US2868731A - Process of making nonsoap detergent bars and product - Google Patents

Description

vofthe mill and the screw of the plodder.

remove PROCESS OF MAKING NONSOAP DETERGENT BARS AND PRODUCT Lloyd F. Henderson, Fair Lawn, and Francis E. Carroll,

Glen Rock, N. J., assignors to Lever Brothers Company, New York, N. Y., a corporation of Maine No Drawing. Application October 14,1954 Serial No. 462,387

9'Claims. '(Cl. 252- 117 This invention relates to a process for the manufacture Soap ordinarily is shaped into bars by. milling and detergents also require plasticization before they can be shaped lnto bars. However, many nonsoap detergents cannot be milled and plodded in the presence of so much water because they become sticky and adhere to the rolls In order to form a synthetic detergent bar, it is necessary to incorporate some other substance in the mixture to make it workable. I

,Many substances have been proposed as plasticizers for nonsoap detergents. However, most of these materials disadvantageously affect other properties of the bar. Other substances inhibit sudsing or produce a cake which has a poor texture or which is too brittle to withstand normal usage.

In addition to these problems, the physical properties of nonsoap detergents make their formation into bars dlfiicult. Many nonsoaps particularly the anionic'types contain electrolytes which are difiicult and expensive to These, particularly in the presence ofwater, have a marked effect on the cohesive properties of the active materials, so that a binder substance must be incorporated in the composition. In other cases, the nonsoap detergent is too soft to retain the shape of abar. Also, many nonsoap detergents are more soluble in water than soap and'dissolve rapidly even when compressed in a dense cake or bar. Unless the rate of solution of the nonsoap bar can be kept comparable to the rate of solution of bar soap, the nonsoap detergent bar is at a competitive disadvantage.

In accordance with the instant invention, non-soap detergent compositions are provided, adapted for formation intobars, and plasticized by a small amount of a high molecular weight aliphatic carboxylic acid. Such acids improve the appearance, texture and feel of the bars.

As an optional supplemental plasticizer, there can be used an ester of an aliphatic polyhydric alcohol and a high molecular weight aliphatic carboxylic acid. These .esters serveas binders in the finished bar and aid in imparting a good texture to the bar and reducing its rate of solution in water The water-soluble alkali metal soaps of the abovedescribed fatty acids are also supplemental ingredients. Soaps are used both as'comparatively cheap fillers and for their waxy character which gives them'good binding qualities. The more insoluble the soaps are, the more satisfactory.

- The aliphatic carboxylic acids'which are employed as binders in the free acid form (and also as the esters of aliphatic polyhydric alcohols), have a relatively high molecular weight to take advantage ofthe waxy and lubricant United States Patent :of nonsoap detergent bars and to the nonsoap detergent .bars which are obtainable by such a process.

gharacteristios 9f such acids; They are preferablysolids 1 2,868,731 Patented Jan. 13, 195 9 at normal atmospheric temperatures but should soften,

under pressure at plodding temperatures, i. e., from 100 to 200 F. The desired characteristics are possessed by the aliphatic saturated and unsaturated straight and branched chain carboxylic acids having from about twelve to about twenty-five carbon atoms, of which the following are satisfactory and exemplary: lauric acid, lignoceric acid, myristic acid, arachidic acid, behenic acid, palmitic acid, stearic acid, octadecenoic acid, erucic acid, elaeostearic acid, palmitoleic acid, dihydroxystearic acid, and the mixed higher fatty acids derived from naturallyoccurring oils and fats such as coconut oil, lard, tallow, palm kernel oil, myristica fat, stearin, seed fats, linseed oil, cotton seed oil, hydrogenated fish oils, whale oil, tall oil, rosin, greases, soybean oil, olive oil, babassu-oil,

castor oil, peanut oil, and mixtures ofanysuch acids.

Acids liquid at normal atmospheric temperatures can be used in small amounts, preferably with an amount of a solid acid so that the acid mixture is solid at normal atmospheric temperatures.

The esters are formed by reaction of any of the above acids with polyhydric alcohols having two or more hydroxyl groups,.and from two to about twenty-five carbon atoms, such as ethylene glycol, diethylene glycol,'triethylene glycol and higher polyethylene glycols, glycerol, erythritol, arabitol, adonitol, xylitol, mannitol, sorbitol and dul'citol. Mixtures of alcohols and fatty acids may be used in formulating the esters. The esters preferably are solids at normal atmospheric temperatures but should soften under pressure at the plodding temperatures, i. e., 100 to 200 F. Esters liquid at normal temperatures can be used, in the same manner as the acids, as described above.

Mixtures of the acids andof the acids and esters may be employed in the nonsoap detergent bars of the invention. The mixture of the high molecular weight acid and ester should soften sufliciently under the conditions employed in compressing and shaping the composition to plasticize the same.

The amount of the carboxylic acid and its mixtures with the esters is not critical. A small amount, up to 40% by weight of the composition, would be used, suf ficient to plasticize the nonsoap detergent composition. The lower limit of acid which is effective depends to a large extent on the amount of electrolyte in the composition. The less the electrolyte, the less acid required. 0.5% free acid would be effective when little electrolyte is present. There is usually several percent electrolyte in most commercially available synthetic organic detergents suitable for use in a bar, and in such cases some plasticizing effect will be obtained by as little as 0.5% of the acid. The actual amount will depend upon the acid, the detergent and the temperature and pressure under which the composition is compressed and shaped.

. The plasticizing effect can be enhanced by including a small amount of the high molecular weight fatty acid ester of a polyhydric alcohol. Amounts within the range from 2 to 10% acid are preferred, and up to one-half of this amount can be ester. Amounts up to 40%, of which no more than one-half is ester, may be employed, but experience has indicated that although amounts in excess of 20% can be used, such amounts give no added improvement and, therefore, will be wasteful.

The composition of the invention ordinarily will contain at least 20% upto about nonsoap detergent, from 0.5% up to approximately 40% of the high' molecular weight fatty acid or; acid-ester mixture, from-0 to about 40% of a water-soluble alkali metal fatty acid soap, and from 0 to about 60% fillers, parafiin wax, pigments and perfume. Such a composition can be worked at temperatures in the range from-: 0?-1t0,- 2 QQ F., the temperatures ordinarily encountered in soap plodding procedures.

It is desirable to keep the moisture content of the composition at a minimum in order to prevent the detergent from becoming sticky. The moisture content of the mixture should be reduced prior to compressing and shaping to within the range from about 0.5 to about 2% by weight of the composition. Approximately 2% moisture is normally the maximum that is permissible, although amounts as high as 5% may be tolerated when certain detergents are employed.

The nonsoap detergents used in making the bars of the invention are well known to the art and do not per se form any part or" the invention. The nonsoap detergent should be a solid at normal atmospheric temperatures, and is selected from the well known classes of these substances, including anionic and nonionic detergents.

A particularly preferred class of detergents are the aliphatic oxyethane amide sulfoacetates having the general formula:

where R is an aliphatic hydrocarbon radical which may be either saturated or unsaturated having at least seven and preferably from eleven to seventeen carbon atoms, and can be a single radical or mixture of radicals such as would be obtained from a fatty oil or fat. Acids such as palmitic, stearic, oleic, caprylic, myristic, lauric, alone or in admixture such as in palm oil fatty acids, and coconut oil fatty acids can be used in these detergents. M is a salt-forming cation whose salt with the sulfated alkanolamide is water-soluble and can be an alkali metal such as sodium, potassium and ammonium or an organic amine such as triethano-lamine, isopropanolamine, morpholine, diethanolamine, monoethanolamine and triisopropanolamine. For further details see U. S. Patent No. 2,184,- 770 to Katzman, dated December 26, 1939.

It is especially advantageous to utilize these sulfatecl alkanolamide detergents in combination with alkyl aryl sulfonates.

A preferred class of alkyl aryl sulfo-nates are the phenyl polypropylene sulfonates described in U. S. Patent No. 2,477,383 to Lewis. These are phenyl alkanes in which the alkyl carbon at the benzene ring is tertiary:

where R and R taken together with the remainder of the polypropylene radical form an alkyl group having an average molecular weight corresponding to from about twelve to about fifteen carbon atoms, and M is as above.

Also useful are the sodium and potassium tertiary octyl benzene sulfonates, the sodium and potassium keryl benzene sulfonates obtained by condensing kerosene with benzene and then sulfonating the product, sodium nonyl benzene sulfonate, potassium nonyl toluene sulfonate, sodium dodecyl toluene sulfonate, potassium dodecyl benzene sulfonate and sodium ethyl hexyl benzene sulfonate.

The alkyl aryl sulfonates in conjunction with the carboxylic acid minimize the sliming characteristics of the bar. This is because together the carboxylic acid and the alkyl aryl sulfonate reduce the high solubility and increase the cohesive properties of the sulfated alkanolamide detergent.

The amount of the supplemental alkyl aryl sulfonate in combination with the sulfated alkanolamide may range from 2 to 15%. Generally, increasing the amount from 5 to 10% does not appreciably improve the sliming characteristics but does improve the solubility characteristics; therefore, the optimum amounts are from 3 to 10%.

Additional classes of anionic detergents are the fatty alcohol sulfates and the fatty alcohol sulfonates, usually in the form of the water-soluble alkali metal, e. g., sodium, potassium and ammonium, or organic amine salts, such as sodium lauryl sulfate, sodium stearyl sulfate, sodium salt of sulfated ethanolamide of oleic acid, sodium palmitic methyl tauride, dihexyl ester of succinic acid, disodium N-octadecyl monoamide sulfo-succinate, sodium salt of coconut oil fatty alcohol sulfate, sodium oleyl methyl tauride, and the oleic acid ester of hydrooxyethane sodium sulfonate.

Nonionic nonsoap detergents may also be used. Some of these are liquids, and soft waxes, and would be used with solid anionic or nonionic detergents. As exemplary there can be listed particularly polymerized ethylene and propylene oxide condensates and the reaction products thereof with sulfonamides, amides, alcohols and fatty acids such as mixed polyoxyethylene-1,2-propylene glycols (the Pluronics, see U. S. Patents Nos. 2,674,619, and 2,677,700) sorbitan polyoxyethylene monostearate, polyethylene glycol dodecyl thioether, lauramidopolyoxyethylene glycol, stearylsulfonamidopolyoxyethylene glycol, polyoxyethylene propylene glycol stearate, and polyoxyalkylene glucose tetrastearate, and condensation products of alkyl phenols and ethylene and/or propylene oxide, the alkyl radical having from five to about fifteen carbon atoms, such as tert-octyl and nonyl phenol condensed with five to twelve moles of ethylene oxide.

The composition may also contain water-soluble fillers, such as sodium chloride, sodium sulfate, sodium silicate, polyphosphates such as tetrasodium pyrophosphate, sodium tetrapolyphosphate, and pentasodium tripolyphosphate, as well as pigments, such as titanium dioxide and perfume. Paraifin wax may be added. Various fillers and pigments ordinarily employed in soap bars may be used in the formulations of the invention, and since these are well known tothe art, further details are unnecessary.

The nonsoap detergent composition may be formed into a bar or-cake by conventional soap milling and plodding equipment, and these are well known to the art. It

is usually preferable to keep the plodding temperature in the range from to F. in order to reduce the possibility of discoloration or decomposition of the components of the bar but temperatures up to 200 F. can be used. If the plodding is to be carried out at temperatures below 110 F., larger amounts of high molecular weight acid or acid-ester mixture may be required than at temperatures within the preferred range.

It is usually desirable first to compress the nonsoap detergent composition in the form of ribbons or short pieces in a soap mill; thereafter, the ribbons or pieces of nonsoap detergent composition are fed into the plodder hopper, from which they are led into the screw of the plodder. This screw forces the composition forward toward the plodder compression cylinder, at the end of which there is a perforated baffle plate. During compression of the composition considerable heat maybe generated and this is dissipated or controlled by surrounding the screw and compression cylinder with a cold water jacket. At the end of the cylinder there is an orifice, from which the composition emerges continuously in'bar form. The shape of the orifice is determined by the desired shape of the finished cake. Thetemperature of the orifice may be controlled by a suitable heater, usually electric, in order to permit the extrusion of a smooth and polished continuous bar.

,A pre plodder or'refiner may also be employed which discharges into the plodder and which may act-to increase the capacity of the plodder. In this arrangement the composition is fed to the refiner, from which it is discharged through a perforated plate or screen and is broken Example Number (percent by up by a revolving blade. It is then fed to the finishing In edients Weight) plodder, which, if desired, may be operated conveniently I under a vacuum at the inlet end. 5 7 8 9 Q a See Soaps and Detergents," Thomssen and McCutcheon, MacNair-Dorland Company, 1949, pp. 195-207 for otal Sohds 62 69.5 additional information on conventional bar soap making Active.... (39) (42) (44. (45) techniques involving milling, plodding and shaping, by (23) (2 (25-5) means of which techniques the nonsoap compositions of 10 Total Solids 10 (4 2.5

r Acti e 8.5 .25 2.13) the invention can be shaped into bars. I Nonalctive (L 5) (0.75) (a 37) The followmg examples Illustrate various nonsoap Stearic Acid 6.67 6.67 6.67 detergent formulations in accordance with the invention: $3 $3 $8 Examples 1 Paraflin Wax i2 15) I 15 n Nonsoap detergent bars were prepared using a mixture 81;? 8: 8f

of sodium lauryl oxyethane amide sulfoacetate (Emco) and alkyl benzene sodium sulfonate (Ultrawet K). These formulas were milled and plodded at 110 F.:

1 Sodium lauryl oxythane amide sulfoacetate. 2 Alkyl benzene sodium sulfonate.

Example Number (percent by weight) Ingredients Emco Total Solids 52 57 62 52 57 62 Active (33) (36) (89) (33) (36) (39) N onactive (19) (21) (23) (19) (21) (23) Ultrawet K Total Solids 15 15 10 Active.-- (12. 75) (12. 75) (8. 5) (12. 75) (12. 76) (8. 5) N onaetive- (2. (2. 25) (1. 5) (2. 25) (2. 25) (1. 5) Stearic Acid 10 5 5 10 8 10 Glycerol Monostearate 5 2 5 Sodium Stearate 15.0 15.0 15. 0 15. 0 10.0 10. 0

5.0 5. 0 5. 0 1.5 1.5 1.5 1.5 1.5 1.5 0. 75 0. 75 0. 75 0. 75 0. 75 0.75 Perfume 0. 75 0. 75 0.75 0. 75 0.75 0. 75

1 Sodium lauryl oxyethane amide sulfoacetate. 2 Alkyl benzene sodium sulionate.

These bars were then evaluated by standardized soap bar test procedures and the followmg data taken:'

Example Number Com- Test mercial Soap 1 2 3 4 5 6 Bar 1 Hand Lather Suds E E .E l E E G I Hand Lather Sliminess and Stringiness G F F G 1 G G G Y Soaking in 300 cc. H2O for 2 hours at 85 1 Evaluating for Disintegration and Cracking F F G F 1 F G F Machine Lather Test in 800 p. p. In. Water: I 7

Height of Suds after 5 min. at 105 F. (Inches). 2 3% 3% 2% 5 5 1 Soln rate in g./min 1.4 2.0 2.0 1. 2 1.7 1.6 3. 5 Machine Lather Test in 300 p. p. In. Water:

Height of Suds after 5 min. at 85 F. (Inches) 2% 2% 2% 2% 5% 5% 0 Soln rate in g./min 1. 4 1. 2 0. 97 1. 1 1. 3 1. 3 2. 32

E=excellent; G=good; F=fair; P=poor. 1 V 1 Data typical of soap, not taken at same time as other data.

Examples 7 to 10 Nonsoap detergent bars were prepared in accordance with the following formulation. These formulas were milled and plodded at 110 to 130 F. I

The hand and machine lathering, soaking and sliminess characteristics of thesebars are listed below.

' Example Number Com- Iype Test mereial 1. s

' 7 8 9 10 Bar Hand Lather Suds Volume E E G G G Hand Lather 'Sliminess and Stringlness l G G F F G Soaking Test (2 hours at F)... F G G G )3 Machine Lather Test in 300 p. p. 111. Water at F.:

Helgihlt (111i Suds after 5 minutes in c as 3% 2% 2% 3% Soln rate in g./min 0. 9 1.6 1. 4 2. 2 3. 5 Machine Lather Test in 300 p. p. in. Water at 85 F.:

Height of Suds after 5 minutes in inches 1% 1% 23 3% 0 Soln rate in g./min 0. 8 0. 9 0.8 1. 2 2. 32

E=excellent; G-good; F=fair. 1 Data typical of soap, not taken at same time as other data.

7 The above detergent bars gave a suds volume equal to or better than soap, 'had'a minimum of sliminess and stringiness, a lower solution rate than soap, and a resistance to soaking that was equal to or better than soap.

The sudsing was appreciably better than that of: soap.

Examples 11 to 13 The fOllOWing formulations were prepared:

Example Number 10 (percent by weight) Ingredients Sodium Lauryl Oxyethane Amide Sulfo- 15 acetate (Emco) Paste Solids (63% active)-.. 79. 25 68. 75 59. 75 Stearic Acid 5.0 12. 0 18. 0 Coconut Oil Fatty Acids 2. 5 6. 0 9. 0 Sodium Stearate 11. ll. 20 ll. 20 Water 1.3. 1.3 1.3 TlOz 0. 75 0. 75 0. 75 Machine Lather Test in 300 p. p. In. Water:

Height of Suds (inches) after 5 minutes at 20 105 F 6% 6 Soln rate in g./min 3. 2 1. 6 0.6

The above formulations were milled and plodded at 110 to 130 F., giving bars which were quite soap-like in appearance and texture.

The hand lathering characteristics of the above bars were satisfactory. As the amount of free fatty acid was increased relative to the Emco, the volume of lather and solution rate and sliminess decreased. No. 12 is the preferred composition from the standpoint of these qualities, No. 13 having a slightly less volume of lather, lower solution rate and less sliminess and No. 11 a greater volume of lather, but a higher solution rate and greater sliminess.

The nonsoap detergent bar formulations of the invention can contain not only the free fatty acid plasticizer and esters thereof, but also the water-soluble alkali metal, e. g., sodium, potassium or ammonium, soaps of such fatty acids. These materials are incorporated separately and retain their identity in the finished composition, due to the small amounts of water contained therein which are insufficient to solubilize the free fatty acid and effect ion exchange in situ. The free fatty acid serves as a plasticizer for the detergent composition, whereas the water-soluble soap of such fatty acid serves to improve the soaplike feel and texture of the bar as well as its lathering properties, as well as having a plasticizing and binding action upon the composition. These components are present independently of each other and serve different functions. Whereas the free fatty acid is an essential ingredient of the composition, the watersoluble soap of such acid is only an optional component.

The nonsoap detergent bars of the invention are characterized by the desirable appearance and texture of soap, 55 but with the superior sudsing and detergent properties in hard water characteristic of nonsoap detergents. They do not waste away rapidly in use but have a slow rate of solution in water,'suitable for normal detergent action. They do not become slimy or greasy when wet.

it will be understood that numerous modifications obvious to those skilled in the art may be made in the invention and that the scope thereof is not to be limited, except as set forth in the appended claims.

This application is a continuation-'in-part of application Serial No. 206,295, filed January 16, 1951, now abandoned.

I claim:

1. A process for forming a nonsoap detergent bar which comprises mixing from about 11% to about 32% of a water-soluble alkali metal soap of an aliphatic higher fatty acid and a normally solid synthetic organic nonsoap detergent selected from the group consisting of anionic and nonionic synthetic organic nonsoap detergents with an aliphatic carboxylic acid having from about twelve to about twenty-five carbon atoms in an amount to plasticize the detergent at plodding temperature, and adjusting the moisture content of the resulting mixture not to exceed 5% by weight, bringing the mixture to a plodding temperature within the range of to 200 P. so as to render it plastic and workable without liquefying it, and plodding the mixture in this plastic and workable condition to bar form.

2. A process in accordance with claim 1 which includes extruding the compacted mass through a die to form a solid bar.

3. A process in accordance with claim 1 in which the fatty acid is stearic acid.

4. A process in accordance with claim 1 in which the fatty acid is the mixture of fatty acids derived from coconut oil.

5. A process in accordance with claim 1 in which the mixture also includes a normally solid ester of a high molecular weight aliphatic carboxylic acid and a polyhydric alcohol, said ester being present in an amount up to one half of the amount of the aliphatic carboxylic acid component of the nonsoap detergent bar.

6. A process in accordance with claim 1 in which the organic detergent is an alkyl aryl sulfonate.

7. A process in accordance with claim 1 in which the organic detergent is a lauryl oxyethane amide sulfoacetate.

8. A process in accordance with claim 1 in which the mixture includes an alkyl aryl sulfonate as a supplemental organic detergent.

9. A process for forming a nonsoap detergent bar which comprises mixing from about 11% to about 32% of a water-soluble alkali metal soap of an aliphatic higher fatty acid and a normally solid synthetic organic nonsoap detergent of the formula:

wherein R is an aliphatic hydrocarbon radical having from seven to seventeen carbon atoms and M is a salt-forming cation, with an aliphatic carboxylic acid having from about twelve to about twenty-five carbon atoms in an amount to plasticize the detergent at plodding temperatures, and adjusting the moisture content of the resulting mixture not to exceed 5% by weight, bringing the mixture to a plodding temperature Within the range of 100 to 200 F. so as to render it plastic and workable without liquefying it, and plodding the mixture in this plastic and workable condition to bar form.

References Cited in the file of this patent UNITED STATES PATENTS 2,175,285 Duncan Oct. 10, 1939 2,356,903 WVoocl Aug. 29, 1944 2,407,647 Bodman Sept. 17, 1946 2,462,758 Malkemus Feb. 22, 1949 2,678,921 Turck May 18, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,868,731 January 13, 1959 Lloyd F. Henderson et al.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that thesaid Letters .Patent should read as corrected below.

Column 1, line 51, for "non-soap" read nonsoap column 3, line 70,

after "acid" insert considerably Signed and sealed this 12th day of May 1959.

(SEAL) I Attest:

KARL H, AXLINE ROBERT C. WATSON Attesting Oificer v Commissioner of Patents

Claims (1)

1. A PROCESS FOR FORMING A NONSOAP DETERGENT BAR WHICH COMPRISES MIXING FROM ABOUT 11% TO ABOUT 32% OF A WATER-SOLUBLE ALKALI METAL SOAP OF AN ALIPHATIC HIGHER FATTY ACID AND A NORMALLY SOLID SYNTHETIC ORGANIC NONSOAP DETERGENT SELECTED FROM THE GROUP CONSISTING OF ANIONIC AND NONIONIC SYNTHETIC ORGANIC NONSOAP DETERGENTS WITH AN ALIPHATIC CARBOXYLIC ACID HAVING FROM ABOUT TWELVE TO ABOUT TWENTY-FIVE CARBON ATOMS IN AN AMOUNT TO PLASTICIZE THE DETERGENT AT PLODDING TEMPERATURE, AND ADJUSTING THE MOISTURE CONTENT OF THE RESULTING MIXTURE NOT TO EXCEED 5% BY WEIGHT, BRINGING THE MIXTURE TO A PLODDING TEMPERATURE WITHIN THE RANGE OF 100 TO 200* F. SO AS TO RENDER IT PLASTIC AND WORKABLE WITHOUT LIQUEFYING IT, AND PLODDING THE MIXTURE IN THIS PLASTIC AND WORKABLE CONDITION TO BAR FORM.