|Publication number||US2734870 A|
|Publication date||Feb 14, 1956|
|Filing date||May 21, 1951|
|Publication number||US 2734870 A, US 2734870A, US-A-2734870, US2734870 A, US2734870A|
|Inventors||Allen :H. Lewis|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (10)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent rNON-SOAP SYNTHETIC DE'I-ERGENT? BAR AllenlH. Lewis, Berkeley, Calih, "assignor "to California Research Corporatiom sanFrancisco, can, a corpo- 'ra'tionofDelaware No Drawing. Applica'tion Mayll, 1951, Serial N 0. 227,507
3 Claims. (CL 252-161) The invention t relates to a new and useful detergent composition. More particularly, it relates-to a "detergent composition which can the cast, "molded, or framed in conventionalmanner to-produce a detergent bar having superior properties.
*Inrecent years synthetic detergents, particularly the alkylzarylsulfonate detergents of "the type described in 'Lewis' U. S.'Patent No. 2,477,383, have won wide ac- "ceptance in household applications and-very large volumes of these materials are currently manufactured and sol'd. These synthetic detergents have been prepared for the consumer in powdered or granular form andsubstantially all of these materials-have-been marketed-in that form. The desirability of producing a synthetic detergent bar has long been recognized and extensive experimental workdiasbeendirected tothis end as'evidenced, for nexample, by yMcCutcheons paper entitled .Synthetic Detergents r in Barv Form, Soap, December 1949, page 3-3ret: seq. Despite: intense "effort in this .direction by a dargemumber of skilled research workers, no satisfa'cto'ry tsynthetio detergenti-bar-has beenproduced whichhas met irvithwvide consumer" acceptance. The 1 principal. problem encountered in an 'eftort to produce asynthetic; detergent bar is that of finding a binder which would hold the active detergent components together and give the bar suitable physical characteristics. An acceptable bar should be firm, cohesive, smooth and pleasant to the -touch,'lather and suds well in hot and coldwatenand .be resistant to water in the sense that it does notbecome .soft and slimy in use or wastev away rapidly when wet,
'Tparaflin Waxand 70.to 30 parts by weightof an'organic sulfuric react-ion'product type-detergent which is soluble in paratfin wax at a temperature inthe range 200 350 :F. can be cast,-mol'ded,'orframed to form a synthetic'detergent bar having'excellent physicaland de'tersive prop- Thesecompositions are produced by melting paraflin wax-andhea'tingit to a ternperature in'therange 200 to 350" "F., preferably 250'to 325 F., -and I stirring the organic 'ssulfuric reaction product type detergent into the J hot Lmolten waxto form a'clear, transparent liquid solu- ;tion, and cooling the ;-solution until it solidifies.
-..In :a preferred embodiment of the invention, 1thede- .tergent .con3position .contains -40 -to 60 ;parts .by weight mt paraflin wax.andinaddition.to the 'wax .and organic sulfuric reaction product type detergentasmall amount "ice not --exceeding about 10% "by weight based on the total detergent composition of a polar organic hampo'u'rtd,
especially of a higher fatty-acid.
ln pro'ducing the'preferred composition, 1 the wax-is 5 melted'and heated to atem'peraturein therange about 250 to 325 F. as-indicated above; the higher fatty-acid is added to the hot 'molten' wax, and-the'organic'sulfuric reaction product type detergent is' then 'dissolvedidthe hot mixture.
Three" important advantages attend 'the' use of anorganicpolar'eompound in this manner. Fir'st; the organic sulfuric reaction product type detergent dissolves "in the wax much more readily and much more rapidl'ywithconsiderably less agitation toprodnce'asolution of lowered viscosity; second, any tendency of 5 the organicsulfuric reaction-productto'drop out ofsolution'during cooling of the hot mixture and'toa'gglomerate, 'formingapp'reciably large particles-of' detergentmaterial'in" the bars produced and thus to render them macroscopicallyheterogeneous, is suppressed; and, third, the solid detergent" bars produced are plasticized by thepolar material. I
The compositions of bothofthe'above embodiments derive theirprimary valuable.characteristicsffrom the wax and organic sulfuric reaction producttype deter- 25 .gent components. Thepresence of the polar-material considerably simplifiesthe process of makingthe detergent compositions and enhances the already thoroughly acceptable properties of thejp'roduct. The compositions of both ofthe above embodiments-have areasonable tolerance for the incorporation of inorganic builders which, although insoluble, maybe-dispersed in the .bar to improve the over-alldetersive action; operable ha'rs may contain up to, about. 25 by weight of. any: of .the usual inorganic builders such as alkali metal esulfates, alkali metal phosphates, alkali metal. polyphosphates and alkali metal silicates. -tlt-ispreferable, however, to.ke ep the inorganic salt content of the finished bar below about 12% of its total weightin ordernto-avoid a tendency towardfrosting, -i. .-.e., the formation -ofinorganicfsalt 40 crystals on its surface.
.Thepreferred wax for use in compoundingathe compositions of theri-nvention is. preferably -:a paraffin wax derived from";-,petroleum shaving a -melting ,-.point .above ..about .-125 -F. andhaviug a relatively. low oilcontent, desirably-below about 2% by-weight. The ware may-be either crystalline or amorphousand its melt-ing point may :rangeupto-about 175 F. Theordinaryede-oiledpetroieum waxes of commerce are entirely. satisfactory for compounding-the detergent compositions of thei-nvention. .It should be understood that modificationsof the characteristics ot, paraffin -Wax by the incorporation -,-of small amounts; of vegetable waxes -is -.not precluded.
, -As tindi'cated ahove, theactive detersive--component=-of the lcomposition is a water-soluble salt' of ana-organic'isul- :furioreaction producbwhichis soluble in paraflin-wax -at a -temperature in the range -about- 200 350? F. =-These:prodnets are characterized by alarge. hydrophobic group con- -s-isti-ngsalmostentirely-of hydrocarbon material and the smaller hydrophilic sulfuric acid residue. The metal-co"mponent of a s-alt of the organist sulfuric reaction product is ordinarily :sodiurn, but otheralkalimetals and: alkaline earth metals,especially magnesium, may: beipresenttasdhe metallic component. -Materials ofithis general description have .the. common property-of remaining highly dispersed in .thewvax matrix when thetcompositionis coldgso th'at .the finished solid is characterized by macroscopic -zhomogeneity.
v.A very-considerable numberwof organic sulfuric-reaction .product type .-synthetic detergents .-aresdescni bedninnthe ,vliterature andvsev er-al of -.these nmaterials tare? articleswof com-mercerproduced 'incsubstantial -volume;.-tfor 'texample .alkyL-sulfates containing -1-0-.-to T20.carbon tatomsainathe alkyl group, alkyl sulfonates containing to carbon atoms in the alkyl group, sulfated monoglycerides of coconut oil fatty acids and especially alkyl aryl sulfonates containing 10 to 20 carbon atoms in the alkyl side chain. While these materials have similar physical properties in that they are water soluble and exhibit detersive and wetting properties and a structural similarity in that they are all characterized by a large hydrophobic group consisting almost entirely of hydrocarbon material and a smaller hydrophilic sulfuric acid residue, they are not all suitable for use as components of the compositions of this invention. To be useful here the organic sulfuric reaction product type detergent must be soluble in hot paraffin wax.
. Some of these materials are soluble and some are not.
Without exception it has been found that those which are soluble in the wax remain highly dispersed in the wax matrix when the solution is cooled until the wax solidifies and that the solid is macroscopically homogeneous. The solubility of any particular organic sulfuric reaction product type detergent, and hence its suitability for use in composing the compositions of this invention, is readily determined by melting paraffin wax, heating it to about 300 F. and stirring the detergent into the wax. Suitable detergents dissolve in the wax forming a clear transparent liquid solution at concentrations above 30% by weight.
Organic sulfuric reaction product type detergents having a branched alkyl group containing 10 to 20 carbon atoms, especially the alkyl aryl sulfonates described in Lewis Patent 2,477,383, are highly soluble in paraffin wax. The Lewis detergent is prepared by polymerizing propylene, separating a polypropylene fraction boiling from about 325 to 520 F., alkylating a mononuclear aromatic hydrocarbon such as benzene, toluene or xylene with the polypropylene, sulfonating the alkyl aromatic hydrocarbon product and neutralizing the resultant sulfonic acid with an alkali metal hydroxide or with an alkaline earth metal hydroxide.
The organic polar material which is desirably incorporated in the preferred composition of the invention is preferably a higher fatty acid, i. e., aliphatic monocarboxylic acid containing 10 to 20 carbon atoms, for example stearic acid, oleic acid, palmitic acid and lauric acid.
As indicated above, the wax-synthetic detergent compositions of the invention will tolerate the addition of fairly substantial amounts of inorganic builders without too much sacrifice of their desirable bar-form properties. For example, the alkali metal carbonates, phosphates, borates, and silicates which are generally known as alkaline builders can be tolerated up to a maximum amount of about by weight of the total bar. Neutral builders such as sodium sulfate and sodium chloride can be tolerated in similar amounts. Those skilled in the art will recognize that perfume, coloring matter and fillers such as infusorial earth and bentonite and. the allied group of clays may be incorporated in the finished bar. It must be recognized that the incorporation of insoluble material will proportionately increase the viscosity of the molten mix during the preparation of the product. The term consisting essentially employed in the appended claims is used in the sense that conventional fillers, builders, perfumes, etc., may be added to the waxdetergent compositions.
To prepare the compositions of the following examples paraffin wax was melted and heated to a temperature in the range about 250 to 325 F., and preferably in the range 275 to 300 F., and the synthetic detergent was stirred into the wax to dissolve it. At temperatures below 200 F. the rate of solution and solubility of the detergent in the wax are low and the detergent-wax mixtures prepared at such temperatures tend to be macroscopically heterogeneous when cooled. At temperatures much above 300 F. the synthetic detergent tends to char, and color of the ultimate product is poor. The temperature preferably should not exceed 325 F. When only wax and the synthetic detergent were employed in making the detergent composition, extensive agitation and the application of shearing force to the mixture was required to achieve homogeneity of the product. The addition of a higher fatty acid to the molten wax prior to the addition of the synthetic detergent greatly facilitated the dissolving of the detergent and brought about a marked reduction in the viscosity of the solution. After the detergent is dissolved in the wax the molten mixture may be poured into individual bar molds, or poured into a conventional frame and cooled until the mass solidifies, after which the mass is cut into bars. Alternatively, the mass may be cooled to a temeprature just below its solidification point and then extruded or pressed into bars.
Example I 70 parts by weight of de-oiled paraffin wax having a melting point of 125 F. and an oil content below 2% by weight were heated to 310 F. 30 parts by weight of a sodium alkyl benzene sulfonate containing 12 to 15 carbon atoms in the alkyl chain were dissolved in the wax. Solution was accomplished by stirring the mixture for about 6 minutes. The fluidity of the solution was approximately that of hot molten wax. The solution was poured into a metal bar mold and cooled to room temperature. The bar separated from the mold without adhering to the metal. The bar was a light buff color and was similar to wax in consistency. The bar was smooth and pleasant to the touch, was perfectly homogeneous to visual inspection, and floated in water. When the bar was worked with the hands in the usual manner with hot or cold water, it lathered, but rather poorly.
Example 2 60 parts by weight of the paraflin wax of Example 1 were heated to 300 F. 40 parts by weight of sodium polypropylene benzene sulfonate containing 12 to 15 carbon atoms in the polypropylene radicals were dissolved in the molten wax. The wax was cast in bar form as in Example 1. The lathering properties of this bar were considerably better than those of the bar in Example 1. The specific gravity of this bar was slightly less than 1.
Example 3 47.5 parts by weight of the paraffin wax of Example 1 were melted and heated to 300 F. 52.5 parts by weight of a mixture of sodium polypropylene benzene sulfonate containing 12 to 15 carbon atoms in the polypropylene groups and sodium sulfate were incorporated in the molten wax. The ratio of sulfonate to sulfate in the solute was 60:40. The liquid dispersion produced had a considerably higher viscosity than the solutions of Examples 1 and 2 due to the salt content. The mixture was barely pourable at 300 F. The mixture was cast in bar form as in Example 1. The bar lathered well in hot and cold water, but frosted slightly after wetting because of the sodium sulfate content.
Example 4 47.6 parts by weight of the wax of Example 1 were melted and heated to about 300 F. 9.6 parts by weight of palmitic acid were dissolved in the molten wax and then 42.8 parts by weight of a mixture of sodium polypropylene benzene sulfonate containing 12 to 15 carbon atoms in the polypropylene radicals and sodium sulfate were incorporated in the wax-acid solution. The ratio of sulfonate to sulfate in the latter solute was :10. The resulting dispersion was highly fluid and the apparent rate of solution of the sulfonate in the wax was rapid, the sulfonate apparently dissolving completely after 2 minutes of stirring. The resulting mixture was cast in bar form. The bar lathered well, but the foam broke more rapidly than the foams produced by the bars in Examples 1 to 3 inclusive, presumably because of the high fatty acid content of the bar.
Example 5 52.4 parts by weight of the parafiin wax of Example 1 were melted and heated to about 300 F. 4.8 parts by weight of palmitic acid were dissolved in the molten wax and then 42.8 parts by weight of the sulfonate-sulfate mixture of Example 4 were incorporated in the wax-acid solution. The resultant mixture was cast in bar form. The resultant bar lathered well and the foam was more stable than the foam produced by the bar of Example 4, but not quite as stable as the foam produced by the bar of Example 2.
Example 6 56.2 parts by weight of the paraifin wax of Example 1 were melted and heated to about 300 F. One part by weight of palmitic acid was dissolved in the molten wax and then 42.8 parts by weight of the sulfonate-sulfate mixture of Example 4 were incorporated in the wax-acid solution. The presence of the palmitic acid in this small amount noticeably increased the apparent rate of solution of the sulfonate and lowered the viscosity of the resulting mixture. The final mixture was cast in bar form. The bar lathered well in both hot and cold water and the foam produced was apparently identical with the foam produced by the bar of Example 2 with respect to stability.
Example 7 52.3 parts by weight of the wax of Example 1 were melted and heated to about 300 F. 1.8 parts by weight of palmitic acid were dissolved in the molten wax and then 40.6 parts by weight of the sulfonate-sulfate mixture of Example 4 were incorporated in the solution. 5.3 parts by weight of glycerine were incorporated in the resultant mixture. The final mixture was cast in bar form. This bar was similar in all of its properties to the bar produced in Example 6.
Example 8 57.7 parts by weight of a de-oiled paraflin wax having a melting point of 143 F. were melted and heated to about 300 F. 42.3 parts by weight of the sulfonatesulfate mixture of Example 4 were incorporated in the molten wax. The mixture was cast in bar form. The bar lathered well in both hot and cold water.
Example 9 35 parts by weight of the paraflin wax of Example 1 were melted and heated to about 300 F. 5 parts by weight of palmitic acid were dissolved in the molten wax and then 60 parts by weight of the sulfonate-sulfate mixture of Example 4 were incorporated in the solution. The final mixture was cast in bar form. This bar had excellent lathering properties, and was apparently equal in this respect to a good grade of toilet soap. During prolonged use, the bar wore away smoothly and showed no tendency to soften or crumble when exposed to the usual conditions of household use.
Example 10 45 parts by weight of the paratfin wax of Example 1 were melted and heated to about 300 F. 5 parts by weight of stearic acid were dissolved in the molten wax and then 50 parts by weight of an alkyl aryl sulfonate prepared by alkylating benzene with a propylene polymer fraction boiling over the range about 360 to 520 F., sulfonating the alkylate, and neutralizing the resultant sulfonic acid with sodium hydroxide, were dissolved in the wax-acid mixture. The resultant solution was cast in bar form. This bar had excellent lathering properties and was durable in ordinary household use.
The bars prepared in all of the foregoing examples were macroscopically homogeneous as they left the mold and all of them retained their homogeneous appearance throughout prolonged use, with the exception of the bar produced in Example 3 which showed a tendency to frost. The materials of which each of the exemplified bars are formed do not appear to wet the surfaces of metallic molds and are readily freed from the mold when cooled. The exemplified bars may be remelted and recast without loss of homogeneity and apparently without change in any of the physical or chemical properties of the composition.
1. A firm, cohesive and macroscopically homogeneous detergent bar consisting essentially of 40 to 60 parts by weight of parafiin wax, 2 to 5 parts by weight of a fatty acid containing 10 to 20 carbon atoms per molecule and 60 to 40 parts by weight of a mixture of water-soluble alkyl aryl sulfonates, the alkyl groups being propylene polymers containing predominantly from 12 to 15 carbon atoms.
2. A firm, cohesive, macroscopically homogeneous detergent bar consisting essentially of 40 to 60 parts by weight of paraffin wax, 60 to 40 parts by weight of an alkyl benzene sulfonate detergent having 10 to 20 carbon atoms in its alkyl group, 1 to 10 parts by weight of a fatty acid containing 10 to 20 carbon atoms per molecule, and from 1 to 25 parts by weight of a water-soluble inorganic builder.
3. A process for producing a macroscopically homogeneous detergent bar which comprises forming a mixture of molten paraffin wax and a higher fatty acid, heating the mixture to a temperature in the range 250 to 325 F., dissolving an alkyl benzene sulfonate detergent having 10 to 20 carbon atoms in its alkyl group in the hot mixture and cooling the solution to form a macroscopically homogeneous solid, the proportions of the components in the solution being 40 to 60 parts by weight of wax, 1 to 10 parts by weight of a fatty acid containing 10 to 20 carbon atoms per molecule and 60 to 40 parts by weight of sulfonate.
References Cited in the file of this patent UNITED STATES PATENTS 2,175,285 Duncan Oct. 10, 1939 2,356,903 Wood Aug. 29, 1944 2,462,758 Malkemus Feb. 22, 1949 2,653,913 Van Dijck Sept. 29, 1953 2,678,921 Turck May 18, 1954 FOREIGN PATENTS 583,028 Great Britain Dec. 5, 1946 592,206 Great Britain Sept. 10, 1947
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