IE45628B1 - Soap bars - Google Patents

Abstract

A toilet soap bar comprising soap, water-soluble hydrolyzed protein having a molecular weight in the range of 600 - 12,000 and water-soluble poly(ethylene oxids) of molecular weight at least 100,000 which has improved characteristics such as hardness, toughness, wet slipperiness, etc. and good resistance to sloughing.

Description

This invention relates to soap bars, particularly. toilet soap bars.

It has now been found that the inclusion of poly (ethylene oxide) of very high molecular weight in a toilet . soap bar containing the hydrolyzed protein significantly improves the characteristics of the bar.

Alkaline toilet soap bars are slippery when wetted, and give a slippery lather. Synthetic detergents do not have this property and, in an effort to overcome this . defect, poly (ethylene oxide) of very high molecular weight (sold in U.S.A. under the trademark Polyox) has been included in toilet soap bars composed predominantly of such detergents. The use of polyethylene oxide of high molecular weight for that purpose is described in . chapter 9 of the book Water Soluble Resins by Robert L. Davidson and Marshall Sittig published 1962 by Reinhold, New York, particularly at pages 197-19S.

This same book also describes (at page 198) the use of the Polyox in face creams, hand creams, shaving preparations . and shampoos, stating In creams and lotions based on soap, such as vanishing creams, Polyox resin depresses foam and thereby contributes to ease of manufacture and fill. The resin also reduces the tendency to soap-up during application.

. In accordance with the invention a soap bar comprises soap, solubilized hydrolyzed protein and .

PDly (ethylene oxide) having an average molecular weight of at least 100,000. ' The invention makes is possible to provide soap bars . which are hard, tough and shiny, when wetted have a degree of slipperiness pleasant to the user, give a 2. 4362S laxher which is creamy, pleasantly silky and effective, have good resistance to sloughing in use despite a high moisture pickup, are long lasting and are flexible and tough even after much of the bar has been used up, . provide a beneficial effect on the hands (e.g. reduce chapping and flaking, and moisturize the skin, particularly dry skin).

The soap may constitute at least 60%, preferably more than 70% of the moisture-free weight of the bars of . the present, invention. These and all other percentages and proportions given herein are by weight. The soap may be of a conventional type consisting predominantly of 12 to 18 carbon atom molecules and may be produced by the saponification of fatty materials suitable for . use in soap making, suitable fatty materials comprising, for example, fats, oils and waxes of animal, vegetable or marine origin and fatty acids derived therefrom, or of synthetic origin. More specifically, the fatty acids may be of mixed character such as are derived from . natural or hydrogenated tallow, cottonseed oil, coconut oil, palm oil, palm kernel oil, babassu nut oil, grease, fish oils, and fatty acids derived therefrom by hydrolysis or saponification, or they may be pure materials such as lauric, myristic, palmitic, stearic and oleic . acids. It is generally preferred to use the sodium salts of the mixed fatty acids derived from tallow and coco (coconut oil) and mixtures thereof. A desirable blend has a weight ratio of sodium coco soap to sodium tallow 'soap in the range from 50:50 to 10:90, a ratio below . 30:70, e.g. a range from 25:75 to 17:83, being 3. . 43638 especially preferred. As is known in the art, the higher coco contents give faster, more copious lather but more irritation, in conventional soaps. It is 4 permissible to use blends of the sodium soaps and the . corresponding potassium soaps (e.g. in mole ratios of sodium:potassium of 90:10 or 75:25).

A particularly preferred hydrolyzed protein is Protein A sold by Croda Inc., New York, N.Y., U.S.A., and is a partially enzymatically hydrolyzed protein . derived from beef collagen and characterized by having a zero Bloom gram gel strength, a 10% weight/weight water solution having a viscosity range of about 16 .to about 25 millipoises (mps), a pH of 5.5 to 6.5, and a hydroxyproline content (mainly chemically combined . hydroxyproline) of about 10% to about 12%, a nitrogen content of about 15% to about 18%, and a total nitrogen as amino nitrogen of about 5% to about .12%, and a molecular weight of about 1,000 to about 3,000,.such as about 2,000. Its ash content is generally low (e.g. . below 10%). Other hydrolyzed proteins which may be used include hydrolysis.products comprising proteoses, peptones and/or polypeptides,, typically having a molecular v/eight in the range.from 600 to 12,000, preferably below 5,000, and including moieties of a . plurality of amino acids. These hydrolysis products may be formed by partial enzymatic hydrolysis, Such as by the action of trypsin, erepsin or pancreatic enzymes on protein material (e.g. at about 35 to 50°C for about 12 to about 48 hours). The partially degraded protein . may also be a product obtained by partial hydrolysis 4. of protein by heat and/or alkali. Proteins partially degraded by heat may be prepared, for instance, by heating proteinaceous material such as bones, feet or skin of pork or beef which has been reduced to small pieces · and immersed in water, by autoclaving at about 2.8 I Q • to about 3.5 kg/cm of saturated steam (i.e. at from 141.5 ' j to 147°S°c) for about two hours; three phases including fat, the desired aqueous phase and a residue may thus be obtained; the aqueous phase, which may contain from about . 8% to about 10% solids, may be concentrated in vacuo to about 50% to about 60% solids at 60-71°C to obtain a solubilized collagen, a heat degraded protein, which may be employed in the soap of this invention. Typical proteins which may be partially hydrolyzed for use in · soaps of this invention include casein, gelatin, collagen, albumin, zein, gliadin, keratin, fibroin, globulin and glutenin., Typical commercial partially enzymatically hydrolyzed proteins include Bacto-Proteose (sold by Difco Laboratories, Detroit, Mich., U.S.A.), proteose20. peptone, casein-peptone, gelatin-peptone, Bacto-Peptone (sold by Difco Laboratories), vegetable peptones, such as soybeams peptone, Proto-Peptone (sold by Wilson Co., U.S.Α., the peptone enzymatically derived from solubilized collagen using ground frozen pancreatic enzymes . 25. having a pH of 8, digestion being at about 49°C for about 12 to about 48 hours, the solubilized collagen being derived by heating bones, feet or skin of pork or beef). The preferred proteins are solubilized beef collagen and solubilized pork collagen which may be . prepared as described and are generally characterized · 3 6 2 8 by a gel strength of about zero Bloom grams.

The partially hydrolyzed protein may have a relatively broad spectrum of molecular weights and may contain some (usually small amounts of) almost . completely degraded poly-peptides, such as dipeptides and tripeptides and even some amino acids, as a result of the degradation process. If desired, these may be removed by dialysis, e.g. by placing the partially degraded protein in a cellophane bag which . is then closed at both ends and is lowered into a tank into which deionized water continuously enters and from which it continuously leaves; products such as the tripeptides, dipeptides and aminoacids pass out through the cellophane by dialysis to mix with the deionized . water and leave the partially degraded protein. When employed, the dialysis procedure has the additional advantage of removing the odours of the more completely hydrolyzed material.

The proportion of protein ingredient .in the . soap bar is generally in the range from 0.1% to 10%.

Amounts in the range.from 1% to 5% are preferred, a level of about 3% being especially preferred.' For the preferred protein material the 1% to 5% range provides a hydroxyproline content of about 0.1% to about 0.5%, . preferably about 0,3%. The protein ingredient in combination with the other ingredients assists in improving the overall properties of the bar, including its skinmoisturizing effect, particularly on dry skin, antichapping and anti-flaking properties.

Examples of suitable poly (ethylene oxide) compounds are those sold by Union Carbide Company, U.S.A., under the trademark Polyox. These polymers are nonionio and extremely . . soluble in water and their molecular weights range from about 100,000 to about 5,000,000 or more. It is preferred to employ polymers having average molecular weights below 1,000,000, more preferably not above 600,000 such as about 300,000 to about 400,000. The . proportion of high molecular weight polymer of ethylene oxide in the soap bar is generally below 10% and is preferably more than 0.5%, e.g. at least 1% and less than 5%, more preferably below 4%. For the material having an average molecular weight of about 300,000 . a proportion in 'the neighbourhood of 2% has given excellent results. This 300,000 molecular weight material (sold as Polyox WSR N-750) has a viscosity at 25°C for a 2% aqueous solution of about 40 centipoises (Brookfield Spindle No. 1 at 10 rpm); for a 5% solution the viscosity . is about 600 to about 1,000 centipoise. Use of, say, 2% of extremely high molecular weight poly (ethylene oxide), e.g. of 4,000,000 average molecular weight, causes the lather to be pituitous, which is less desirable.

According to the manufacturer the Polyox materials . typically have a-pH of about 10 (e.g. in 5% solution).

Soap typically has a pH in 1% aqueous solution of about 10 (e.g. 10.2).

The poly (ethylene oxide) is generally supplied as a powder and typically has the following particle . size distribution when a sample Thereof is screened 7, „ 45638 through a series of sieves, expressed as weight percent retained on the indicated Sieve No. screen (U.S. Sieve Series): No. 20-5.2$; No. 40-31.2%; No. 60-20.7%; No. 100-16.7% and through No. 100-balance. It is · often preferable to use a finer particle size poly (ethylene oxide)jhaving the following distribution as measured above: ko. 20-0.3%; No. 40-13%; No. 60-13%; No. 100-13.9% and through No. 100-balance.

The bars may also contain a synthetic surfactant 10. of high foaming characteristics in hard water,. such as alkali metal salts of organic sulphuric reaction products having in their molecular structure an alkyl radical of from 8 to 22 carbon atoms, e.g. alkyl benzene sulphonates, coconut oil fatty acid monoglyceride sul15. phonates and sulphates, and alkali metal fatty acid (C-|Q-C^g) isethionates. A particularly preferred ester is sodium coco isethionate sold as Igepon AC-78 by the General Aniline and Film Corporation. U.S.A. The proportion of synthetic surfactant is generally in the . range from 0,5% to 5%, and preferably from 1% to 3%, e.g. about.2%. Preferably the weight ratio of synthetic surfactant to high molecular weight poly (ethylene oxide) is in the range from 2:1 to 1:2, such as about 1:1.

In addition to the components mentioned above, . the soap bars may contain other additives in small proportions, including those usually found in soap bars, such as fillers, perfumes, dyes, fungicides, humectants (e.g. 0.2% to 3% of glycerine) and bactericides. Additionally, if desired, super-fatting agent may be . included in the bars to impart special effects on the 8. £3628 skin. It is found that acetylated lanolin (such as Modulan sold by American Cholesterol, U.S. A.; see U.S. Patent No. 2,725,334) gives especially good results.

Other superfatting agents are hydroxylated lanolin, . (e.g. OH Lan sold by American Cholesterol), higher (C10-C20) fatty acids such as stearic acid or coconut oil fatty acid, higher (Ο^θ-Ο^,θ) fatty alcohols and petrolatum. Amounts of superfatting agents less than 10% total are generally employed, preferably from . 1% to 5%, e.g. 2% to 3%.

The invention is particularly suitable for the making of milled and plodded toilet soap bars. Bars of this type are well known in the art; see for instance the description thereof in U.S. Patent 3,179,596. Also see . “Encyclopedia of Chemical Technology, Volume 12, edited by Kirk and Othmer, pages 573-598 and Industrial Oil and Fat Products, Alton E. Bailey, Second Edition, 1951, pages 365-386 and 840-865. Thus one may take a kettle soap, form it into dried chips (as described in . the foregoing references) and blend it with the various ingredients before milling and plodding.

The moisture contents of the soap bars of this invention are such as to provide a solid, non-tacky bar, preferably they are well below 30%. For a milled, · plodded bar they are generally less than 20%, preferably in the range from 10% to 17%, such as about 13%.

Milled, plodded soaps typically are made up of fine crystals of hydrated fatty acid salt. The high molecular weight poly (ethylene oxide) appears to have . an affinity for the moisture in the soap but the 9. physical state of the material in relation to the soap . crystals is not presently known. , Toilet soap bars generally range in size from the relatively small hotel size (weighing from about . 20 to about 30 grams) through the regular size (about 100 grams) and the bath size (about 150 g) to the ι extra large size (about 200 g). The soap bars of this invention may be of such sizes, particularly in the range from 100 to 200 grams. The soap may also be aerated, . in a manner well known to the art, to give lower density (floating) soaps, such as those having a specific gravity of about 0.8.

The ingredients are preferably brought together in a conventional soap amalgamator by mixing soap chips . with the poly (ethylene oxide) powder while the surfaces of the soap chips are in powder-adherent condition with respect to the polyethylene oxide powder to produce soap chips having poly (ethylene oxide) bonded thereto, then adding other ingredients of the soap bar and mixing . the other ingredients with the bonded chips, then forming the resulting mixture into a soap bar. Two preferred procedures are (a) adding the powdered high ; molecular weight poly (ethylene oxide) to soap chips having a moisture content such that the powder adhere . thereto (e.g. at least 11% water) and mixing, before adding the other solid ingredients, and (b) adding the powdered high molecular weight poly (ethylene oxide) to soap chips having a lower moisture content, mixing, and then adding some water in a finely dispersed state (e.g. . to bring the water content, based on soap, to a level' . d a 6 2 8 sufficient to provide powder adhesion) before adding the other solid ingredients. This procedure substantially avoids the formation of visible specks comprising poly (ethylene oxide). The reason for this is not . understood,. but it may be that the particles of high molecular weight poly (ethylene oxide) (whose moisture sorption is below 3% at a relative humidity of 60% at 25°C, according to the manufacturer’s bulletins) takeup sufficient moisture from the higher moisture content , soap chips and become bonded, individually, to the surfaces of the chips so that these particles are thus prevented from agglomerating; if there is not sufficient moisture for this to occur before the subsequent addition of other solid ingredients (particularly powders of low . moisture contents, e.g. below 8% water), the latter may compete for the limited amount of moisture available and loose particles of high molecular weight poly (ethylene oxide) may agglomerate in later stages.

The following Examples illustrate the invention.

. EXAMPLE I A soap bar of the following composition is prepared by adding the ingredients, in the order listed to a conventional soap amalgamator (while the blades thereof are moving) operating at room temperature. Component Weight % Soap chips (17 sodium coco soap/83 sodium tallow soap)1 88.50 50% aqueous solution of stannic chloride (a preservative) 0.15 Poly (ethylene oxide) 2.00 Water 1.00 11. - 43628 Titanium dioxide-powder (substantially 0.60 moisture-free, a pigment) Protein A-powder (containing up to 6% moisture) 3.00 . Sodium coco isethionate-powder (containing 1% to 2% moisture) 2.00 Glycerine 0.50 Aeetylated lanoliin^ 1.00 Perfume 1.25 100.00 . Moisture is about 11.5%; bar moisture 10.5%; measured by weight loss at 105°C.

Poly WSR N-750 in the form of powder, of size such that less than 5% by weight (e.g. 0.3%) is retained on a 20 mesh screen (U.S. Standard) . Modulan-added. in molten state (temperature about 120°P).

When added to the soap chips in the amalgamator, the individual particles of the homopOlymer of ethylene oxide stick to the chips, especially when the water is . then sprinkled onto the moving chips. The other ingredients are then added in the order indicated, while mixing is continued for a total of about 2 minutes. At this time the mixture is not clumped together, but is still flowable, in chip form.

. The blend is then milled on a conventional five-roll soap mill to a thickness of about 0.05 to about 0.1 mm, the resulting milled chips having a temperature of about 34 to about 37°C. The chips are fed directly Into a jacketed soap plodder and extruded to form a . continuous bar (plodder bar). The plodding is con12. 6 2 8 trolled in one run to produce a plodder bar whose core temperature measured directly after extrusion is about 34 to about 38°C; in a second run the temperature is controlled to give a ploddea* bar core temperature of . about 40 to about 43°C. The plodder used is a DoelgerXirsten eight inch double barrel Vacuum Plodder, Schwantes Design. The plodder bars are cut in conventional fashion to give units whose volumes are suitable for a toilet soap bar (e.g. about 140 g for a . bath size bar and about 100 g for a regular size bar) and pressed in conventional metal soap-pressing dies to the final rounded shape of the toilet bar. The units made from the higher temperature plodder bars are more difficult to press, without sticking to the die, but . when the same plodder bar is cooled to about 38°C the pressing is much better.

Examination and use of the bars show1a smooth surface, similar to that of normal soap bars. They are hard,' tough and shiny, have a degree of slipperiness . when wetted which is especially pleasant to the user, give a lather which is creamy, pleasantly silky and effective, have good resistance to sloughing in use despite a high moisture pickup, are long lasting and are flexible and tough even after much of the bar has been . used up, provide.a beneficial effect on the hands (e.g. reduce chapping and flaking, and moisturize the skin particularly’dry skin).

EXAMPLE II Example I is repeated .except that the sodium . coco isethionate is omitted from the formation and the 13. 43628 soap content is correspondingly increased.

EXAMPLE III Example X is repeated except that the acetylated lanolin is omitted from the formulation and the soap . content' is correspondingly Increased.

EXAMPLE IV Example I is repeated, except that the coco and tallow soap ratio is 25/75, the soap chips have a higher moisture content (about 14% moisture), there is . no separate addition of water (and the bar moisture •content is thus about 13%), and higher plodder -temperatures are used so as to produce a bar having a .core temperature of about 50°C. The bar surface is · then cooled (with cool air), and a film of pressing . lubricant (e.g., an aqueous solution containing 16% sodium chloride and 25% glycerol) is directly applied to the pressing dies before each pressing operation. EXAMPLE V · (aj Example I is repeated with the following 20. formulation: Component Weight % Soap chips (25 sodium coco/75 sodium tallow) 89.25 50% aqueous solution of stannic chloride 0.15 25. 50% aqueous solution of citric acid (to react with ahy excess alkali) . 0.25 Poly (ethylene oxide) 2.00 Titanium dioxide 0.06 Protein A 3.00 Sodium coco isethionate 2.00 30. Hydroxylated lanolin 1.00 14.

.J .3 '%> 2 8 (1) Added as Polyox WSR N-750 (b) Example V (a) is repeated except that the Glycerine Perfume 0.50 1.25 400.00 proportion of poly (ethylene oxide) is reduced to 1% and the soap content is raised by 1%. Users prefer the product of Example V (a). (c) Example V (a) is repeated but a second 10. poly (ethylene oxide), 0.5% Polyox WSR-N-3000 (molecular weight 400,000), is also included and the soap content is correspondingly lowered to 88.75%.

EXAMPLE VI Example V is repeated except that the sodium . coco isethionate is omitted (the soap chips being increased to 91.25%) and the polyethylene oxide has an average molecular weight of about 400,000 (Polyox WSR-N-3000).

Claims (15)

1. A soap bar comprising soap, solubilized hydrolyzed protein and poly (ethylene oxide) having an average molecular weight of at least 100,000. 5

2. A soap bar as claimed in Claim 1 wherein the solubilized hydrolyzed protein has a molecular weight in the range from 600 to 12,000.

3. A soap bar as claimed in Claim 1 or Claim 2, wherein the hydrolyzed protein is present in an amount in 10 the range from 0.1% to 10% and the poly (ethylene oxide) is present in an amount in the range from 0.5% to 10%.

4. A soap bar as in Claim 3 wherein the protein is present in an amount in the range from 1% to 5% and the poly (ethylene oxide) is present in an amount in the range from 1% 15 to 4%. '

5. A soap bar as claimed in any of the preceding Claims wherein the hydrolyzed protein is a collagen hydrolysis product.

6. A soap bar as claimed in any of the preceding 20 Claims wherein the poly (ethylene oxide) has an average molecular weight in the range from 100,000 to 1,000,000. - 16 4 5 6 3 8

7. A soap bar as claimed in any of Claims 1 to 5 wherein the poly (ethylene oxide) has an average molecular weight in the range from 300,000 to 500,000.

8. A soap bar as claimed in any of the preceding Claims wherein the protein has a molecular weight in the range from 1,000 to 3,000.

9. A soap bar as claimed in any of the preceding Claims wherein the hydrolyzed protein provides a hydroxyproline content in the range from 0.1% to 0.5% of the soap bar.

10. A soap bar as claimed in any of the preceding claims wherein the soap is present in an amount of at least 50%.

11. A soap bar as claimed in any of the preceding claims comprising a synthetic surfactant present in an amount in the range from 0.5 to 5%.

12. A soap bar as claimed in any of the preceding Claims which also contains a superfatting agent.

13. A soap bar as claimed in Claim 12 wherein the superfatting agent is present in an amount up to 10%.

14. A soap bar as claimed in Claim 12 wherein the poly (ethylene oxide)has a molecular weight in the range from 300,000 to about 400,000, the superfatting agent is acetylated lanolin and is present in an amount in the range from 1% to 5%, and which also contains glycerin in an amount in the range from 0.2% to 3% and sodium coco isethionate in an amount in the range from 1% to 3%.

15. A soap bar substantially as described in any of the Examples.