CA1196866A - Shaving stick - Google Patents

Abstract

Abstract of the Disclosure A novel shaving stick containing as essential ingredients glycerol monooleate, and sodium stearate, in a ratio ranging from about 3/1 to about 5/1 and a method of razor-shaving therewith, the stick overcoming prior art deficiences such as undue softness or hardness, insufficient lubricity and tendencies to liquify or dry out during storage.

Description

This invention relates to shaving sticks, especially shaving sticks which are transparent, resistant to rancidity, provide c~cellent lubricity during shaving and/or rinse readily from razor and skin.
The most widely used method of shaving hair on the skin, e.g~ on legs, underarms and especially men's faces, involves razor-shaving the lathered hair and skin. Lather used preparatory to razor blade shaving performs two principal functions, namely, to soften the hair e.g. the beard, for the purpose of reducing the resistance offered the shaving blade and consequently the distortion of the unsupported hair, and secondly to lubricate the passage of the blade over the surface of the skin to minimize razor drag with its increased tendency to produce skin ;rritation and/or nicksJ cuts and abrasions of the skin.
The use of a shaving stick preparatory to razor blade shaving performs essentially the same two principal functions, and has a further advantage in eliminating the messy step of applying the lather by hand rubbing or patting, or with a shaving brush which must be rinsed and is subject to soap build up, rancidity, and wear. A fully satisfactory shaving stick has however not been readily produced and/or widely commercialized, being subject to such deficiencies, disadvantages and problems as undue softness or hardness, insufficient lubricity, unsatisfactory post rinsibility from razor blade and/or skin, insufficient softening of the hair, tendencies to liquify or to dry out and/or to develop a rancid odor during storage and use, and the like.

It is an object of this invention to provide a shaving stick, and a method of shaving therewith, which will not be subject to one or more of the above deficiencies. Other objects and i. ~
~ ~2-advantages will appear as ~he descript:ion proceeds.
Ihc atta;nment of thc above objects is Made possible by this invention which includes the provision of a preshave assisting composi~ion in stick Eorm comprising, approximately by weight;
I. 25 to 70% of g]ycerol monooleate II. 8 to 25% of sodium stearate, TII~ 0 to 50% of organic humectant, and IV. l to 10% of water, the ratio of I/II ranging from about 3/1 to about 5/1.
According to a preferred embodiment, the above composi-tion contains about 10 to 30 wt. % of propylene glycol as humectant. According to another preferred embodiment, the composition further contains about 1 to lO wt. % of an ethoxameric nonionic surfactant.
This invention also includes the provision of a method comprising razor-shaving hair on the skin in the presence of the above-defined compositions of this invention. Such method typically comprises washing the face ~or other hair-carrying skin portion of the body)~ as with soap and water, rinsing wi~h water, rubbing the shaving stick uniformly on the wet hair and skin to apply a thin film of the stick formulation thereon, and shaving off the hair with a razor (blade). Desirably, the shaved portion of the skin is then again rinsed with water.
The shaving sticks of this invention, whicn may of course be provided in any convenient solid shape, size or surface configuration, have been found to provide excellent lubricity, to be substantially resistant to rancidity~ to have and maintain the desired degree of solidity without softening, liquifying or &~;

~rying out, to sat;sractorily softerl the hair fibers for ease of cutting, to be readily rinsed with water -from ra~or blade and skin, to be desirably transparent or translucent, and/or to leave the shaved portion of the skin with a good feeling.
The essential glycerol monooleate (GMO) provides the excellent lubricity properties attributable to the compositions of this invention. Its use in "neat" form as a shaving aid is however not practical because it is a soft semi-liquid mass at ambient temperatures and is insufficien~ly water soluble, thus making it messy and inconvenient to apply with the hand and difficult to postrinse from razor and skin. U.S. 3,715,942 issued February 13, 1973 to Courtney describes shaving composi-tions which optionally contain GMO as a "preferred liquid nonionic surfactant" but these compositions are liquid and suffer from the same deficiencies as "neat" GMO.
The GMO may be employed in substantially pure formJ
or as commercially available forms containing minor amounts, e.g. less than about 5 w~. % of glycerol dioleates and/or trioleates. A preferred commercially available form is marketed as Atlas* G-3496 (ICI America, Inc.) containing, by weight, 80% of GMO, 10% of propylene glycol, 7% of POE (20) sorbitan monolaurate (sorbitan monolaurate polyoxyethyleneted with 20 moles of ethyleneoxide) and 3% of water. Being a surfactant, the GMO also provides wetting and similar surface active functions, in addition to softening and emolliency.
lhe shaving sticks of this invention typically contain about 20 to about 70, preferably about 30 to 60, wt. % of the GMO.
The essential sodium stearate (soap) component II provides * Trade Mark ','l.~f3~

the requ;red hardening or gelling functioll necessary to form and maintaln the desired solld characteristics of the stlck. It typically constitutes about 8 to 25, preferably about 8 to 20, wt. % of the composition. This soap also provides wetting, rinsing, and similar surface active functions. Other soaps have been found to fail substantially to provide these functions in sufficient degree.
The highly preferred component III organic humectant aids in preventing drying out of the shaving stick, in addition to providing solvent and skin-moisturizing functions. One or a mixture of humectants, well known in the art, may be employed, typically in proportions of about 10 to about 50, preferably about 10 to about 30, wt. %. These humectants are typically polyhydroxycompounds such as glycerol, sorbitol, ethylene, propylene, butylene and hexylene glycols, 1, 1, l-trimethylol propane, 2-methyl-2, 4-pentanediol, neopentyl glycol, poly-ethylene and polypropylene glycols, polyoxyethylenated sorbitol and glycerol (e.g. POE (26) glycerolether), and the like. Propylene glycol is preferred, typically in proportions of about 10 to about 30 wt. %, and combinations thereof with POE glycerol ethers.
Water, in proportions of about 1 to about 10, preferably about 2 to less than 8, wt. % is included in these compositions primarily to help dissolve and/or liquify the sodium stearate for homogeneous admixture with the remaining components of the compositions.

Another preferred component of the shaving stick formulations of this invention is one or a mixture of nonionic surfactants, typically in proportions of about 1 to about 10, preferably about 2 to about 8, wt. %. These surfactants are well known materials and may be broadLy de-fined as water soluble products derivcd from the condensatioll of a plurality of moles of a C2 3 alkylene oxide or equivalellt reacta-nt (hydrophilic in nature) with a reactive hydrogen-conta;ning organic hydrophobic compound whlch may be aliphatic, aromatic, alicyclic or heterocyclic. The length of the hydrophilic polyoxyalkylene chain in the condensation product derived from any particular hydrophobe can be readily adjusted to provide the desired degree of water solubility and balance between hydrophilic and hydrophobic or lipophilic elements (HLB factor). Although propylene oxide may be employed as the alkylene oxide reactant, ethylene oxide is most commonly employed, more effective and preferred herein. These polyoxyethylene-containing condensation products have been referred to as ethoxamers or ethoxameric nonionic surfactants.
The precursor hydrophobe of the nonionic surfac~ant ~ay contain from about 6, preferably from about 8, up to 50 or more carbon atoms and at least one reactive hydrogen-containing moiety as present for example in aliphatic a]cohols, alkyl phenols, carboxylic acids, carboxylic acid amides, sulfonamides, amines, and the like. As a general rule, at least about 4 moles of ethylene oxide should be reacted per mole of hydrophobe, but up to 200 moles of ethylene oxide may be so reacted depending on the hydrophobe, desired water solubility, surface activity, emolliency, plasticity and melting point, and the like. The nonionic surfactant should be liquifiable, e.g. at elevated temperatures up to about 90C, to facilitate processing of the composition into stick form.
Representative operative nonionic surfactants include polyoxyethylene polyoxypropylene block polymers (Pluronics*) and other types as disclosed for example in the portion of U.S. 4,1~10,641 * Trade Mark i6 issued Febru"ry 20, 1979 to Ramachandral-l from line 3 to line ~3 of columll 2. As ~xemplary of specific nol-1ionic surfactants, men~ior is made of dinonyl phenol + l5 e. o. ( 1 mole of dinonyl phenol reacted with 15 moles of ethylene oxide), dodecyl mercaptan ~ 20 E.O., lauramide ~ l8 E.O., stearic acid ~ 20 E.O., tetradecyl amine + 34 E.O., dodecyl sulfonamide + 16 E.O., and myristyl alcohol + 20 E.O. Preferred are condensation products of one mole o-f an alkanol, preferably straight chain and primary, of about 9 to 20, especially lO to 18, carbon atoms with about lO to 40, especially about 15 to 30, moles of ethylene oxide, for example PEC (23) laurylether, and condensation products of one mole of a partial fatty acid ester of a polyhydric alcohol with a similar number of moles of ethylene oxide, for example P~E (20) sorbitan mono-laurate. The nonionic ethoxameric surfactant component provides improved wetting and post-rinsibility functions.
Other optional and conventional additives may be included in small proportions preferably less than about lO wt. % such as perfumes, preservatives, colorants, bacteriostats, antioxidants, proteins, binders, opacifiers, sequestrants, emollients, skin conditioners, fillers, whiteners and the like.
In preparing the shaving sticks of this invention, the components are preferably mixed in any order, preferably at elevated temperatures sufficient to liquify the sodium stearate, e.g. at about 75 to about 95C.
The following examples are only illustrative of preferred formulations according to this invention and are not to be regarded as limitative. All amounts and proportions referred to herein and in the appended claims are by weight un~ess otherwise indicated.
Shaving sticks made with these formulations conform to the desired 3~

objects hereof wi~il respect to solldi-ty cllaracteristics, lubricity, non-rancidity, post-rillsibility and/or post-sk;n feeling and the like.

% Example 1 _ -58.00 Glycerol Monooleate 18.00 Sodium stearate 20.00 Propylene glycol 4.00 Deionized water 100. 00 % Exam~ 2 _ 55.00 Glycerol monooleate 15.00 Sodium stearate 20.00 Propylene glycol 3.00 Deionized water 7.00 PEG (23) lauryl ether 100. 00 % Example 3 __ 77.65 Atlas G-3496 15.00 Sodium stearate 1) 4.00 Benzyl alcohol ( 3.00 Deionized water 0.3_ Perfume 100. 00 % Example 4 37.60 Atlas G-3496 8.00 Sodium stearate 6.00 Deionized water l0.00 Propylene glycol 37.60 POE (26) glycerol ether 0.35 Perfume (2) 0.20 Glydant 0.15 Methylparaben 0.10 Propylparaben 100. 00 % Example 5 61.65 Atlas G-3496 15.00 Sodium stearate 3.00 Deionized water 0.35 Perfume 20._ Propylene glycol 100.00 ~--r , . . .

% Exam~_6 __ _ ____.
58.20 Atlas G-3496 15.00 Sodium stearate 3.00 Deionized water 20.00 Propylene glycol 0.35 Perfume 0.20 Glydant 0.15 Methylparaben 0.10 Propylparaben 3.00 Ethylene glycol distearate 100. 00 (l) Aid against sloughing of stick formulation after wetting.

(2) Preservative, 55% dimethlol d;methyl hydantoin, Glyco Chemical Co. Trade Mark

(3) Preservative

(4) Opacifierl emollient This invention has been disclosed with respect to preEerred embodiments~ and various modifications and variations ~hereof obvious to those skilled in the art are to be included within the spirit and purview of this application and the scope of the appended claims.

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Claims (6)

1. THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
   PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
   
   l. A pre-shave assisting composition in stick form comprising, approximately by weight;
   I. 25 to 70% of glycerol monooleate II. 8 to 25% of sodium stearate, III. 0 to 50% of organic humectant, and IV. 1 to 10% of water, the ratio of I/II ranging from about 3/1 to about 5/1.
2. 2. A composition according to Claim 1 wherein component III comprises propylene glycol present in an amount of about 10 to about 30 wt. %.
3. 3. A composition according to Claim 2 further containing about 1 to about 10 wt. % of an ethoxameric nonionic surfactant.
4. 4. A composition according to any of Claims 1 to 3 containing, approxi-mately by weight, 30 to 60% of glycerol monooleate, 8 to 20% of sodium stearate, 10 to 50% of humectant, and 2 to less than 8% of water.
5. 5. A method comprising razor-shaving hair on the skin in the presence of a composition comprising approximately by weight, 30 - 60% of glycerol monooleate, 8 to 20% of sodium stearate, 10 to 50% of humectant, and 2 to less than 8% of water, the ratio of glycerol monooleate to sodium stearate ranging from about 3/1 to about 5/l.
6. 6. A method comprising razor-shaving hair on the skin in the presence of a composition as defined in any of Claims 1 to 3.