AU8929291A

AU8929291A - Syndet bar with long chain alkyl sulfates for improved processability and bar characteristics

Info

Publication number: AU8929291A
Application number: AU89292/91A
Authority: AU
Inventors: Theresa Anne Bakken; Wayne Ellis Eccard; Lawrence Allen Gilbert; James Robert Schwartz
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1990-10-30
Filing date: 1991-10-21
Publication date: 1992-05-26
Also published as: JPH06504764A; CA2095039A1; EG19712A; IE913772A1; NZ240376A; PT99367A; ATE131865T1; MX9101830A; FI931933A; DE69115714D1; NO931543D0; CN1062164A; FI931933A0; BR9107038A; MA22329A1; WO1992007931A1; EP0555342A1; TR27389A; MY131207A; EP0555342B1

Abstract

This invention is an improved mild personal cleansing syndet bar comprising: long chain alkyl sulfate having essentially saturated C15-C22, preferably C16-C18, alkyl chains, more preferably cetearyl sulfate, combined with a selected plasticizer.

Description

SYNDET BAR WITH LONG CHAIN ALKYL SULFATES FOR IMPROVED PROCESSABILITY AND BAR CHARACTERISTICS

TECHNICAL FIELD This invention relates to cleansing bars based on synthetic surfactants and to processes of making them.

BACKGROUND OF THE INVENTION

Synthetic surfactant-based personal cleansing bars have attracted much interest recently because they tend to be milder to the skin than soap-based products. This mildness, however, comes with negatives to both the manufacturer and the consumer. The manufacturer experiences difficult processability due to the sticky nature of such products, as well as high raw material costs. The consumer experiences the negative performance prop- erties of smear, bar softness and consequently high wear rates.

There is a strong need to develop a mild bar product that is easily processable on conventional equipment while having accept¬ able in-use characteristics.

OBJECTS OF THE INVENTION This invention relates to skin cleansing syndet bar compo¬ sitions which provide improved processability and still maintain consumer acceptable bar quality. Therefore, one object of this invention is to provide a composition which exhibits improved processability. SUMMARY OF THE INVENTION

This invention is an improved mild personal cleansing syndet bar comprising: at least about 18% by weight long chain alkyl sulfate having essentially saturated Ci5~C22» preferably. C16-C18, alkyl chains, preferably cetearyl sulfate, combined with a selected plasticizer preferably selected from paraffin, fatty acids, and polyethylene glycols, and mixtures thereof. DETAILED DESCRIPTION OF THE INVENTION To develop a mild synthetic surfactant-based bar without the processability and performance negatives outlined above, it is advantageous to think of the bar as two separate components: the matrix and the actives. The matrix provides the physical charac¬ teristics (processability and bar messiness) while the actives provide lathering and mild properties. The matrix, if not chosen correctly, can impede lather generation, cause poor bar feel, enhance wear rate beyond an acceptable level, and/or reduce product mildness. Likewise, the actives must be chosen so as to provide acceptable levels of lathering without negatively impact¬ ing mildness, a common tradeoff in formulations.

It will be appreciated that the development of an appropriate matrix is a delicate balancing act between plasticity and brittle- ness while not compromising lather performance. Typical matrix materials such as triglycerides, fatty alcohols, monoglycerides, etc., tend to form a sufficiently plastic matrix but also tend to depress lather potential. Other commonly used matrix materials such as salts, sugars, polysaccharides, etc., tend to make an overly brittle and water-soluble matrix that induces poor bar messiness performance.

Disclosed is a syndet bar comprising: (1) from about 18% to about 55%, preferably from about 20% to about 45%, of Ci5-C22_> preferably Ci6~Ci8, essentially saturated long alkyl (chain) sulfates; (2) from about 10% to about 50%, preferably from about 15% to about 40% plasticizer; (3) from about 10% to about 45%, preferably from about 15% to about 40%, high lathering, mild surfactants; (4) from 0% to about 20%, preferably from 5% to about 15%, sodium soap; and (5) from about 2% to about 10%, preferably from about 3% to about 8%, water.

The long chain alkyl sulfates, as defined herein, comprise said long chain alkyl chains at a level of at least about 90%, preferably about 93%, and more preferably about 97%. The long chain alkyl sulfates are derived from corresponding saturated straight chain alcohols. The preferred alkyl sulfate has a ratio of Ci6-Ci8 in the range of from about 100% Cχ6 to about 100% Ciβ by weight. A commercially available C16-C18 alkyl sulfate is SIPON* EC-Ill (formerly SIPEX* EC-Ill), sodium cetearyl sulfate, which is approximately 60% Cχ6 and 36% Ciβ- SIPON* EC-Ill is sold by Alcolac Company, Baltimore, MD 21226. Another source is Henkel Corp., Ambler, PA 19002. Henkel's sodium cetearyl sulfate, LANETTE E, is an estimated 50-50% Ci6-Ci8 alkyl sulfate sold as an emulsifier.

The terms "synthetic bar," also "syndet bar," as used herein mean that the bar has more synthetic surfactant than soap unless otherwise specified. The term "AS syndet bar" means a syndet bar containing alkyl sulfate surfactant. The term "long chain" means C15 and C22» and mixtures thereof.

The percentages, ratios, and parts herein are on a total composition weight basis, unless otherwise specified. All levels and ranges herein are approximations unless otherwise specified. It is noted that surfactant mildness can be measured by a skin barrier destruction test which is used to assess the irri- tancy potential of surfactants. In this test the milder the surfactant, the lesser the skin barrier is destroyed. Skin barrier destruction is measured by the relative amount of radio- labeled water ( H-H20) which passes from the test solution through the skin epidermis into the physiological buffer contained in the diffusate chamber. This test is described by T.J. Franz in the J. Invest. Dermatol.. 1975, 64, pp. 190-195; and in U.S. Pat. No. 4,673,525, Small et al., issued June 16, 1987, incorporated herein _Dy reference, and which disclose a mild alkyl glyceryl ether sulfonate (AGS) surfactant based synbar comprising a "standard" alkyl glyceryl ether sulfonate mixture. Barrier destruction testing surprisingly shows that the long chain alkyl sulfates are milder than standard AGS. The long chain alkyl sulfate comprises 18-55% by weight of the bars of this invention. Other syndet bar ingredients are selected from: other surfactants, polymeric skin feel aids, moist¬ urizers, plasticizers, fillers, etc. A preferred syndet bar comprises: about 20-45% of cetearyl sulfate; 5-15% soap; and about 1-35%, preferably about 5-30%, moisturizer; 10-50% plasticizers; and 2-10%, preferably 3-8%, water. To insure mildness and bar firmness, the synthetic detergent surfactant system in the bars should contain the long chain alkyl sulfate.

Other detergent surfactants can be used; particularly from about 10% to about 50%, preferably from about 15% to about 40%, of lather enhancing detergent co-surfactant, e.g., mild ones, e.g., sodium lauroyl sarcosinate, alkylglycerylether sulfonate, and sulfonated fatty acids. Numerous examples of other surfactants are disclosed in the patents incorporated herein by reference. They include limited amounts of other alkyl sulfates, anionic acyl sarcosinates, methyl acyl taurates, N-acyl gluta ates, acyl isethionates, alkyl sulfosuccinates, alkyl phosphate esters, ethoxylated alkyl phosphate esters, trideceth sulfates, protein condensates, mixtures of ethoxylated alkyl sulfates and alkyl amine oxides, betaines, sultaines, and mixtures thereof. Included in the surfactants are the alkyl ether sulfates with 1 to 12 ethoxy groups, especially ammonium and sodium lauryl ether sul¬ fates. Alkyl chains for these other surfactants are Cs-C22_> preferably Cin-Cis. The acyl esters of isethionic acid salts, with esters of Ciδ-Cis acyl isethionates and no more than 25% or lower Ci4 acyl groups are also useful. Preferred is stearoyl isethioniate with C143%; Ciβ 50%; and Cis 47%. Alkyl glycosides and methyl glucose esters are preferred mild nonionics which may be mixed with other mild anionic or amphoteric surfactants in the compositions of this invention. The bars of this invention can have up to about 10% of shorter chain or traditional (coconut) alkyl sulfates and still maintain the mildness requirement of the bar.

A second essential material of the present invention is a plastic binder, also referred to herein as a plasticizer. The syndet bar of this invention also comprises from about 10% to about 50%, preferably from about 15% to about 40%, plasticizer. The plasticizer can be chosen from a group, but not limited to, paraffin, fatty acid, fatty alcohols, polyethylene glycols. The above-mentioned nonionic surfactants, e.g., tallow alcohol ethoxy- lates (TAE), e.g., TAEso* TAEs, etc., are also good plasticizers. Other plasticizers (binders) are identified in the published literature such as J. Amer. Oil Che . Soc. 1982, 59, 442.

The preferred cation in the AS salt is sodium. However, other cations such as triethanolammonium (TEA), ammonium, and K, etc., are also usable. As used herein the term "cationic polymer" includes naturally and synthetically derived cationic polymers. The abbreviation "CN" means coconut and "T" means tallow herein, unless otherwise specified. Al^"[^""percentages and proportions are by weight, unless otherwise specified.

A preferred synbar contains a mixture of free fatty acid (or polyethylene glycol) and paraffin at a ratio of from 3:1 to 1:1. A preferred AS syndet bar also contains from about 10% to about 35% moisturizer, preferably one selected from glycerin and free fatty acid or mixtures thereof. In this case, the free fatty acid serves the purpose as moisturizing and plasticizer ingredient.

The syndet bar of this invention may comprise 0% to about 5% of a suitably fast hydrating cationic polymer. The polymers have molecular weights of from about 1000 to about 3,000,000.

The cationic polymer (skin conditioning agent) is selected from the group consisting of: (I) cationic polysaccharides; (II) cationic copolymers of saccharides and synthetic cationic monomers, and (III) synthetic polymers selected from the group consisting of:

(A) cationic polyakylene imines (B) cationic ethoxy polyalkylene imines, and

(C) cationic poly[N-[-3-(dimethylammonio)propyl]-N'-[3- (ethyleneoxyethylene dimethylammonio)propyl]urea dichloride]. Specific examples of members of the cationic polysaccaride class include the cationic hydroxyethyl cellulose JR 400 made by Union Carbide Corporation; the cationic starches Stalok^® 100, 200, 300 and 400 made by Staley, Inc.; the cationic galactomannans based on guar gum of the Galactasol 800 series by Henkel, Inc. and the Jaguar Series by Celanese Corporation. Examples of members of the class of copolymers of saccharides and synthetic cationic monomers include those composed of cel¬ lulose derivatives (e.g. hydroxyethyl cellulose) and N,N-di- all l,N-N-dialkyl ammonium chloride available from National Starch Corporation under the trade name Celquat.

The cationic synthetic polymers useful in the present in¬ vention are cationic polyalkylene imines, ethoxypolyalklene imines, and poly[N-[-3-(dimethylammonio)propyl]-N'-[3-(ethylene- oxyethylene dimethylammonio)propyl]urea dichloride] the latter of which is available from Miranol Chemical Company, Inc. under the trademark of Miranol A-15, CAS Reg. No. 68555-36-2.

Preferred cationic polymeric skin conditioning agents of the present invention are those cationic polysaccharides of the cationic guar gum class with molecular weights of 1,000 to 3,000,000. More preferred molecular weights are from 2,500 to 350,000. These polymers have a polysaccharide backbone comprised of galacto annan units and a degree of cationic substitution ranging from about 0.04 per anhydroglucose unit to about 0.80 per anhydroglucose unit with the substituent cationic group being the adduct of 2,3-epoxypropyltrimethyl ammonium chloride to the natural polysaccharide backbone. Examples are JAGUAR C-14-S, C-15 and C-17 sold by Celanese Corporation. In order to achieve the benefits described in this invention, the polymer must have characteristics, either structural or physical which allow it to be suitably and fully hydrated and subsequently well incorporated into the soap matrix.

Other ingredients of the present invention are selected for the various applications. E.g., perfumes can be used in formu¬ lating the skin cleansing products, generally at a level of from about 0.1% to about 1.5% of the composition. Alcohols, hydro- tropes, colorants, and fillers such as talc, clay, calcium carbo¬ nate and dextrin can also be used. Cetearyl alcohol is a mixture of cetyl and stearyl alcohols. Preservatives, e.g., sodium ethylenediaminetetraacetate (EDTA), generally at a level of less than 1% of the composition, can be incorporated in the cleansing products to prevent color and odor degradation. Antibacterials can also be incorporated, usually at levels up to 1.5%. The following patents disclose or refer to such ingredients and formulations which can be used in the soap/synbars of this inven¬ tion, and are incorporated herein by reference:

The syndet bars of this invention have a pH of from 4 to 9 in a 1% aqueous solution. The preferred pH is 5 to 8, more prefer- ably about 7.

Laboratory Assessment of Bar The following test procedures are used to evaluate the critical bar performance attributes of mildness and bar processa¬ bility. Rolling Cylinder Adhesion Test (RCAT1 Methodology

The rolling cylinder adhesion test (RCAT) is designed to simulate the adhesion of the processed synbar formulation to the surfaces of the processing equipment (drying/flaking/plodding/- milling/stamping). It has been shown to correlate with stickiness of products during processing. This stickiness is inversely related to overall bar processability. The synbar of this inven¬ tion has a Relative RCAT (Rolling Cylinder Adhesion Test) Value of less than 1, preferably less than 0.9, and more preferably less than 0.8. A Relative RCAT Value of 1 is assigned to a comparable bar made without the processing aid.

The equipment used for this test is the following. An inclined plane (15*) with raised edges is used as the base for the rolling cylinder. The cylinder itself is made from plexiglass tubing of 4" outer diameter and 11-7/8" overall length; it weighs 735.2 grams.

All evaluations are conducted in a constant temperature/- humidity environment at 80^βF (26^*C) and 15% relative humidity. The synbar product to be tested is grated into small pieces (about 2 mm in length). About 20 grams of the grated product are spread evenly over the surface of the inclined plane (which is covered with Kraft freezer paper). The preweighed cylinder is then placed at the head of the inclined plane and allowed to roll freely over the material until it reaches the end of the run. The cylinder is reweighed, the difference being the weight of material adhering to it. The higher the amount of material adhering to the cylinder, the stickier the product and the more difficult to process. The data is expressed as a percentage of material stuck to the cyl¬ inder (RCAT %) relative to the amount of material available (20 grams).

In Table 1 below, syndet bar Examples 1-46 (described in more detail below in the Examples section of Table 5) are tested for stickiness using RCAT. Comparative Example 1 is a state-of-the- art syndet bar similar to the exemplified bars of Small et al., supra.

TABLE 1 Rolling Cylinder Adh ickinessl Test (RCAT1 Values

TABLE 1 (Continued) Rol l ing C l inder he o S k T C T Va

The RCAT data is a measure of processability in that it correlates very well with stickiness during processing. Compa¬ rative Example 1 is difficult to process because the material adheres to cooling, plodding and stamping equipment during manu¬ facture. All formulas which have a relative RCAT value of less than 1.0, therefore, are easier to process. Of Examples 3-46, for which data are available, all have lower RCAT values and improved processability. The improved processability of these formulas is a direct result of the decreased hygroscopicity of these formulas. Hygroscopicitv Test (Processability) Hygroscopicity is the tendency for a product to take up water under equilibrium conditions. It is a causative factor in the stickiness of materials. The higher the hygroscopicity, the stickier and more difficult to process a material tends to be.

Hygroscopicity is measured by shaving approximately one gram of a bar product and knowing the initial weight and moisture accurately. The shaved product is placed in a constant tempera¬ ture (80^*F), constant humidity (80% R.H.) environment. The total weight of the sample is taken hourly until no further weight is gained. The difference between TFTe initial and final weights is the increase in moisture content of the sample; this value, when combined with the initial moisture, is the hygroscopicity.

In Table 2, the Examples correspond to those shown in Table 1 and are described in detail in Table 5 hereinbelow. The experimental syndet bar Examples all have improved hygroscopicity over the standard bar Example 1.

TABLE Z Hygroscopicity Values

This test was performed according to the procedure described in U.S. Pat. No. 4,812,253, Small et al., issued Mar. 14, 1989, said patent incorporated herein by reference. Frequently, materials which tend to improve processability also tend to have other negatives, particularly in terms of product mildness. Referring to Table 3, using the barrier destruction method to assess product mildness, individual raw materials sodium cetearyl sulfate is shown to be surprisingly more mild than the ultra mild sodium cocoglycerylether sulfonate, as well as a shorter chained AS, sodium dodecyl sulfate. The lower the number in Table 3 the milder the product.

TABLE 3 mg 3-H θ Transported Water 0.137

Sodium Cetearyl Sulfate 0.302 Sodium Cocoglycerylether Sulfonate 0.458 Sodium Dodecyl Sulfate 1.289

Sodium Laurate 1.805

A Method of Making Svndet Bars Crutching

1. Add melted sodium cetearyl sulfate to the crutcher.

2. Add predetermined quantity of Hamposyl L-30 solution to the crucher mix.

3. Add the predetermined quantity of AGS paste to the water in the crutcher. The AGS paste can be at ambient temperature or preheated to 150'F (65'C).

4. Turn on the agitator and recirculation pump and maintain temperature in crutcher at 130-150^βF (54-65^βC) by adjusting steam and water valves. 5. Allow contents in crutcher mix to return to 130-150°F

(54-65'C) prior to adding predetermined quantity of stearic acid. 6. Add to heated crutcher mix predetermined quantity of soap or NaOH to form in-situ soap. 7. Allow the contents in the crutcher to mix and/or react for about 15 minutes while maintaining the temperature at 130-150'F (54-65'C).

8. Add to heated crutcher mix the predetermined quantity of acyl isethionate. Allow contents in crutcher to mix for about 20 minutes while maintaining temperature at

130-150^βF (54-65'C).

9. Add sodium chloride plasticizer and titanium dioxide to the heated crutcher mix. 10. Add 1auric and/or coconut fatty acids to crutcher mix and allow contents of crutcher to mix for about 15 minutes while maintaining temperature at 130-150'F (54-65'C).

Drying

The crutcher mix is dried and cooled using a combination flash chamber and chill roll or chill belt. The crutcher mix is first heated to approximately 300'F (149'C) by a heat exchanger and then flash dried in a chamber above the chill roll or chill belt. From the flash chamber the hot, dried mix is extruded onto the chill roll or chill belt. The chill belt or chill roll provides a uniform, thin, cool (85-95'F, 29-35'C) product in flake or chip form. Typical moisture for the flake is 1-10%, preferably about 2-4.5%. The ways to regulate the moisture, in the order of preference, are (1) increasing or decreasing steam pressure on the heat exchanger; (2) increasing or decreasing crutcher mix rate to the heat exchanger; and (3) increasing or decreasing crutcher mix temperature to the heat exchanger. Amalgamating

The flakes are weighed and mixed in a batch amalgamator to obtain uniform flake size. Preweighed perfume is added to the flakes and mixed in the amalgamator to obtain the desired finished product perfume level. The perfumed flakes are transferred to the mix hopper or directly to the plodder. Milling (Optional)

The 3-roll soap mills are set up with the first roll at 120°F (49'C) and the other two mills at about 44'F (7'C). The material is passed through the mills several times to provide a homogeneous mixture of perfume and dried flakes. Plodding and Stamping

The plodder is set up with the barrel temperature at about 125'F (52'C) and the nose temperature at 120'F (49'C). The ideal plodder is a dual stage plodder that allows use of a vacuum of about 15-25 inches of Hg. The plugs should be cut in 5" sections and stamped with a cold die block using die liquor such as alcohol, if appropriate. EXAMPLES

The following examples are illustrative and are not intended to limit the scope of the invention(s). The detailed methods of making milled bars is well known. All levels and ranges, te - peratures, results etc., used herein are approximations unless otherwise specified.

The formulations illustrated in Examples 1 and 2 are compara¬ tive examles included for illustration. Example 1 is an AGS- based, state-of-the-art product, while Example 2 is an estimated formulation of Colgate-Palmolive VEL^® syndet bar with <15.0% sodium cetearyl sulfate.

Examples 3-49 contain from 26-46% sodium cetearyl sulfate and represent the broad range of formulations acceptable within the matrix of this invention. The sodium cetearyl sulfate contains primary Ci6-Ci8 alkyl chains.

COMPARATIVE EXAMPLE 1

Comparative Example 1 is the control bar for assessing processability of the bars of this invention. See Table 4. Using this comparative example, it will be shown that bars described below have improved processability without sacrificing mildness or other bar performance properties.

COMPARATIVE EXAMPLE 2 Comparative Example 2 is a standard syndet bar made by the Colgate-Palmolive Co. under the name Vel®. This product contains an estimated 10% to 15% sodium cetearyl sulfate, significantly less than the levels required in the present invention. Addi¬ tionally, the Vel bar has unacceptable bar use properties such as smear and lather volume.

Examples 3-49 are all based on a matrix composed of sodium cetearyl sulfate (26-46%) and stearic acid (0-20%). To this matrix are added various lathering surfactants such as sodium lauroyl sarcosinate (0-20%); sodium cocoglycerylether sulfonate (0_r35%); sodium cocoyl isethionate (0-17%); and sodium soap (0-15%). Laurie acid (0-20%) along with the stearic acid, are added to ensure product pH less than or equal to 7.5. Processing aids such as plasticizers (paraffin, cottonseed oil and PEG-8000), and fillers, calcium carbonate and dextrins are added (0-15%) to reduce stickiness and improve plodding.

TABLE 5 (Continued)

Ex. 15 Ex. 16 Ex. 17 Ex. 18

In^gredient (Wt.%) (Wt.%) (Wt.%) (Wt.%) Sodium Cetearyl

Sulfate 35.3 35.3 33.5 45.0 Sodium Lauroyl

Sarcosinate 15.0 15.0 14.3 5.0 Sodium Cocoglyceryl- ether Sulfonate 9.0 9.0 8.6 17.5 Sodium Cocoyl Isethionate 9.0 9.0 8.6

Sodium Soap 7.5 7.5 7.1 7.5 Sodium Lauryl

Sulfate - - 5.0 5.0

Stearic Acid 14.0 14.0 13.3 16.0 Laurie Acid 6.0 6.0 5.7 4.0

Water 4.3 4.3 4.0 5.0

Total 100.0 100.0 100.0 100.0 TABLE 5 (Continued)

TABLE 5 (Continued)

TABLE 5

TABLE 5 (Continued)

Examples 33, 43 and 49 are highly preferred syndet bars which are easy to process while still performing well in terms of bar properties.

Claims

- 2! - Claims

1. A personal cleansing syndet bar ccnprising: frcm about 18% to about 55% of essentially saturated long diain C^-C.. alkyl sulfate; frcm 0% to about 20% of soap; and from about 10% to about 50% of a plastic binder selected frcm the group consisting of: paraffin waxes, fatty acids, wherein said plastic binder has a melting point of frcm abcut 23°C to about 110°C; wherein said plastic binder is selected from the group consisting of paraffin, nαniαnic surfactants, fatty acid, fatty alcohols, and polyethylene glycols, and mixtures thereof; and wherein said syndet bar has a pH of frcm abcut 4.0 to about 8.5.

2. A personal cleansing syndet bar according to Claim 1 wherein said plastic binder is selected from the group consisting of: paraffin waxes and fatty acids.

3. The syndet bar of Claim 1 or 2 wherein the level of long εάn alkyl sulfate .is frcm about 20% to about 45% by weight of said bar and said soap is from about 5% to about 15% by weight of said bar; and wherein said plastic binder melting point is frcm about 30°C to about

100°C and wheredLn said long chain is C 1.6-.-C1,8-.

4. The personal cleansing syndet bar of Claim 1 or 2 wherein .said bar primarily ccnprising: .frcm about 15% to about 40% of said plastic binder; and wherein said long chain alkyl sulfate .is present at a level of from about 20% to about 40% and is a saturated long chain alkyl sulfate surfactant saturated alkyl chains of from about 16 to about 18 carlson atoms; and frcm about .15% to about 40% of a mild cosurfactant.

5. The syndet bar of Clam 4 whereύ said mild cosurfactant selected from the group cons.Lst.ing of higher lather.ing sodium lauroyl sarcosinate, alkyl glycerylether sulfonate, sodium cocoyl isethionate, stearσyl isethionate, and mixtures thereof, and frcm about 2.0% to .about 10% water and wherein said syndet bar is a milled bar and has a pH of frcm about 5 to about 8. - 2Z-

6. The syndet bar of Claim 1 car 2 wherein said soap-synthetic .bar contains other .cαπpαneπts selected frcm: moisturizers, colorants, solvents, fillers, other .surfactants, polymeric skin feel and mildness aids, perfumes, and preservatives, and water at a level of frcm abcut 3% to about 8% wherein .said bar contains said C₁₆ and C.„ alkyl chains having a ratio of frcm about 4:1 to abcut 1:4.

7. The syndet bar of Clam 3 wherein said long chain alkyl sulfate is at least 90% C1,6- and C1,8_β.

8. The personal cleansing syndet bar of Claim 4 wherein said mild cosurfactant is selected frcm the group consisting of sodium lauroyl sarcosinate, aH^~γl glycerylether sulfonate, sodium cocoyl isethionate, stearqyl isethionate, and mixtures thereof, and is frcm about 2.0% to abcut 10% water; and where^ said syndet bar is a milled .bar and said pH is from abcut 5 to abcut 8; and wherein said bar contains said C_lg and C,- alkyl chains having a ratio of from abcut 4:1 to about 1:4 and contains from about 15% to -about 40% of a mixture of free fatty acids and paraffin at a ratio of frcm abcut 3:1 to abcut 1:1.

9. The syndet bar of Claim 3 wherein said plastic binder is a mixture of free fatty acid and polyethylene glycol at a ratio of from about 3:1 to about 1:1.