US3232879A - Detergent bars having good sudsing and lime soap dispersant characteristics - Google Patents

Description

United States Patent DETERGENT BARS HAVING GOOD SUDSING AND LIME SOAP DISPERSANT CHARACTERISTICS Henry Y. Lew, El Cerrito, Calif, assignor to Chevron Research Company, San Francisco, Calif a corporation of Delaware No Drawing. Filed Mar. 8, 1962, Ser. No. 178,255 12 Claims. (Cl. 252--121) This invention relates to detergent bars containing soap which do not react with the curd-forming components of hard water tottform insoluble soaps. The bars may, in addition, contain a synthetic detergent. More particularly, the detergent bars of the present invention contain a lime soap dispersing agent which is either a methyl- B-hydroxyalkyl sulfioxide, an ethyl-B-hydroxyalkyl sulfoxide, or a fl-hydroxyethyl-fi-hydr-oxyalkyl sulfoxide. The sulfoxide of the present invention inhibits or prevents curd formation of the bar when used in hard Water, and in some instances improves the foam characteristics as well.

It is well known that the use of ordinary toilet soaps in hard water gives rise to the formation and precipitation of insolublefatty acids salts, commonly referred to as lime soaps. These precipitated lime soaps tend to coagulate and form a sticky curd, which is especially noticeable in Washstands, bathtubs, and the like, Where it rises to the surface of the water and adheres around the tub or wash basin as a ring. In laundry applications the scum or curd affects the laundry tub in like manner but, in addition, adheres to the clothes. As a result, the clothes take on a gray, dingy appearance, develop spots upon ironing, and often a rancid odor. Similarly, when used for washing the hair, lime soaps are deposited thereon, giving the hair a coarse feeling and a dull appearance.

It has now been found that lime soap formation and precipitation can be substantially avoided by incorporating in the soap, e.g., a tallow soap, a minor but effective amount of a lime-soap dispersing agent which can be represented by the formula:

Xs-0I-IOHR (l H wherein R is an alkyl group of 8 to 16 carbon atoms, preferably 12 carbon atoms, and X, a member selected from the group of radicals having the formulae CH (methyl) C H (e'thyl), or HOCH CH (/3-hy droxyethyl). It has further been found that a methyl-,B-hydroxyalkyl sulfoxide, an ethyl-[i-hydroxyalkyl sulfoxide, or a B-hydroxyethyl-B-hydroxyalkyl sul'foxide herein contemplated is effective to inhibit or prevent curd formation without, in the preferred embodiments, substantially impairing the foam properties of the soap. The lime soap dispersing agent of the present invention is effective in amounts ranging from about 5 to 90, preferably to 25, percent by weight, based on soap and lime soap dispersing agent.

The soap which can be used in accordance with the present invention is not critical. Any of the water-soluble soaps in bar form normally used in industrial, laundering, and toilet applications are contemplated. As is known, these soaps can be prepared from a variety of fatty and oily materials, such as tallow, coconut oil, cottonseed oil, corn oil, soybean oil, olive oil, palm oil, lard, greases, fish oils, and the like. The cation portion of the soap is so selected as to impart sufiicient hardness to the soap to form a bar. Thus, the cation can be sodium, potassium, or nitrogen-containing, such as the ammonium soaps or those derived from triethanolamine. In general, water-soluble sodium salts of fatty acids derived from tallow and coconut oil are preferred because of the ease with which they can be formed into a bar.

As indicated earlier, the invention also encompasses 3,232,879 Patented F eh. 1, 1966 ternary mixtures of soap, of the type hereinabove described, a methyl-fi-hydroxyalkyl sulfoxide, an ethyl-B- hydroxyalkyl sulfoxide, or a 8-hydroxyethyl-fibydroxyalkyl sulfoxide and a synthetic detergent.

Indeed, it has been proposed in the past to use synthetic detergents, such as the organic alkyl sulf onates, alkyl sulfates, and alkyl benzene sulfonates, admixed with soap, to decrease its curd-forming tendency when used in hard water. Even here, however, the problem of lime soap formation and precipitation is not satisfactorily overcome.

The synthetic detergent component, like the soap, is also not critical. Broadly, it falls within the class of surface-active materials which are the water-soluble salts of organic sufonic acids and Water-soluble salts of aliphatic sulfuric acid esters. In other Words, synthetic detergents are contemplated which are water-soluble salts of organic sulfuric reaction products having in the molecular structure either a sulfonic acid or sulfuric acid ester radical.

As more specific examples of satisfactory synthetic detergent, there can be mentioned the water-soluble salts of alkyl benzene sulfonates, particularly those in which the alkyl group is a polypropylene radical or other carboncontaining chain, e.g., straight-chain radical, having an average of 8 to 15 carbon atoms in the radical; the Watersoluble salts of alkyl sulfuric acid, having 8 to 18 carbon atoms in the alkyl group; the water soluble salts, such as the alkali metal salts of sulfuric acid esters of primary normal aliphatic alcohols containing 10 to 18 carbon atoms, such as lauryl and oleyl alcohol; primary and secondary alkyl sulfates having pronounced detergent power and obtained from primary or secondary alcohols and olefins. Other examples of the synthetic detergent component include the sulfuric acid esters which are the water-soluble salts of sulfuric acid esters of polyhydric alcohols incompletely esterified with high molecular weight soap-forming carboxylic acids, such as the Watersoluble salts of sulfuric acid esters of higher molecular weight fatty acids monoglycerides, more specific examples being sodium glyceryl monolaurate sulfate and potassium .glyceryl monopalmitate sulfate.

Also useful are the water-soluble salts of sulfuric acid esters of the hydroxy ethers resulting from the reaction of an aliphatic alcohol and ethylene glycol. These compounds have the general formula:

wherein n-=8 to 20; x=l to 4; and M is an alkali metal. A typical example is the sodium salt of lauryl ether of ethylene glycol monosulfuric acid.

Another type of useful detergents are the watersoluble salts of monosulfuric acid esters of the monoethers of lower molecular weight aliphatic alcohols and glycerine. These compounds have the general formula:

wherein 11:8 to 20 and M is an alkali metal. A typical example is the sodium salt of monolauryl ether of glycerine monosulfuric acid.

Still additional examples of sulfuric acid ester synthetic detergents are water-soluble salts of sulfated higher fatty acid alkanolamides, such as the sodium salt of sulfated coconut oil fatty acid ethanolamide, and the potassium salt of sulfated tallow oil fatty acid isopropanolamide.

The method of addition of the additive of the present invention is not critical. It thus can be added to the crutcher after the soap has been made by saponification of fats. Or the additive can be added to soap chips and detergent in the amalgamator, if desired, along with other soap additives conventionally used, such as coloring agents, perfume, fillers and the like.

The ternary mixtures of the invention will generally comprise, in weight percent, based on soap, synthetic detergent, and lime soap dispersant, 5 to 90, preferably 30 to 50, soap; 5 to 90, preferably 30 to 50, synthetic detergent; and 5 to 90, preferably 10 to 40, lime soap dispersant.

In evaluating a satisfactory lime soap dispersant, a good method and the one used in the examples hereinbelow appearing is as follows: A stock solution of the test dispersant is prepared by dissolving 1 part by weight of the dispersant in 99 parts of distilled water. Stock solutions of tallow soap and of the various synthetic detergents are also prepared, again the concentration of the organic material in the solution being 1% by weight.

Tallw soap had 5.5% water, and on acidification and extraction with petroleum ether gave 85.6% fatty acids. The fatty acid component had an acid number of 202 and an iodine number of 50, and contained 2% lauric acid, 4% myrrstrc acid, 33% palmitic acid, 22% stearic acid, and 39% oleic acid.

Since the stock solutions are made up to the same concentration, the relative amount of each solution deter mines the relative percents of tallow soap or tallow soap plus synthetic detergents and dispersant for each test. For example, a 10% dispersant test is carried out as follows: Place 1 ml. of the dispersant solution and 9 ml. of the tallow soap containing solution in the bottom of a 100 ml. stoppered graduate cylinder and swirl it gently. When well mixed, dilute with 90 ml. of 334 ppm. hard water (2 parts calcium to 1 part magnesium, calculated as carbonates) at 110 F. The final hardness is 300 p.p.m. The graduate is then shaken vigorously for 15 seconds, and then allowed to stand for minutes. At the end of this time, the milliliters of curd and the milliliters of foam are measured and recorded.

The following tabulated examples illustrate the practice of the invention.

TABLE I Lime soap dispersantsbinary systems (B-hydroxyalkyl sulfoxides and soap) Ex. Compound Concen- Soap Coneen- M1. M1.

tration tration Curd Foam 1 None Tallow 100% 5 This is the base case, i.e., soap without any dispersant.

i i 2 CH3SCH2CHC10H21 Tallow O 15 In contrast to Example 1, all curd is eliminated, and three times as much foam is formed.

it B 3 CH3SCH2CHC;2H25 15% Tallow 85% O 8 The example shows the effect of increasing chain length 2 carbon atoms over Example 2. The

curd is still eliminated; the foam volume is still greater than the control (Example 1).

i i 4 OH3SO HgCH-C14Hzn 15% Tallow 85% 0 0 No curd formation occurs, though the chain length is increased by two more carbon atoms over Example 3.

r 5 CHsSC 2CHCsH11 15% Tallow 85% O 10 This example shows the eflect of decreasing chain length 2 carbon atoms (see Example 2). The

curd is still eliminated and the foam is two times the control value (Example 1).

H i 6 Cl.l3(CHe):S-CIig-CHC@lI13 15% Tallow 85% 10 10 This example using n-propyl-B-hydroxyoctyl sultoxide is unsatisfactory.

t t 7 CIIaS-CII2-C Il-C14lI29 10% Tallow .c 1 3 This shows the effect of decreasing the additive concentration as compared with Example 4. A small amount of curd forms, and there is some loam.

it P 8 HO CHZCH2S-CH2CHC1OH 10% Tallow 90% 0 10 This example shows the effectiveness of fi-hydroxyethyl-fi-hydroxyalkyl sultoxides. All curd is eliminated and good foam is obtained.

H J HO CTIQC l'I a id-C Hz-CIIC1 llp 75% Tallow 25% 0 25 Example 8.

N ow the foam is increased and no curd is formed.

TABLE IContinued Lime soap dispersants-binary systems fl-hydroxyalkyl sulfoxides and soap) Ex. Compound Concen- Soap Concen- M1. M1.

tration tration Curd Foam i i 10 HCH2CHSCHzCHC 0Hz1 5% 4:1 Tallow: 95% 2 Coconut.

Reducing the additive concentration below the preferred range (see Example 8) gives some curd, but the foam is satisfactory.

11 OI2H25SO3NEL 20% Tallow 20% 10 20 A commercial polypropylene benzene Sulfonate, a typical detergent, was used in this example.

It does not eliminate curd, although foam property is improved.

12 cinema onion-0101121 15% Tallow 85% 1 15 Ethyl-fl-hydroxyalkyl sulfoxides are also effective as shown in this example.

TABLE II Lime soap disper'sants-ternmy system (fl-hydroxyalkyl sulfoxide, soap, and a detergent) Ex. Additive Concen- Detergent Concen- Soap Concen- M1. Ml.

tratiou tration tration Curd Foam 1 None None Tallow 100% 10 5 2 .e N one Polypropylene benzene Sulfonate Tallow 80% 10 20 This example shows that the presence of the synthetic detergent has no effect on curd but increases foam volume.

(H) .C|)H 3 CHa-S-CH2-CH-C10H2r 10% Polypropylene benzene Sulfonate. 20% Tallow 0 12 In contrast .to Examples 1 and 2, the presence of a lime soap dispersant improves the curd property of the composition.

E) (311 a 4 CH3SCHz-CH-Onl12a 10% Polypropylene benzene Sulfonate. 20% Tallow 70% 0 12 I This example shows that increasing the chain length four carbon atoms does not adversely affect foam and curd properties.

r w a -5 HO C'H CH -S+CHz-CHC 1oH21 7% Polypropylene benzene Sulfonate. 20% Tallow a. 73% 0 22 Replacement of the methyl group (Example 3) with a 5- ydroxyethyl group still gives good results. Even at a lower concentration of additive there is no curd, and the foam is equivalent to .the best.

i r i l 6 H0 CHzCH2-S-CH2-CH-CrqHz1 10% Sodium Lauryl Sulfate -Q 10% Tallow .0 20

The additive of Example 5 is effective with another type of detergent, i.e., a primary sulfate.

r 7 HO CH CII2S-CH CHC11)H21 10% Sodium Paraffin Sulfonate 10% 4:1 Tallow: 80% 0 5 Coconut.

1' The paraffin group of the sulfonate is a mixture of C10 to 020 straight chain compounds. No curd appears here.

i e '8 U H0 CH2CH2-S-CH2CH-C10H21 5% Mixed Secondary Alcohol Sulfates. 10% Tallow l 10 These mixed alcohol sulfates contain alkyl groups ranging from 010 to C20 in carbon content.

. I Compared with Examples 1 and 5, shows that even at very low concentrations thls additive reduces curd by a factor of 10 and doubles the foam.

TABLE IIContinued Lime soap dispersantsternary system (fi-hydroxyalkyl sulfoxide, soap, and a detergent) Ex. Additive Concen- Detergent Concen- Soap Concen- M1. M1.

tration tration tration Curd Foam ll i 9 HO CHzCHz-S-CH2-CII-C lI 10% Ammonium Nonylphenol Tetra- 10% Tallow 80% 2 ethylene Glycol Sulfate.

Compared with Example 5, it is shown that the additive still eliminates all curd with this type of detergent.

0 11 HO CHzCHz--CHzCIIC Hz 10% 1:1 Sodium Lauryl Sulfate:Poly- Tallow 70% 0 propylene Benzene Sulionate.

This example shows the additive to function very well with a mixture of detergents.

r 11- HO CH CHzSCHzCHC H 65% Polypropylene Benzene Sulfonate- 5% 4:1OTalloutr: i 0 25 oconu Even at very high concentrations of additive, the foam properties are excellent, and no curd is formed, as shown in this example.

r r 12. HO CHzCH2- S CH2OHC H2 10% Polypropylene Benzene Sulfonate. 70% Tallow 20% 0 25 High concentrations of detergent has no adverse erieets on either foam or curd.

i R 13 S CHCHO 11 10% Polypropylene Benzene Sulfonate 20% Tallow 70% 5 12 Compared with Examples 3 and 5, it is shown that a phenyl group in place of a methyl or fi-hydroxyethyl group destroys the lime soap dispersant properties.

1] E 14---" OH3(CH2)z S-CH2CHOuH13 10% Polypropylene Benzene Sulfonate. 10% Tallow 80% 8 12 Compared with Examples 3 and 5, it is shown that a propyl group in place of a methyl, an ethyl, or B-hydroxydodecyl group destroys the lime soap dispersant properties.

ll l 15--- CH3CH2SCEgCHC 0Hz1 10% Polypropylene Benzene Sulfonate. 10% Tallow 80% Trace 12 An ethyl group in place of the methyl group does not substantially impair foam and curd-dispersing properties.

I claim: lime soap dispersant is a ,S-hydroxyethyl-fi-hydroxyalkyl 1. A detergent bar having good sudsing and lime soap dispersant characteristics, and suitable for use in hard water consisting essentially of water-soluble solid soap normally having poor lime soap dispersant characteristics, and a lime soap dispersant having the formula XSCHzCH-R (l (m wherein X is a member selected from the group consisting of the methyl, ethyl and B-hydroxyethyl radicals, and R, an alkyl radical of 8 to 16 carbon atoms; said lime soap dispersant being present in an amount of 5 to 90 percent by weight, based on it and soap.

2. A detergent bar according to claim 1, wherein the lime soap dispersant is present in an amount of 10 to 25 percent.

3. A detergent bar according to claim 1, wherein R is an alkyl radical of 8 to 12 carbon atoms.

4. A detergent bar according to claim 1, wherein the lime soap dispersant is a methyl-fi-hydroxyalkyl sulfoxide having 10 to 16 carbon atoms in the alkyl group.

5. A detergent bar according to claim 1, wherein the lime soap dispersant is an ethyl-fl-hydroxyalkyl sulfoxide.

6. A detergent bar according to claim 1, wherein the sulfoxide.

7. A detergent bar having good sudsing and lime soap dispersant characteristics, and suitable for use in hard water, consisting essentially of a mixture of a water-soluble solid soap and a water-soluble synthetic detergent salt of an organic sulfuric reaction product having in its molecular structure a member selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, said mixture having poor lime-soap dispersing characteristics and a lime soap dispersant to impart lime soap dispersing properties to the mixture, said lime soap dispersant having the formula wherein X is a member selected from the group consisting of the methyl, ethyl, and fi-hydroxyethyl radicals; and R, an alkyl radical of 8 to 16 carbon atoms; the aforesaid ingredients being present in amounts by weight percent based on soap, lime soap dispersant, and synthetic detergent ranging from 5 to soap; 5 to 90 synthetic detergent; and 5 to 90 lime soap dispersant.

8. A detergent bar according to claim 6, wherein the ingredients are present in amounts of 30 to 50 percent soap, 30 to 50 percent synthetic detergent, and 10 to 40 percent lime soap dispersant.

9. A detergent bar according to claim 6 wherein the lime soap dispersant has the formula wherein X is a member of the group consisting of ethyl, methyl, and hydroxyethyl radicals, and R is an alkyl radical of 8 to 14 carbon atoms.

10. A detergent bar according to claim 8, wherein the lime soap dispersant is a methyl-,B-hydroxyalkyl sulfoxide.

11. A detergent bar according to claim 8, v wherein the lime soap dispersant is a hydroXyethyl-fi-hydroxyalkyl sulfoxide.

12. A detergent bar according to claim 8, wherein the lime soap dispersant is an ethyl-B-hydroxyalkyl sulfoxide.

References Cited by the Examiner UNITED STATES PATENTS 2,390,295 12/1945 Flett 252121 2,407,647 9/ 1946 Bodman 252-121 2,515,120 7/1950 Harman 260607 2,654,667 10/1953 Goodhue et a1 252--161 2,658,038 11/1953 Proell 252161 2,749,315 6/1956 Faier 2521 17 2,787,595 4/1957 Webb 2S2138 3,043,824 7/1962 Oswald et a1 260-607 JULIUS GREENWALD, Primary Examiner.

ALBERT T. MEYERS, Examiner.

Claims (1)

1. A DETERGENT BAR HAVING GOOD SUDSING AND LIME SOAP DISPERSANT CHARACTERISTICS, AND SUITABLE FOR USE IN HARD WATER CONSISTING ESSENTIALLY OF WATER-SOLUBLE SOLID SOAP NORMALLY HAVING POOR LIME SOAP DISPERSANT CHARACTERISTICS, AND LIME SOAP DISPERSANT HAVING THE FORMULA