl substituents total 9 to 14 carbon atoms.
8. The detergent composition of claim 6 wherein the watersoluble dioxolane derivative is an ethoxylate which contains an average of about 9 moles of ethylene oxide.
9. The detergent composition of claim 7 wherein the water-soluble dioxolane derivative is an ethoxylate which contains an average of about 6 moles of ethylene oxide.
10. The detergent composition of claim 7 wherein the water-soluble dioxolane derivative is an ethoxylate which contains an average of about 9 moles of ethylene oxide.
11. The detergent composition of claim 8 wherein the water-soluble dioxolane derivative is the monosulfate salt.
12. The detergent composition of claim 11 wherein the water-soluble dioxolane derivative is the ammonium salt of the'monosulfatcd dioxolane.
13. The detergent composition of claim 11 wherein the water-soluble dioxolane derivative is the sodium salt of the monosulfated dioxolane.
14. The detergent composition of claim 11 wherein the water-soluble dioxolane derivative is the potassium salt of the monosulfated dioxolane.