Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D9/00—Compositions of detergents based essentially on soap
  • C11D9/02—Compositions of detergents based essentially on soap on alkali or ammonium soaps
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0095—Solid transparent soaps or detergents
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D9/00—Compositions of detergents based essentially on soap
  • C11D9/04—Compositions of detergents based essentially on soap containing compounding ingredients other than soaps
  • C11D9/22—Organic compounds, e.g. vitamins
  • C11D9/30—Organic compounds, e.g. vitamins containing nitrogen

Definitions

• the invention relates to a transparent soap bar of exceptional clarity.
• Toilet soap is a mixture of long chain fatty acid salts and solvent, normally water, which together form three phases: solid crystal, liquid crystal and solution. Opacity as found with most soap bars results from the scattering of light at the interfaces between the several phase domains. In particular, the presence of many small solid crystals within the amorphous con­tinuum of a toilet bar causes incident light to pass through many interfaces. Since the several phases have different refractive indices, light will be scattered rather than pass through the bar. It should be noted that the solid crystals are by nature anisotropic. They have a refractive index that is dependent upon orientation. Consequently, the refractive index of the liquid phases cannot be simultaneously matched to the refractive indices of all orientations of the solid crystals.
• Solid crystals have also been avoided by crystallizing the soap mixture from a solution containing an evaporatable solvent such as ethanol.
• the procedure results in limiting the size of any solid crystals that might form.
• Illustrative in U.S. Patent 4,504,433 (Inui et al.) wherein tallow/palm oil was sapo­nified with aqueous sodium hydroxide in the presence of 20% etha­nol. To the combination was added white sugar, polyethylene glycol and glycerine which resultant composition was poured into casts for cooling and drying. The presence of sugar served to match the refractive indices of the several phases and to produce a transparent bar.
• U.S. Patent 2,820,768 (Fromont) is the classic transparent soap bar disclosure first coining the term "neutrogenous" indicating the presence of a substantial quantity acid neutralizing material, i.e. triethanolamine.
• the resultant bars contain a mixture of 35-40% each of sodium and triethanolam­monium soaps including substantial amounts of free triethanola­mine.
• Starting fats and oils are reported to preferably contain 30% castor oil for improving transparency and ricinoleates, derived from saponified castor oil, as acids for dissolving higher fatty acid salts. The ricinoleates are said to inhibit crystallization of the higher fatty acid salts inside the final soap on cooling. It should be noted that ricinoleates and castor oil are expensive components desirably absent from soap products for cost reasons.
• U.S. Patent 4,206,069 (Borrello) notes the cost problems and further indicates stickiness difficulties with prior art transparent bars. Under high humidity, it was recognized that known transparent bars are substantially hygroscopic whereupon transparency becomes lost. The patent suggests incorporating 10 to 65% of certain synthetic detergent components to harden the bar, reduce cost and improve transparency. Mixtures of sodium and triethanolammonium soaps are combined with the synthetic detergent. Included therein must be 10 to 45% of a non-volatile solvent such as an alkylene glycol or triethanolamine.
• an object of the present invention to provide a transparent soap bar of substantially improved clarity, such clarity being maintained during use of the bar.
• a transparent bar comprising:
• the present invention is a composition for a transparent bar that predominantly, and preferably exclusively, contains one isotropic phase.
• the bar comprises a mixture of alkanolammonium and alkali metal soaps in a solvent primarily comprising free alkanolamine and water.
• These components have, as noted above, been known as elements of transparent soap bars. It has, however, now been found that there are three critical ratios lying within a narrow range of values which permits substantial improvement of product clarity and color. Additionally, the bars of this invention do not require nor desirably contain special branched chain fatty acids, castor oil, ricinoleates, or other additives to achieve a transparent bar.
• the critical ratios found by this invention are as follows:
• free alkanolamine refers to any molar excess alkanolamine beyond that which is required for neutralization of any acid present in the bar com­position.
• Alkanolamine and alkanolammonium terms used throughout this disclosure are intended to include C1-C3 mono-, di- and tri-­alkanolamine and ammonium species.
• mono-, di-and/or tri-ethanolamine and ammonium ions are suitable for the present invention. Particularly preferred, however, is triethanolamine and triethanolammonium cation.
• the optimum values for the three ratios are interdepen­dent. For example, it is possible to compensate for a higher ratio of soap to solvent by increasing the ratio of water to alkanolamine, provided that this does not raise the dielectric constant of the solvent to the point where there is sufficient dissociation of the trialkanolammonium counterion. If this occurs, an anisotropic liquid crystal phase would arise.
• the desired values for these ratios will depend upon the particular chain length distribution and degree of unsaturation of the soaps present. For example, decreasing the average chain length or increasing the degree of unsaturation will increase the solubility of the soaps. A higher ratio of soap to solvent is thereby permitted. However, this also increases the tendency of the alkanolammonium counterion to dissociate, which then requires a lower ratio of water to alkano­lamine in the solvent. Adjusting the ratios in accord with the ranges outlined above permits a composition containing virtually no unsaturated soaps. It has been suggested that unsaturated soaps give transparent bars having a characteristic yellow color.
• Electrolytes serve both to reduce solubility of the soaps and increase the tendency to form anisotropic liquid crystals.
• a liquid solvent system is an essential component of the present invention.
• the solvent system must comprise components liquid at room temperature. Water and free alkanolamine will always be components of the solvent. However, additional water-miscible organic liquid materials when incorporated in the formulation must also be con­sidered in calculating the amount of solvent present.
• solvent under the heading of solvent must be considered monohydric and polyhydric alcohols such as ethanol, alkylene glycols, glycerine and the like; alkyl and aryl ethers such as diethyl ether, pheny­lethyl ether and the like; alkyl and aryl esters such as diethyl phthalate, ethyl acetate, isopropyl palmitate, diethyl succinate, and the like; alkyl and aryl ketones such as methylethyl ketone, acetone and the like; and mixtures thereof.
• alkyl and aryl ethers such as diethyl ether, pheny­lethyl ether and the like
• alkyl and aryl esters such as diethyl phthalate, ethyl acetate, isopropyl palmitate, diethyl succinate, and the like
• alkyl and aryl ketones such as methylethyl
• the composition described herein is prepared by heating and mixing the components until they dissolve. Thereafter, the composition is allowed to cool and solidify. The mixture should be quiescent during this solidification. Nevertheless, the mix­ture may be poured into individual molds before cooling and soli­dification, if desired. It may be particularly desirable for these molds to be transparent.
• transparent as used in this specification is intended to connote its usual dictionary definition.
• a transparent soap like glass, allows ready viewing of objects behind it.
• a translucent soap although allowing light to pass through, causes the light to be so scattered, as by a very small proportion of crystals or insolubles, that it will be impossible to clearly identify objects behind the translucent soap.
• a soap bar is deemed to be transparent if the maximum transmittance of light of any wavelength in the range of 200 to 800 nm through a sample 10 cm thick is at least 1%.
• a bar is deemed translucent if the maximum transmittance of such light through the sample is between 0.01% and 1%.
• a bar is deemed opaque if the maximum transmittance of such light is below 0.01%.
• This transmittance can be easily measured by placing a solid soap sample of the required thickness in the light beam path of a UV-VIS Spectrophotometer such as the Hewlett-Packard 8451A Diode Array Spectrophotometer.
• the advantage of this method of assessing transparency over previously published methods is that it is highly sensitive to optical clarity while independent of color.
• alkali metal or alkanolammonium salt of aliphatic alkane- or alkene monocarboxylic acids refers to one, two or three C1-C4 hydroxyalkyl groups substituted onto a nitrogen cation, triethanolammonium cation being the spe­cies of choice.
• Suitable alkali metal cations are those of potassium and sodium, the latter being much preferred.
• Soaps useful herein are the well known salts of natural or synthetic aliphatic (alkanoic or alkenoic) acids having about 12 to 22 carbon atoms, preferably about 12 to 18 carbon atoms. Soaps having the fatty acid distribution of coconut oil may pro­vide the lower end of the broad molecular weight range. Those soaps having the fatty acid distribution of peanut or rapeseed oil, or their hydrogenated derivatives, may provide the upper end of the broad molecular weight range.
• soaps having the fatty acid distribution of coconut oil or tallow, or mixtures thereof since there are among the more readily available fats.
• the proportion of fatty acids having at least 12 carbon atoms in coconut oil soap is about 85%. This proportion will be greater when mixtures of coconut oil and fats such as tallow, palm oil, or non-tropical nut oils or fats are used, wherein the principal chain lengths are C16 and higher.
• Coconut oil employed for the soap may be substituted in whole or in part by other "high-lauric” oils, that is, oils or fats wherein at least 50% of the total fatty acids are composed of lauric or myristic acids and mixtures thereof.
• These oils are generally exemplified by the tropical nut oils of the coconut oil class. For instance, they include: palm kernel oil, babassu oil, ouricuri oil, tucum oil, cohune nut oil, murumuru oil, jaboty kernel oil, khakan kernel oil, dika nut oil, and ucuhuba butter.
• a preferred alkali metal soap is a mixture of about 15% to about 20% coconut oil and about 80% to about 85% tallow. These mixtures contain about 95% fatty acids having about 12 to about 18 carbon atoms.
• the soap may be prepared from coconut oil, in which case the fatty acid content is about 85% of C12-C18 chain length.
• the soaps may contain unsaturation in accordance with commerically acceptable standards. Excessive unsaturation is normally avoided.
• sulfite salts may also be desirably present. These salts may be selected from the group consisting of bisulfite, hydrosulfite, metabisulfite, sulfite and mixtures thereof. Suitable salt counter-ions include alkali metal, alka­line earth metal, ammonium, alkyl or hydroxyalkyl ammonium cations and mixtures thereof. When present, the salts can constitute from about 0.03 to less than 3.0 wt.%, preferably from 0.03 to less than 0.2%, optimally from 0.03 to 0.06%.
• the transparent toilet bars of this invention as previously stated, have the potential for exceptionally low color provided suitable color reducing agents are present. In known transparent bars, color reducing agents are not as effective as with the present compositions.
• Adjunct materials including germicides, perfumes, and colorants may also be present. For cost and performance reasons it is, however, undesirable to include castor oil, ricinoleates, branched chain saturated fatty acids and amounts of soap greater than 50% of the total bar.
• Illustrative of the transparent compositions of the pre­sent invention are those listed in Tables I-A through I-E. These formulations were all prepared in the same manner as here outlined. Fatty acid, sodium metabisulfite, sodium borohydride and butyl hydroxyanisole (where present) and a small portion of the water were dissolved in triethanolamine. The mixture was then heated to approximately 80°C for 10 minutes. Solvents, including the balance of the water, propylene glycol, Polyol A-625, and ethanol (where present), glycerine, and the sodium soap were than added. A condenser was used to avoid loss of volatiles. Subsequent to combining the components, the mixture was stirred at 80°C until all components were dissolved. Perfume, if present, was added last. This mixture was then poured into molds and allowed to cool. The resulting soap bars were firm and clear.
• Fatty acid E-132 represents a lily stearic acid which is a mixture containing 50% palmitic and 45% stearic acids, obtainable commercially from the Emery Chemical Co. under the trademark Emersol 132.
• E-625 is a partially har­dened coconut fatty acid having 49% lauric and 19% myristic acid available as Emery 625 from the Emery Chemical Co. Soap, in all the experiments, refers to opaque toilet soap, a mixture of sodium tallowate and sodium cocoate, where the ratio of tallowate to cocoate is specifically indicated by the term "T".
• the tallow:coconut ratio indicated by the numerals 1, 2, 3 and 4 are 82/18, 64/36, 40/60 and 0/100, respectively.
• Moisture refers to the % water in the opaque toilet soap.
• Polyol refers to a hydro­genated starch hydrosylate containing 70% solids and 30% water, obtainable commercially from the Imperial Chemical Industries of America under the trademark Polyol A-625.
• BHA is butylhydroxylanisole, an antioxidant.
• This Example illustrates the improved performance obtainable by adherence to the aforedescribed critical ratios of soap to solvent, water to free triethanolamine, and triethanolam­monium to sodium soaps.
• hardness of the bar is designated either as “1” indicating firm or "2" indicating liquid. Only firm bars are acceptable within the context of this invention. Clarity is identified with a numeral 1, 2 or 3 indi­cating the resultant bar to be transparent, translucent or opaque, respectively. Only transparent bars are acceptable.
• the weight of soap refers to the total anhydrous weight of both triethanolammonium and sodium soaps.
• the weight of solvent refers to the total weight of free triethanolamine, water, and all water-miscible organic liquids.
• the weight or water refers to the total weight of water from all sources, including opaque toilet soap, Polyol, and added water.
• Table II-A investigates the effect of varying the weight ratio of total fatty acid soap to solvent.
• the weight ratio of water to triethanolamine and molar ratio of triethanolamine soap to sodium soap were kept constant within this series of experi­ments.
• Experiment 1 demonstrates that when the weight of total soap to solvent was 0.02 the bar hardness was unacceptably liquid, although the clarity was transparent. Above 0.02 weight ratio up to 1.00, bars of acceptable hardness and transparency were obtainable.
• Experiment 13 delineates the outer limit of the weight ratio total soap to solvent as being below 1.01. At 1.01, the bar was no longer transparent but only translucent.
• Table II-B investigates the variation in weight ratio of water to free triethanolamine.
• the weight ratio of total soap to solvent and molar ratio of TEA soap to sodium soap were kept constant.
• hardness was acceptable but the bar was opaque.
• hardness was acceptable but the bar was translucent.
• Experiments 16 through 23 illustrate weight ratios that provide acceptable hardness and clarity.
• Experiments 24 and 25 demonstrate that at 1.00 and 1.42 ratio, the bars become translucent.
• Table II-C investigates the variation in molar ratio of TEA soap to sodium soap.
• the weight ratio of total soap to solvent and water to free TEA were kept constant.
• Experiment 26 indicates that there must be at least some TEA soap present; i.e. the molar ratio of TEA soap to sodium soap must be greater than zero to obtain transparency.
• Experiments 27 to 33 define the acceptable range of the aforementioned molar ratio. Firm and transparent bars were obtained in this region.
• Experiments 34 through 37 show that molar ratios of 1.00 or higher result in opaque bars, and at very high ratios cause the composition to be liquid.
• Table II-D investigates random variations in all three ratios within the limits identified by Tables II-A through II-C. All compositions within this Table provide bars of both accep­table hardness and clarity.
• Table II-E investigates variations in the three ratios which are outside the limits defined by Tables II-A through II-C. All compositions listed within this Table have either or both a hardness and clarity problem.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Detergent Compositions (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (2)

Family

ID=8200014

Family Applications (1)

Country Status (6)

Cited By (7)

Families Citing this family (2)

Citations (4)

• 1988
  • 1988-03-31 ES ES198888302933T patent/ES2034203T3/es not_active Expired - Lifetime
  • 1988-03-31 AU AU14121/88A patent/AU600566B2/en not_active Expired
  • 1988-03-31 DE DE8888302933T patent/DE3873314T2/de not_active Expired - Fee Related
  • 1988-03-31 ZA ZA882340A patent/ZA882340B/xx unknown
  • 1988-03-31 EP EP19880302933 patent/EP0335026B1/fr not_active Expired - Lifetime
  • 1988-04-04 BR BR8801563A patent/BR8801563A/pt not_active IP Right Cessation

Patent Citations (4)

Also Published As

Similar Documents

Legal Events